objective questions based on fundamentals

CENTERS : MUMBAI / DELHI /AKOLA / LUCKNOW /NASHIK / PUNE / NAGPUR / BOKARO / DUBAI # 248

FINAL LAP - 2019CHEMICAL BONDING

CHEMICAL BONDING

OBJECTIVE QUESTIONS BASED ON FUNDAMENTALS

EXERCISE - 1(ONLY ONE ANSWER IS CORRECT)

Q.1 Which of the following diagram / statement is correct for the hybrid orbitals.(A) s + py z z(B) s + py + pz sp2 orbitals lie in the xy plane(C) ns + np3 + (n-1)d2 results octahedral geometry of sp3d2 hybrid orbitals.(D) None of these

Q.2 The type of overlap in the bridge bond existing in Al2(CH3)6 is(A) sp3 – sp3d – sp3 (B) sp3 – sp2 – sp3

(C) sp3 – s – sp3 (D) sp3 – sp3 – sp3

Q.3 Write the maximum number of atoms having same hybridisation in 2, 5-di-N-chloridothioimino-3, 4-diagonothiophene as shown below :

C = C

CS

CN

S

N

SCl Cl

C C

N N

(A) 4 (B) 5 (C) 6 (D) 8

Q.4 Which of the following statements are not correct?(A) Hybridization is the mixing of atomic orbitals(B) 2sp hybrid orbitals are formed from two p - atomic orbitals and one s- atomic orbitals(C) 2dsp hybrid orbitals are at 90º to one another(D) 32spd hybrid orbitals are directed towards the corners of a regular octahedron

Q.5 Which of the following overlaps is incorrect [assuming z-axis to be the internuclear axis]

(a) 2 py + 2 py 2 yp (b) 2 pz + 2 pz 2 zp

(c) 2 px + 2 px 2 xp (d) 1 s + 2 py 1 2 ys p

(A) ‘a’ & ‘b’ (B) ‘b’ & ‘d’ (C) only ‘d’ (D) None of these

Q.6 The correct order of increasing XOX bond angle is )or,( ClFHX :(A) OFOClOH 222 (B) OFOHOCl 222 (C) OHOClOF 222 (D) OClOHOF 222

Q.7 In the context of carbon, which of the following is arranged in the correct order of electronegativity :(A) 32 spspsp (B) spspsp 23 (C) 32 spspsp (D) 23 spspsp



Q.8 When ppss 22,22 and sp 22 orbitals overlap, the bond strength decreases in the order :(A) spsspp (B) sssppp (C) spppss (D) ppspss

Q.9 The bond energy order of He2+ and HeH+ is

(A) He2+ > HeH+ (B) HeH+ = He2

+ (C) HeH+ > He2+ (D) Can't be predicted

Q.10 The maximum covalency is equal to(A) the number of unpaired p-electrons(B) the number of paired d-electrons(C) the number of unpaired s and p-electrons(D) total number of unpaired electron in ground state or in existence state

Q.11 Comment on the CNC and HNN in CH3NCS and HN3 respectively.(A) less than 120° and less than 120° (B) Greater than 120° and less than 120°(C) less than 120° and greater than 120° (D) Greater than 120° and greater than 120°

Q.12 Among the following, van der Waals forces are maximum in(A) HBr (B) LiBr (C) LiCl (D) AgBr

Q.13 Among the following, the correct statement is :(A) Between NH3 and PH3, NH3 is a better electron donor because the lone pair of electrons occupies spherical ‘s’ orbital and is less directional(B) Between NH3 and PH3, PH3 is a better electron donor because the lone pair of electrons occupies sp3 orbital and is more directional(C) Between NH3 and PH3, NH3 is a better electron donor because the lone pair of electrons occupies sp3 orbital and is more directional(D) Between NH3 and PH3, PH3 is a better electron donor because the lone pair of electrons occupies spherical ‘s’ orbital and is less directional

Q.14 Oxidation state of ‘S’ in peroxodisulphuric acid and sodium tetrathionate(A) + 6 , + 5 , 0 (B) + 6, + 6, + 6 (C) + 6, + 4, + 2 (D) + 6, + 2, + 0

Q.15 The bond angle in 3PH is :(A) Much lesser than 3NH (B) Equal to that in 3NH(C) Much greater than in 3NH (D) Slightly more than in 3NH

Q.16 In a molecule of phosphorus (V)oxide, there are(A) 4P–P, 10P–O and 4P=O bonds (B) 12P–O and 4P=O bonds(C) 2P–O and 4P=P bonds (D) 6P–P, 12P–O and 4P=P bonds

Q.17 There is no S–S bond in:(A) S2O4

2– (B) S2O52– (C) S2O3

2– (D) S2O72–

Q.18 The presence of lone pair in NH3 can change its :(A) shape (B) angle as per hybridisation(C) (A) & (B) both (D) Neither (A) nor (B)



Q.19 In -4ICl , the shape is square planar. The number of bond pair-lone pair repulsion at 90° are:

(A) 6 (B) 8 (C) 12 (D) 4

Q.20 Arrange the following in order of decreasing ON bond length : 322 ,, NONONO

(A) 223 NONONO (B) 223 NONONO(C) 232 NONONO (D) 232 NONONO

Q.21 Which of the set of isomers of C6H4Cl2 is having equal dipole moment with C6H5Cl and C6H6 respectively(A) ortho and meta (B) meta and para(C) ortho and para (D) para and ortho

Q.22 In which of following cases C–C bond length will be highest.(A) CH3–CF3 (B) FCH2–CH2F (C) F2CH–CHF2 (D) CF3–CF3

Q.23 The cationic part of solid Cl2O6 is having the "___________" shape.(A) linear (B) angular (C) Tetrahedron (D) undefined

Q.24 Borax is actually made of two tetrahedra and two triangular units joined together and should be writtenas: Na2[B4O5(OH)4]·8H2OConsider the following statements about borax:a. Each boron atom has four B–O bondsb. Each boron atom has three B–O bondsc. Two boron atoms have four B–O bonds while other two have three B–O bondsd. Each boron atom has one –OH groupsSelect correct statement(s):(A) a, b (B) b, c (C) c, d (D) a, c

Q.25 Hybridization of carbon in 23OC is :(A) sp (B) 2sp (C) 3sp (D) dsp3

Q.26 Which of the following has been arranged in order of decreasing bond length ?(A) OSOClOP (B) OClOSOP (C) OPOClOS (D) OPOSOCl

Q.27 The shapes of 44 , PClPCl and 5AsCl are respectively :

(A) square planar, tetrahedral and see-saw(B) tetrahedral, see-saw and trigonal bipyramidal(C) tetrahedral, square planar and pentagonal bipyramidal(D) trigonal bipyramidal, tetrahedral and square pyramidal

Q.28 5PCl exists but 5NCl does not because :(A) Nitrogen has no vacant d-orbitals (B) 5NCl is unstable(C) Nitrogen atom is much smaller than p (D) Nitrogen is highly inert

Q.29 The correct order of increasing s-character (in percentage) in the hybrid orbitals of following molecules/ions is:

(I) 23CO (II) 4XeF (III)

3I (IV) NCl3 (V) BeCl2(A) II < III < IV < I < V (B) II < IV < III < V < I(C) III < II < I < V < IV (D) II < IV < III < I < V



Q.30 Molecular shapes of SF4, CF4 and XeF4 are:(A) the same, with 2, 0 and1 lone pair of electrons respectively(B) the same, with 1, 1 and 1 lone pair of electrons respectively(C) different with 0, 1 and 2 lone pair of electrons respectively(D) different with 1, 0 and 2 lone pair of electrons respectively

Q.31 Which has higher bond energy :(A) 2F (B) 2Cl (C) 2Br (D) 2I

Q.32 C—H bond distance is the longest in:(A) C2H2 (B) C2H4 (C) C2H6 (D) C2H2Br2

Q.33 Maximum bond energy is in :(A) 2F (B) 2N (C) 2O (D) equal

Q.34 In the cyanide ion the negative charge is on(A) C (B) N (C) Both C and N (D) Resonate between C and N

Q.35 The bond angle and hybridization in ether )( 33OCHCH is :(A) 3,15º106 sp (B) 3,13º104 sp (C) 3,º110 sp (D) None of these

Q.36 A: tetracyanomethane B: Carbondioxide C: Benzene D: 1, 3–buta–di–eneRatio of and bonds is in order:(A) A=B<C<D (B) A=B<D<C (C) A=B=C=D (D) C<D<A<B

Q.37 The enolic form of acetone contains :(A) 9 sigma, 1 pi bond and 2 lone pairs (B) 8 sigma, 2 pi bond and 2 lone pairs(C) 10 sigma, 1 pi bond and 1 lone pairs (D) 9 sigma, 2 pi bond and 1 lone pairs

Q.38 The number of -bond and -bond in HCP are respectively(A) 2 and 2 (B) 1 and 3 (C) 2 and 1 (D) None

Q.39 (C—Cl) bond in CH2=CH–Cl (vinyl chloride) is stabilised in the same way as in:(A) benzyl chloride (B) ethyl chloride (C) chlorobenzene (D) allyl chloride

Q.40 The correct order of acidic strength of oxy-acids of chlorine is(A) HCIO < HCIO2 < HCIO3 < HCIO4 (B) HCIO4 < HCIO3 < HCIO2 < HCIO(C) HCIO > HCIO4 > HCIO3 > HCIO2 (D) HCIO4 < HCIO2 > HCIO3 > HCIO

Q.41 CH2 COOH

COOH C150,OP 104 X

Compound (X) is(A) malonic acid (B) carbon suboxide (C) tartaric acid (D) acetic acid

Q.42 Mg2C3 reacts with water forming propyne, C34– has:

(A) two sigma and two pi bonds (B) three sigma and one pi bonds(C) two sigma and one pi bonds (D) two sigma and three pi bonds


FINAL LAP - 2019CHEMICAL BONDINGQ.43 How many sigma and pi bonds are present in tetracyanoethylene ?

(A) Nine and nine (B) Five and nine (C) Nine and seven (D) Eight and eight

Q.44 HBH bond angle in 4BH is :

(A) 180º (B) 120º (C) 109º (D) 90º

Q.45 The hydration of ionic compounds involves :(A) Evolution of heat (B) Weakening of attractive forces(C) Dissociation into ions (D) All of these

Q.46 For which of the following crystalline substances does the solubility in water increase upto 32º C andthen decrease rapidly ?(A) OH2.CaCl 22 (B) OH10.SONa 242 (C) OH7.FeSO 24 (D) Alums

Q.47 Among 222 ,, BaOAlOKO and 2NO unpaired electron is present in :

(A) 2KO only (B) 2NO and 2BaO (C) 2KO and

2AlO (D) 2BaO only

Q.48 If a molecule 3MX has zero dipole moment, the sigma bonding orbitals used by M (atm. no. < 21) are :(A) pure p (B) sp hybrid (C) 2sp hybrid (D) 3sp hybrid

Q.49 Identify isostructural pairs from NF3(I) , NO3-(II) , BF3(III) , H3O+(IV), HN3 (V)

(A) I & II, III & IV (B) I & V, II & III (C) I & IV, II & III (D) I & IV, III & V

Q.50 Which of the following species are hypervalent?1. ClO4

–, 2. BF3, 3. SO42– , 4. CO3

2–

(A) 1, 2, 3 (B) 1, 3 (C) 3, 4 (D) 1, 2

Q.51 Boron forms BX3 type of halides. The correct increasing order of Lewis-acid strength of these halides is(A) BF3 > BCl3 > BBr3 > BI3 (B) BI3 > BBr3 > BCl3 > BF3(C) BF3 > BI3 > BCl3 > BBr3 (D) BF3 > BCl3 > BI3 > BBr3

Q.52 Which one of the following statements is not true regarding diborane?(A) It has two bridging hydrogens and four perpendicular to the rest.(B) When methylated, the product is Me4B2H2.(C) The bridging hydrogens are in a plane perpendicular to the rest.(D) All the B–H bond distances are equal.

Q.53 The structure of diborane (B2H6) contains(A) Four (2C–2e–) bonds and two (2C–3e–) bonds(B) Two (2C–2e–) bonds and two (3C–2e–) bonds(C) Four (2C–2e–) bonds and four (3C– 2e–) bonds(D) None

Q.54 The molecular shapes of diborane is shown:Consider the following statements for diborane:1. Boron is approximately sp3 hybridised2. B–H–B angle is 180°3. There are two terminal B–H bonds for each boron atom4. There are only 12 bonding electrons availableOf these statements:(A) 1, 3 and 4 are correct (B) 1, 2 and 3 are correct(C) 2, 3 and 4 are correct (D) 1, 2 and 4 are correct


FINAL LAP - 2019CHEMICAL BONDINGQ.55 Select correct statement about hydrolysis of BCl3 and NCl3

(A) NCl3 is hydrolysed and gives HOCl but BCl3 is not hydrolysed.(B) Both NCl3 and BCl3 on hydrolysis gives HCl(C) NCl3 on hydrolysis gives HOCl but BCl3 gives HCl.(D) Both NCl3 and BCl3 on hydrolysis gives HOCl.

Q.56 Which of the following properties describes the diagonal relationship between boron and slicon?(A) BCl3 is not hydrolysed while SiCl4 can be hydrolysed(B) Both form oxides; B2O3 is amphoteric; SiO2 is acidic(C) Both dissolve in cold and dilute nitric acid(D) Borides and silicides are hydrolysed by water

Q.57 Type of hybridisation in transition state of SeF4, when it undergoes in hydrolysis(A) sp3d (B) sp3d2 (C) dsp3 (D) sp3

Q.58 Which of the following halides cannot be hydrolysed?(I) TeF6 (II) SF6 (III) NCl3 (IV) NF3Choose the correct code :(A) III & IV (B) I, II & III (C) I, II & IV (D) II & IV

Q.59 The critical temperature of water is higher than that of 2O because the OH2 molecule has :(A) fewer electrons than 2O (B) two covalents bonds(C) V - shape (D) dipole moment

Q.60 Ethanol has a higher boiling point than dimethyl ether though they have the same molecular weight. Thisis due to :(A) resonance (B) coordinate bonding(C) hydrogen bonding (D) ionic bonding

Q.61 Arrange the following in order of decreasing boiling point :(I) n-Butane (II) n-Butanol (III) n-Butyl chloride (IV) Isobutane(A) IIIIIIIV (B) IIIIIIIV (C) IVIIIIII (D) IVIIIIII

Q.62 Which of the following compounds would have significant intermolecular hydrogen bonding ?4423 ,,, CHONOHCHHF

(A) 42, ONHF (B) OHCHCHHF 34 ,,(C) OHCHHF 3, (D) 43 , CHOHCH

Q.63 Which of the following molecules are expected to exhibit intermolecular H–bondingI. Acetic acid II. o-nitrophenol III. m–nitrophenol IV. o–boric acid(A) I, II, III (B) I, II, IV (C) I, III, IV (D) II, III, IV

Q.64 Intramolecular hydrogen bonding is found in :(A) Salicylaldehyde (B) Water (C) Acetaldehyde (D) Phenol

Q.65 The pairs of bases in DNA are held together by :(A) Hydrogen bonds (B) Ionic bonds (C) Phosphate groups (D) Deoxyribose groups

Q.66 The volatility of HF is low because of :(A) its low polarizability (B) the weak dispersion interaction between the molecules(C) its small molecular mass (D) its strong hydrogen bonding


FINAL LAP - 2019CHEMICAL BONDINGQ.67 Which one of the following does not have intermolecular H-bonding?

(A) H2O (B) o-nitro phenol (C) HF (D) CH3COOH

Q.68 Which of the following exhibit/s H-bonding?(A) CH4 (B) H2Se (C) N2H4 (D) H2S

Q.69 Two ice cubes are pressed over each other and unite to form one cube. Which force is responsible forholding them together :(A) van der Waal’s forces (B) Covalent attraction(C) Hydrogen bond formation (D) Dipole-dipole attraction

Q.70 Which has maximum dipole moment?

(A) (B) (C) (D)

Q.71 Which of the following has been arranged in order of decreasing dipole moment ?(A) ICHBrCHFCHClCH 3333 (B) ICHBrCHClCHFCH 3333 (C) FCHICHBrCHClCH 3333 (D) BrCHICHClCHFCH 3333

Q.72 The experimental value of the dipole moment of HCl is 1.03 D. The length of the ClH bond isÅ275.1 . The percentage of ionic character in HCl is :

(A) 43 (B) 21 (C) 17 (D) 7

Q.73 The total number of valence electrons in 4.2g of 3N ion are :

(A) 2.2 N (B) 4.2 N (C) 1.6 N (D) 3.2 N

Q.74 Which of the following has the least dipole moment(A) 3NF (B) CO2 (C) 2SO (D) 3NH

Q.75 Amongst 22 and,, MgClBeClRbClLiCl , the compounds with the greatest and the least ionic character,,respectively are :(A) RbClLiCl and (B) 2and BeClRbCl (C) 2and MgClRbCl (D) 22 and BeClMgCl

Q.76 The polarizibility of the following compounds is/are(A) I- > Br - > Cl- > F- (B) I- > Br - > F- > Cl-(C) I- < Br - < Cl- < F- (D) I- < Br - < F- < Cl-

Q.77 Compound with maximum ionic character is formed from :(A) Na and Cl (B) Cs and F (C) Cs and I (D) Na and F

Q.78 The melting point of 3AlF is 104º C and that of 4SiF is - 77º C (it sublimes) because :(A) there is a very large difference in the ionic character of the FAl and FSi bonds(B) in 3AlF , 3Al interacts very strongly with the neighbouring F ions to give a three dimensionalstructure but in 4SiF no such interaction is possible(C) the silicon ion in the tetrahedral 4SiF is not shielded effectively from the fluoride ions whereas in

3AlF , the 3Al ion is shielded on all sides(D) the attractive forces between the 4SiF molecules are strong whereas those between the 3AlF moleculesare weak


FINAL LAP - 2019CHEMICAL BONDINGQ.79 Which of the following equilibria would have the highest value of pK at a common temperature ?

(A) 23 COMgOMgCO (B) 23 COCaOCaCO (C) 23 COSrOSrCO (D) 23 COBaOBaCO

Q.80 Which of the following sets of characteristics leads to the increase in solubility of ionic substances ?(A) High dipole moment, strong attraction by an ion and large solvation energy(B) Low dipole moment, weak attraction by an ion and high solvation energy(C) High dipole moment, strong attraction by an ion and low solvation energy(D) High dipole moment, weak attraction by an ion and large solvation energy

Q.81 The solubility of anhydrous AlCl3 and hydrous AlCl3 in diethyl ether are S1 and S2 respectively. Then(A) S1 = S2 (B) S1 > S2 (C) S1 < S2 (D) S1 < S1 but not S1 = S2

Q.82 During the formation of a molecular orbital from atomic orbitals, probability of electron density is:(A) minimum in the nodal plane (B) maximum in the nodal plane(C) zero in the nodal plane (D) zero on the surface of the lobe

Q.83 Pick out the incorrect statement?(A) N2 has greater dissociation energy than N2

+

(B) O2 has lower dissociation energy than O2+

(C) Bond length in N2+ is less than N2

(D) Bond length in NO+ is less than in NO.

Q.84 Which of the following species is paramagnetic ?(A) NO (B) 2

2O (C) CN (D) CO

Q.85 Bond order of 2Be is :(A) 1 (B) 2 (C) 3 (D) 0

Q.86 A simplified application of MO theory to the hypothetical ‘molecule’ OF would give its bond order as :(A) 2 (B) 1.5 (C) 1.0 (D) 0.5

Q.87 Number of anti bonding electrons in 2N is :(A) 4 (B) 10 (C) 12 (D) 14

Q.88 The bond order depends on the number of electrons in the bonding and antibonding orbitals. Which ofthe following statements is /are correct about bond order?(A)Bond order cannot have a negative value.(B) It always has an integral value.(C) It is a nonzero quantity.(D) It can assume any value-positive or negative, integral or fractional, including zero.

Q.89 In the formation of 2N from 2N , the electron is removed from :

(A) orbital (B) orbital (C) * orbital (D) * orbital

Q.90 Which of the following is true ?

(A) energybondlengthbond1orderBond (B) energybond

1length bondorderBond

(C) energybond1

lengthbond1orderBond (D) energybondlength bondorderBond



Q.91 Which of the following has fractional bond order :(A) 2

2O (B) 22O (C) 2

2F (D) 2H

Q.92 How many unpaired electrons are present in 2N :

(A) 1 (B) 2 (C) 3 (D) 4

Q.93 Si2O76– anion is obtained when

(A) no oxygen of a SiO4 tetrahedron is shared with another SiO4 tetrahedron.(B) one oxygen of a SiO4 tetrahedron is shared with another SiO4 tetrahedron.(C) two oxygen of a SiO4 tetrahedron are shared with another SiO4 tetrahedron.(D) three or all four oxygens of a tetrahedron are shared with other SiO4 tetrahedron.

Q.94 Match list I with list II and select the correct answer:List I (species) List II (O–N–O angle)

A. NO2+ 1. 180°

B. NO2 2. 134°C. NO2

– 3. 120°D. NO3

– 4. 115°5. 109°

A B C D A B C D(A) 5 4 3 2 (B) 5 2 4 3(C) 1 2 4 3 (D) 1 4 3 2



MISCELLANEOUS QUESTIONS

EXERCISE - 2 (ONE & MORE ANSWER IS CORRECT)

Q.1 The experimental result says that two iodine atoms are in different environments and predict the allpossible incorrect arrangement for I2Cl4Br2.

(A) I ICl

Cl

Cl Br

Cl Br(B) I I

Cl

Cl Cl

Br

Cl

Br

(C) I ICl

Cl Cl

BrCl

Br(D) I I

Br

Br

Cl

Cl

Cl

ClQ.2 Choose the correct order for the given properties.

(A) MgSO4 < SrSO4 < BaSO4 : Thermal stability order(B) BeC2O4 < CaC2O4 < BaC2O4 : Solubility in water(C) LiCl > NaCl > KCl : Melting point order(D) BeF2 > CaF2 > SrF2 : Covalent character order

Q.3 Which have fractional bond order?(A) O2

+ (B) O2 (C) NO (D) H2

+

Q.4 Which has (have) zero value of dipole moment?(A) XeF4 (B) CHCl3 (C) CO2 (D) Cl Cl

Q.5 Which of the following have planar structure?

(A) 3I (B) H2O (C) PCl5 (D) XeF4

Q.6 Which of the following have dipole moment ?(A) nitrobenzene (B) p-chloronitrobenzene(C) m-dichlorobenzene (D) o-dichlorobenzene

Q.7 In the structure of H2CSF4, which of the following statement is/are correct?(A) Two C–H bonds are in the same plane of axial S–F bonds.(B) Two C–H bonds are in the same plane of equitorial S–F bonds.(C) Total six atoms are in the same plane.(D) Equitorial S–F plane is perpendicular to nodal plane of –bond.

Q.8 Which of the following compounds contain/s both ionic and covalent bonds?(A) NH4Cl (B) KCN (C) CuSO4·5H2O (D) NaOH

Q.9 Which of the following statements are not correct?

(A) All C–O bonds in 23CO are equal but not in H2CO3.

(B) All C–O bonds in 2HCO are equal but not in HCO2H

(C) C–O bond length in 2HCO is longer than C–O bond length in 2

3CO .

(D) C–O bond length in 2HCO and C–O bond length in 2

3CO are equal.


FINAL LAP - 2019CHEMICAL BONDINGQ.10 Resonance occurs due to the

(A) delocalization of a lone pair of electrons (B) delocalization of sigma electrons(C) delocalization of pi electrons (D) migration of protons

Q.11 Which of following stability order is/are correct due to inert pair effect.(A) Hg° > Hg2+ (B) Bi3+ < Bi5+ (C) Pb2+ > Pb4+ (D) Fe2+ < Fe3+

Q.12 Which of the following statements is/are true?(A) Covalent bonds are directional(B) Ionic bonds are nondirectional(C) A polar bond is formed between two atoms which have the same electronegativity value.(D) The presence of polar bonds in a polyatomic molecule suggests that it has zero dipole moment

Q.13 Which of the following have identical bond order?(A) 2

2O (B) NO (C) CN (D) CN

Q.14 Which of the following statement is/are correct(A) The peroxide ion has a bond order of 1 while the oxygen molecule has a bond order of 2(B) The peroxide ion has a weaker bond than the dioxygen molecule has.(C) The peroxide ion as well as the dioxygen molecules are paramagnetic(D) The bond length of the peroxide ion is greater than that of the dioxygen molecule

Q.15 Given the species : CNCON ,,2 and NO . Which of the following statements are true for these(A) All species are paramagnetic (B) The species are isoelectronic(C) All the species have dipole moment (D) All the species are linear

Q.16 Which of the following have unpaired electron(s)(A)

2O (B) 2O (C) NO (D)

2H

Q.17 Colour of which of the following is attributed to charge transfer spectrum ?(A) 4KMnO (B) 2KO (C) 722 OCrK (D) AgI

Q.18 What is the state of hybridisation of Xe in cationic part of solid XeF6.(A) sp3d3 (B) sp3d2 (C) sp3d (D) sp3

Q.19 Rotation around the bond (between the underlined atoms) is restricted in :(A) 42 HC (B) 22 OH (C) 22HC (D) 62 HC

Q.20 According to MOT (Molecular Orbital Theory), the molecular orbitals are formed by mixing of atomicorbitals through LCAO (linear combination of atomic orbitals). The correct statement(s) about molecularorbitals is/areStatement (a) :bonding molecular orbitals are formed by addition of wave-functions of atomic

orbitals of same phaseStatement (b) : anti-bonding molecular orbitals are formed by subtraction of wave-functions of

atomic orbitals of same phaseStatement (c) : non-bonding molecular orbitals do not take part in bond formation because they

belong to inner shellsStatement (d) : anti-bonding molecular orbitals provide stability to molecules while bonding

molecular orbitals make the molecules unstable.(A) Statement a, d (B) Statement a, b, c (C) Statement a, b, d (D) Statement a, b

Q.21 No XX bond exists in which of the following compounds having general form of 62HX ?(A) 62HB (B) 62HC (C) 62HAl (D) 62HSi



Q.22 Which of the following species is (are) isostructural with 4XeF ?(A)

4ICl (B) 5I (C)

4BrF (D) 4XeO

Q.23 Which one of the following compounds has bond angle as nearly 90º ?(A) 3NH (B) SH 2 (C) OH2 (D) 6SF

Q.24 The linear structure is assumed by :(A) 2SnCl (B) NCO (C) 2CS (D)

2NO

Q.25 Which of the following statements is/are correct ?(A)

2NH shows 2sp hybridisation whereas 2NH shows 3sp hybridisation

(B) 4)(OHAl has a regular tetrahedral geometry

(C) 2sp hybridized orbitals have equal s- and p- character(D) Usually hybridized orbitals form - bonds

Q.26 Choose the correct option for the following molecule in view of chemical bonding

(A) non-planar (B) 0 (C) A & B both (D) = 0

Q.27 Of the following isoelectronic & isostructural species areNO3

—, ClO3—, SO3 & CO3

2—

(A) NO3— & CO3

2— (B) SO3 & CO32

(C) NO3 & ClO3— (D) CO3

2— & ClO3—

Q.28 Shape of 3NH is very similar to :(A) 2

3SeO (B) 3CH (C) 3BH (D)

3CH

Q.29 Polarization may be called the distortion of the shape of an anion by an adjacently placed cation. Whichof the following statements is/are incorrect:(A) Minimum polarization is brought about by a cation of low radius(B) A large cation is likely to bring about a large degree of polarization(C) Maximum polarization is brought about by a cation of high charge(D) A small anion is likely to undergo a large degree of polarization

Q.30 Pick out among the following species isoelectronic with 2CO :(A)

3N (B) )(CNO (C) 2)(NCN (D) 2NO

Q.31 Which is correct statement?As the s-character of a hybrid orbital decreases(I) The bond angle decreases (II) The bond strength increases(III) The bond length increases (IV) Size of orbital increases(A) (I), (III) and (IV) (B) (II), (III) and (IV)(C) (I) and (II) (D) All are correct

Q.32 Resonating strctures of a molecule should have:(A) identical bonding (B) identical ararngement of atoms(C) nearly the same energy content (D) the same number of paired electrons



Q.33 Which of the following conditions apply to resonating structures ?(A) The contributing structures should have nearly similar energies(B) The contributing structures should be represented such that like charges reside on atoms that are farapart(C) The more electropositive element should preferably have positive charge and the more electronegativeelement have negative charge(D) The contributing structures must have the same number of unpaired electrons

Q.34 A -bond may between two xp orbitals containing one unpaired electron each when they approacheach other appropriately along :(A) x - axis (B) y - axis (C) z - axis (D) any direction

Q.35 During the complete combustion of methane CH4, what change in hybridisation does the carbon atomundergo?(A) sp3 to sp (B) sp3 to sp2 (C) sp2 to sp (D) sp2 to sp3

Q.36 The octet rule is not obeyed in :(A) 2CO (B) 3BCl (C) 5PCl (D) 4SiF

Q.37 A, B, C are three substances. A does not conduct electricity in the soild, molten state and aqueous solution.B conducts electricity both in the fused and aqueous states, while C conducts electricity only in the aqueousstate. In solid state neither B nor C conducts electricity. Which of the following statements is/are true regardingA, B and C ?(A) A has polar covalent linkage (B) A has nonpolar covalent linkage(C) B is ionic in nature (D) Cation formed by C is highy polarizing

Q.38 Three centre – two electron bonds exist in :(A) B2H6 (B) Al2(CH3)6 (C) BeH2(s) (D) BeCl2(s)

Q.39 Which of the following statement(s) is/are correct regarding ionic compounds ?(A) They are good conductors of electricity at room temperature(B) They are always more soluble in polar solvents than covalent compounds(C) They consists of ions(D) They generally have high melting and boling points

Q.40 Most ionic compounds have :(A) high melting points and low boiling points(B) high melting points and nondirectional bonds(C) high solubilities in polar solvents and low solubilities in nonpolar solvents(D) three-dimentional network structures, and are good conductors of electricity in the molten state

Q.41 When an inorganic compound (X) having 3e-2e as well as 2e-2e bonds reacts with ammonia gas at acertain temperature, gives a compound (Y) iso-structural with benzene. Compound (X) with ammoniaat a high temperature, produces a hard substance (Z). Then(A) (X) is B2H6 (B) (Z) is known as inorganic graphite(C) (Z) having structure similar to graphite (D) (Z) having structure similar to (X)

Q.42 Select correct statement about B2H6(A) Bridging groups are electron-deficient with 12 valence electrons(B) It has 2c - 2e B–H bonds(C) It has 3c - 2e B–H–B bonds(D) All of above are correct statements

Q.43 Which of the following pairs of nitrates gives the same gaseous products on thermal decomposition?(A) KNO3 and Pb(NO3)2 (B) KNO3 and NaNO3(C) Pb(NO3)2 and Cu(NO3)2 (D) NaNO3 and Ca(NO3)2



ANSWER KEY

EXERCISE–IQ.1 D Q.2 D Q.3 C Q.4 A Q.5 C Q.6 B Q.7 AQ.8 B Q.9 C Q.10 D Q.11 B Q.12 D Q.13 C Q.14 AQ.15 A Q.16 B Q.17 D Q.18 B Q.19 B Q.20 B Q.21 BQ.22 B Q.23 B Q.24 C Q.25 A Q.26 B Q.27 B Q.28 AQ.29 A Q.30 D Q.31 B Q.32 C Q.33 B Q.34 A Q.35 CQ.36 A Q.37 A Q.38 A Q.39 C Q.40 A Q.41 B Q.42 AQ.43 A Q.44 C Q.45 D Q.46 B Q.47 A Q.48 C Q.49 CQ.50 B Q.51 B Q.52 D Q.53 D Q.54 A Q.55 C Q.56 DQ.57 B Q.58 D Q.59 D Q.60 C Q.61 D Q.62 C Q.63 CQ.64 A Q.65 A Q.66 D Q.67 B Q.68 C Q.69 C Q.70 AQ.71 A Q.72 C Q.73 C Q.74 B Q.75 B Q.76 A Q.77 BQ.78 B Q.79 A Q.80 A Q.81 B Q.82 C Q.83 C Q.84 AQ.85 D Q.86 B Q.87 A Q.88 D Q.89 A Q.90 A Q.91 DQ.92 A Q.93 B Q.94 C

EXERCISE–IIQ.1 B,C,D Q.2 A,D Q.3 A,B,C,D Q.4 A,C,DQ.5 A,B,D Q.6 A,B,C,D Q.7 A,C,D Q.8 A,B,C,DQ.9 C,D Q.10 A,C Q.11 A,C Q.12 A,BQ.13 A,B,C Q.14 A,B,D Q.15 B,D Q.16 A,B,C,DQ.17 A,C Q.18 B Q.19 A,B,C Q.20 DQ.21 A,C Q.22 A,C Q.23 B,D Q.24 B,C,DQ.25 A,B,D Q.26 D Q.27 A Q.28 A,BQ.29 A,B,D Q.30 A,B,C Q.31 A Q.32 B,C,DQ.33 A,B,C,D Q.34 B,C Q.35 A Q.36 B,CQ.37 B,C,D Q.38 A,B,C Q.39 C,D Q.40 B,C,DQ.41 A,B,C Q.42 B,C Q.43 B,C


FINAL LAP - 2019COORDINATION COMPOUND

COORDINATION COMPOUND

SUBJECTIVE QUESTIONS BASED ON FUNDAMENTALS

EXERCISE - 1(ONLY ONE ANSWER IS CORRECT)

SECTION (A) : NOMENCLATURE OF COORDINATION COMPOUNDS

1. Name the following compounds(a) [Co(NH3)6]Cl3, Prepared in 1798 by B.M. Tassaert and considered to be first complex salt prepared.

(b) [Rh(NH3)5I]I2, A yellow colored complex obtained by heating [Rh(NH3)5(H2O)]I3 above 1000C.

(c) [Fe(CO)5], A highly toxic volatile liquid

(d) [Fe(C2O4)3]3–, The ion formed when Fe2O3 rust is dissolved in oxalic acid H2C2O4.

(e) [Cu(NH3)4]SO4, A deep blue compound obtained when CuSO4 is treated with excess of NH3

(f) Na[Cr(OH)4], The compound formed when Cr(OH)3 ppt is dissolved in excess of NaOH.

(g) Co(gly)3, A complex that contains the anion of amino acid glycine.

(h) [Fe(H2O)5(NCS)]2+, The red complex ion formed in the qualitative analysis test of Fe3+ ion.

(i) K2[HgI4], Alkaline solutionof this complex is called Nessler’s Reagent.

(j) Co[Hg(SCN)4], Deep blue crystalline ppt obtained in qualitative detection of Hg2+.

(k) Fe4[Fe(CN)6]3, Prussian blue, deep blue colored complex obtained in detection of Fe2+

(l) K3[Co(ONO)6], Potassium cobaltinitrite or Fischer salt yellow ppt, obtained in detection of Co2+.

(m) [Ni(dmg)2], Rosy red ppt obtained in detection of Ni2+ ions

(n) K2[PtCl6], yellow ppt obtained in detection of potassium ions.

(o) Na2[Fe(CN)5NO+], Sodium nitroprusside used for detection of sulphide ions/sulphur

(p) [Fe(H2O)5(NO+)]SO4, Brown ring complex, obtained in detection of Fe2+ ions

(q) Fe3[Fe(CN)6]2, Turnbull’s blue, whose composition is found to be same as that of prussian blue.

(r) [Cu(CN)4]3–, colorless ppt obtained in detection of Cu2+ on adding excess of KCN solution.

(s) [Cd(CN)4]2–, colorless, unstable complex of Cd2+ obtained on adding excess of KCN solution.

(t) (NH4)2[PtCl6], Only few compounds of ammonium ions are ppt, this is one of these, a yellow ppt.

2. Name the following compounds

(a) [Co(en)2Br(ONO)]+1 ; (b) [Co(NH3)6] [Co(ONO)6] ; (c) [Co(NH3)5(CO3)]Cl

(d) [Pt(NH3)4Cl2] [PtCl4] ; (e) [Co(en)3]2(SO4)3 ; (f) [Cr(PPh3)(CO)5]

(g) [(CO)5Mn-Mn(CO)5] ; (h) K[PtCl3(-C2H4)]; (i) Cr(-C6H6)2

(j) [NH(CH3)3][WCl(CO)5] ; (k) [Co(NH3)4(OH2)2][BF4]3 ; (l) Na4[Cu6(S2O3)5]

(m) Ba[Zr(OH)2(ONO)2(ox)] ;(n) [Co(NH3)6][Co(C2O4)3]

3. Write down the formulae of the following compounds(a) diamminetriaquahydroxochromium (III) nitrate

(b) tetrakis(pyridine)platinum(II) tetraphenylborate(III)

(c) dibromotetracarbonyliron (II)

(d) ammonium diamminetetrakis(isothiocyanato)chromate(III).

(e) Pentaamminedinitrogenruthenium(II) chloride



(f) Bis(cyclopentadienyl)iron(II)

(g) Barium dihydroxodinitrito-O-oxalatozirconate(IV)

(h) Tetrapyridineplatinum(II) tetrachloronickelate(II)

SECTION (B) : BONDING IN COORDINATION COMPOUNDS(Initial bonding theories and EAN rule, Valence bond theory)

1. (You should the data given in the table of this question, there can be some objective questions based on thisdata in other examinations)Werner conducted many experiments to establish the formula of complexes, one of these were conductivitymeasurements. On the basis of the experiments performed he obtained the following values of conductivityfor different type of complexes

Type of complex Electrical ConductivityNonelectrolyte 0 – 10 (due to impurities)1:1 Electrolyte 90 – 1301:2 or 2:1 Electrolyte 230 – 2901:3 or 3:1 Electrolyte 390 – 4501:4 Electrolyte 500 – 550

On the basis of above table Match the following two columnsCOLUMN A COLUMN B

Formula of compound Conductivity Correct Werner’s Representation(a) PtCl4.2NH3 – 6.99 (i) [Cr(NH3)5Cl]Cl2(b) PtCl4.NH3.KCl – 106.8 (ii) [Co(NH3)5Br]Br2

(c) CrCl3.5NH3 – 260.2 (iii) [Cr(NH3)6]Cl3(d) PtCl4.2KCl – 256.8 (iv) [Pt(NH3)2Cl4]

(e) CrCl3.6NH3 – 441.7 (v) [Pt(NH3)6]Cl4(f) PtCl4.6NH3 – 522.9 (vi) [Pt(NH3)3Cl3]Cl

(g) CoBr3.5NH3 – 257.6 (vii) K2[PtCl6]

(h) PtCl4.3NH3 – 96.8 (viii) K[Pt(NH3)Cl5]

2. 1 gm of complex [Cr(H2O)5Cl]Cl2 . H2O was passed through a cation exchanger to produce HCl. The acidliberated was diluted to 1 litre. The normality of acid solution will be [molecular weight of complex = 266.5]

3. (a) Arrange the following compounds in order of increasing molar coductivity(a) K[Co(NH3)2(NO2)4] (b) [Cr(NH3)3(NO2)3] (c) [Cr(NH3)5(NO2)]3[Co(NO2)6]2(d) Mg[Cr(NH3)(NO2)5](b) Deduce the value of x in the formulae of following complexes(i) Mo(CO)x (b) HxCr(CO)5 (c) HxCo(CO)4

4. Calculate the EAN of central atom in the following complexes(a) [Cr(CO)6] ; (b) [Fe(CN)6]

4– ; (c) [Fe(CO)5] ; (d) [Co(NH3)6]3+

(e) [Ni(CO)4] ; (f) [Cu(CN)4]3– ; (g) [Pd(NH3)6]4+ ; (h) [PtCl6]

2–

(i) [Fe(NO)2(CO)2] ; (j) [Fe(C5H5)2] ; (k) [Fe(CN)6]3– ; (l) [Ni(NH3)6]

2+

(m) [PdCl4]2– ; (n) [Pt(NH3)4]

2+ ; (o) [Co(NH3)6]2+

SECTION (C) : BONDING IN COORDINATION COMPOUNDS(Crystal field theory)

1. [Co(NH3)6]3+ & [CoF6]3– both are complexes of Co(III), but [Co(NH3)6]3+ is diamagnetic which [CoF6]3– isparamagnetic with = 4.90 B.M. Explain.


FINAL LAP - 2019COORDINATION COMPOUND2. Predict the hybridisation and geometry of the following complexes

(a) [NiBr4]2– ; (b) [Fe(CN)6]

3– ; (c) [MnCl6]3– ; (d) [AuCl4]

–

(e) [Fe(H2O)6]2+ ; (f) [Pt(NH3)4]2+ ; (g) [Co(NCS)4]

2– ; (h) [Cu(en)2]2+

3. How would you account for the following :(a) [Fe(CN6]

3– is weakly paramagnetic while [Fe(CN6]4– is diamagnetic

(b) All the octahedral complexes of Ni2+ must be outer orbital complexes.(c) Cobalt (II) is stable in aqueous solution but in the presence of complexing reagents(strong fieldligands) it is readily oxidised.(d) [Ni(CO)4] is tetrahedral whereas [Ni(CN)4]2- & [Pt(NH3)4]2+ are square planar.

4. Arrange the following in increasing order as directed.(a) (a) [CoCl3 (NH3)3] , (b) [CoCl (NH3)5] Cl2 , (c) [Co(NH3)6] Cl3 , (d) [CoCl2 (NH3)4] Cl – Molar conductance(b) C, N, O, X (halogen) -(donar atoms) - Strength of ligands.(c) Br–, S2– , NO2

– , CO , H2O, CN– , NH3, NO3– - strength of ligands.

SECTION (D) : APPLICATIONS OF CRYSTAL FIELD THEORY(Color of complex, Magnetic moment of complex, Stability of complex)

1. for IrCl63– is 27600 cm–1 (a) What is the wavelength of maximum absorption? (b) What would you predict for

the magnetic behaviour and the color of this ion(assume crystal field splitting to be high if it is in ultra violetregion)?

2. (a) [Ti(H2O)6]3+ absorbs light of wavelength 5000 Å. Name one ligand which would form a titanium(III) complex

absorbing light of lower wavelength than 5000 Å and one ligand which would a complex absorbing light ofwavelength higher than 5000 Å.(b) Calculate the magnetic moments(spin only) of the following complexes(i) [PtCl6]

2– (ii) [Cr(CO)6] (iii) [Ir(NH3)6]3+ (iv) [Pd(en)2]

2+

3. Predict the magnetic behaviour of the following complexes(i) [Co(NH3)6]

3+ (ii) [Rh(NH3)6]3+ (iii) [CoF6]

3– (iv) [Mn(CN)6]3–

(v) [MnBr4]2–

SECTION (E) : ISOMERISM IN COORDINATION COMPOUNDS(Structural Isomerism, Stereoisomerism, Geometrical Isomerism, Optical Isomerism)

1. What type of isomers are the following :(i) [Mn SCN (CO)5] and [Mn NCS (CO)5](ii) [Co(en)3] [Cr(CN)6] and [Cr(en)3] [Co(CN)6](iii) [Co NO3 (NH3)5 ] SO4 and [Co SO4 (NH3)5] NO3

(iv) [Co Cl (H2O)3 (py)2]Cl2 and [CoCl2 (H2O)2(py)2 ] Cl.H2O

2. How many geometrical isomers are possible for each of the following complexes.(a) Pt (NH3)2(SCN)2 (b) [CoCl2Br2]

2– (tetrahedral) (c) Co(NH3)3 (NO2)3

(d) Pt(en)Cl2 (e) [Cr Br2 (en)2]+ (f) [Rh(en)3]

3+

3. Tell how many diastereoisomers are possible for each of the following complexes, and draw their structures:(a) [Cr(NH3)2Cl4]

– (b) [Co(NH3)5Br]2+ (c)[FeCl2(NCS)2]2–

(d) [PtCl2Br2]2– (e) [Pt(NH3)2(CN)2] (f) [Co(en)(SCN)4]

–

(g) [Cr(H2O)2(NH3)2Cl2]+ (h) [Ru(NH3)3I3]

4. The octahedral complex [Rh(NO2) (SCN) (en)2]+ can exist in a total number of isomeric forms including

stereoisomers :



SECTION (F) : ORGANOMETALLIC COMPOUNDS

1. Draw the structures of the following metal carbonyls(a) [V(CO)6] (b) [Cr(CO)6] (c) [Mn2(CO)10](d) [Fe(CO)5] (e) [Co2(CO)8] (f) [Ni(CO)4] (g) [Fe2(CO)9]


EXERCISE - 2

SECTION (A) : GENERAL INTRODUCTION OF COMPLEX SALTS AND DEFINITIONS TO BE USED :

1.(a) Ethylene diamine is an example of a .......... ligand :(A) monodentate (B) bidentate (C) tridentate (D) hexadentate

(b) The donor sites of (EDTA)4– are(A) O atoms only (B) N atoms only(C) Two N atoms and four O atoms (D) Three N atoms and three O atoms

2.(a) Some salts although containing two different metallic elements give test for one of them in solution. Suchsalts are :(A) Complex salt (B) Double salt (C) Normal salt (D) None

(b) All ligands are :(A) Lewis acids (B) Lewis bases (C) neutral (D) none

3.(a) The oxidation state of Mo in its oxo-complex species [Mo2O4(C2H4)2(H2O)2]2– is(A) +2 (B) +3 (C) +4 (D) +5

(b) Co-ordination number of platinum in [Pt(NH3)4Cl2]++ ion is:(A) 4 (B) 2 (C) 8 (D) 6

(c) Which of the following is copper () compond :(A) [Cu(H2O)4]

2+ (B) [Cu(CN)4]3– (C) [Cu(NH3)4]

++ (D) All of these

4.(a) Oxidation state of cobalt in the complex [Co(NO2)6]3– is :(A) + 2 (B) + 3 (C) + 1 (D) +2 and + 3

(b) In the complex [Co(en)2Cl2]Br, the co-ordination number and oxidation state of cobalt are :(A) 6 and +3 (B) 3 and +3 (C) 4 and +2 (D) 6 and +1

(c) What is the charge on the complex [Cr(C2O4)2(H2O)2] formed by Cr() :(A) +3 (B) +1 (C) +2 (D) –1

SECTION (B) : NOMENCLATURE OF COORDINATION COMPOUNDS

1. The correct IUPAC name of the complex:

C = N

OH

OHH3C

C = NH3C

••

••CoCl2 is :

(A) Dichloro(dimethylglyoxime)cobalt(II) (B) Bis(dimethyglyoxime)dichlorocobalt(II)(C) Dimethylglyoximecobalt(II) chloride (D) Dichlorobis(dimethylglyoxime-N,N)-cobalt(II)


FINAL LAP - 2019COORDINATION COMPOUND2.(a) A complex cation is formed by Pt (in same oxidation state) with ligands (in proper number so that

coordination number of Pt becomes six). Which of the following can be its correct IUPAC name :(A) Diammineethylenediaminedithiocyanato-S-platinum (II) ion(B) Diammineethylenediaminedithiocyanato-S-platinate (IV) ion(C) Diammineethylenediaminedithiocyanato-S-platinum (IV) ion(D) Diamminebis (ethylenediamine) dithiocyanate-S- platinum (IV) ion

(b) Which of the following names is impossible :(A) Potassium tetrafluorooxochromate (VI) (B) Barium tetrafluorobromate (III)(C) Dichlorobis (urea) copper (II) (D) All are impossible.

3.(a) The formula of sodium nitroprusside is(A) Na4[Fe(CN)5NOS] (B) Na2[Fe(CN)5NO+] (C) NaFe[Fe(CN)6] (D) Na2[Fe(CN)6NO2]

(b) In sodium nitroprusside, the oxidation number, co-ordination number and EAN of iron are respectively(A) +3, 6, 36 (B) +2, 6, 36 (C) +3, 3, 36 (D) 6, +3, 35

(c) In Tollen’s reagent, the oxidation number, co-ordination number and effective atomic number of central metalion are respectively [atomic number of Ag - 47](A) +1, 2, 50 (B) +1, 2, 51 (C) 2, +1, 50 (D) +1, 1, 50

(d) The formula of the complex tris (ethylene diamine) cobalt (III) sulphate is :(A) [Co(en)2SO4] (B) [Co(en)3SO4] (C) [Co(en)3]2SO4] (D) [Co(en)3]2(SO4)3

4.(a) Which of the following pairs of name and formula of complexes, is not correct :(A) Tetramminecopper(II) sulphate............. [Cu(NH3)4]SO4(B) Diamminesilver(I) chloride ................ [Ag(NH3)2]Cl(C) Potassium hexacyanoferrate (III) ............... K4[Fe(CN)6](D) Potassium amminepentachloroplatinate (IV) ................. K[PtCl5(NH3)]

(b) The correct IUPAC name for the compound [Co(NH3)4CI(ONO)]Cl is :(A) Tetraamminechloronitrito–N–cobalt(III) chloride(B) Chloronitrito–O–tetraamminecobalt(II) chloride(C) Dichloronitrito–O–tetraamminecobalt (III)(D) Tetraamminechloronitrito–O–cobalt(III) chloride

(c) The hypothetical complex chlorodiaquatriamminecobalt(III) chloride can be represented as :(A) [CoCl(NH3)3(H2O)2]Cl2 (B) [Co(NH3)3(H2OCl3](C) [Co(NH3)3(H2O)2Cl] (D) [Co(NH3)3(H2O)3]Cl3 ]

SECTION (C) : BONDING IN COORDINATION COMPOUNDS(Initial bonding theories and EAN rule, Valence bond theory)

1.(a) EAN of a metal carbonyl M(CO)x is 36. If atomic number of metal M is 26, what is the value of x :(A) 4 (B) 8 (C) 5 (D) 6

(b) The effective atomic number of Co(CO)4 is 35 and hence is less stable. It attains stability by(A) oxidation of Co (B) reduction of Co (C) dimerization (D) tetramerization

2.(a) A compound is made by mixing cobalt (III) nitrite and potassium nitrite solutions in the ratio of 1 : 3. Theaqueous solution of the compound showed 4 particles per molecule whereas molar conductivity reveals thepresence of six electrical charges. The formula of the compound is(A) Co(NO2)3 . 2KNO2 (B) Co(NO2)3 . 3KNO2 (C) K3[Co(NO2)6] (D) K[Co(NO2)4]

(b) Which of the following will exhibit maximum ionic conductivity?(A) K4 [Fe(CN6] (B) [Co(NH3)6] Cl3 (C) [Cu(NH3)4] Cl2 (D) [Ni (CO)4]

(c) Which of the following shows maximum molar conductance :(A) [Co(NH3)6]Cl3 (B) [Co(NH3)3Cl3] (C) [Co(NH3)4 Cl2] Cl (D) [Co(NH3)5Cl]Cl2

(d) A co-ordination complex has the formula PtCl4.2KCl. Electrical conductance measurements indicatethe presence of three ion in one formula unit. Treatment with AgNO3 produces no ppt. of AgCl. What isthe co-ordination number of Pt in this complex :(A) 5 (B) 6 (C) 4 (D) 3


FINAL LAP - 2019COORDINATION COMPOUND3.(a) The complex [Cr(H2O)4Br2]Cl gives the test for :

(A) Br– (B) Cl– (C) Cr3+ (D) Br– and Cl– both

(b) Which of the following complexes produces three moles of silver chloride when its one mole is treatedwith excess of silver nitrate :(A) [Cr(H2O)3Cl3] (B) [Cr(H2O)4Cl2]Cl (C) [Cr(H2O)5Cl]Cl2 (D) [Cr(H2O)6]Cl3

(c) The number of chloride ions which would be precipitated when the complex PtCl4.4NH3 is treated withsilver nitrate is(CN = 6):(A) Four (B) One (C) Three (D) Two

(d) The number of ions per mole of the complex CoCl3.5NH3 in aqueous solution will be(CN = 6) :(A) Four (B) Nine (C) Three (D) Two

4.(a) The complex CoCl3.3NH3 on ionization gives (CN = 6):(A) No Cl– ions (B) 3 Cl – ions (C) 2 Cl– ions (D) 1 Cl– ions

(b) The chloride ion is detected by the formation of a white precipitate of AgCl on addition of aqueousAgNO3 solution and by the dissolution of the precipitate on addition of excess ammonia solution. AgCldissolves in aqueous ammonia due to the formation of water soluble :(A) [Ag (NH4)2]

+ (B) [Ag (NH3)2]+ (C) [Ag (NH2)2]

– (D) [Ag (OH)2]–

(c) Conc. H2SO4 will not dehydrate the following complex:(A) [Cr(H2O)5Cl]Cl2.H2O (B) [Cr(H2O)4Cl2]Cl.2H2O(C) [Cr(H2O)6]Cl3 (D) All of these.

(d) On adding AgNO3 solution to a solution of [Pt(NH3)3Cl3]Cl, the percentage of total chloride ion precipitatedis:(A) 100 (B) 75 (C) 50 (D) 25

5.(a) A coordination compound of cobalt has the molecular formula containing five ammonia molecules, onenitro group and two chlorine atoms for one cobalt atom. One mole of this compound produces threemoles of ions in an aqueous solution. The aqueous solution on treatment with an excess of AgNO3gives two moles of AgCl as a precipitate. The formula of this complex would be(A) [Co(NH3)4(NO2)Cl] [NH3Cl] (B) [Co(NH3)5Cl] [Cl NO2](C) [Co(NH3)5(NO2)] Cl2 (D) [Co (NH3)5] [(NO2)2Cl2]

(b) One mole of the complex compound [Co (NH3)5 Cl3] gives 3 moles of ions on dissolution in water. Onemole of the same complex reacts with two moles of AgNO3 solution to yield two moles of AgCl(s), Thestructure of the complex is(A) [Co(NH3)4Cl] Cl2. NH3 (B) [Co(NH3)5 Cl] Cl2(C) [Co(NH3)3Cl] . 2NH3 (D) [Co(NH3)4 Cl2] Cl. NH3

6. CoCl3.4H2O is an anhydrous binary solute hence its Werner’s representation is(CN = 6) :

(A) (B) (C) (D) None

SECTION (D) : BONDING IN COORDINATION COMPOUNDS(Crystal field theory)

1.(a) Which statement is incorrect ?

(A) Ni(CO)4 _____ Tetrahedral, paramagnetic (B) Ni(CN)4 ]

2– _____ Square planar, diamagnetic(C) Ni(CO)4

_____ Tetrahedral, diamagnetic (D) [NiCl4]2–

_____ Tetrahedral, paramagnetic

(b) The complex, [Ni(CN)4]2–, has :

(A) linear structure (B) tetrahedral structure(C) square planar structure (D) octahedral structure


FINAL LAP - 2019COORDINATION COMPOUND (c) The complex [Pt(NH3)4]

2+ has ..... structure :(A) square planar (B) tetrahedral (C) pyramidal (D) pentagonal

(d) What is the shape of Fe(CO)5 molecule ? Given that its dipole moment = 0.(A) Tetrahedral (B) Octahedral(C) Trigonal bipyramidal (D) Square pyramidal

2.(a) The number of unpaired electrons in d6, low spin, octahedral complex is :(A) 4 (B) 2 (C) 1 (D) 0

(b) Maximum paramagnetism in 3d-series is shown by(A) Mn (B) Co (C) Ni (D) Fe

(c) The number of d-electrons of Cr(Z = 24) in [Cr(H2O)6]3+ ion :(A) 2 (B) 3 (C) 4 (D) 5

3.(a) Low spin complex is formed by :(A) sp3d2 hybridization (B) sp3d hybridization(C) d2sp3 hybridization (D) sp3 hybridization

(b) Which of the following is a high spin complex:(A) [Co(NH3)6]3+ (B) [Fe(CN)6]4– (C) [Ni(CN)4]

2– (D) [FeF6]3–

(c) Which has maximum paramagnetic nature :(A) [Cu(H2O)4]

2+ (B) [Cu(NH3)4]2+ (C) [Mn(H2O)6]2+ (D) [Fe(CN)6]

4–

(d) The number of unpaired electrons present in complex ion [FeF6]3- is :(A) 5 (B) 4 (C) 6 (D) 0

4. The crystal field splitting energy for octahedral complex (o) and that for tetrahedral complex (t ) are related as

(A) t = 94

0 (B) t = 0.5 o (C) t = 0.33 o (D) t = 49

0

5. Which of the following complexes has a geometry different from others :(A) [Ni Cl4]

2– (B) Ni (CO)4 (C) [Ni(CN)4]2– (D) [Zn(NH3)4]

++

SECTION (E) : APPLICATIONS OF CRYSTAL FIELD THEORY(Color of complex, Magnetic moment of complex, Stability of complex)

1.(a) All the metal ions contains t2g6 eg

0 configuration. Which of the following complex will be paramagnetic-(A) [FeCl(CN)4(O2)]

4- (B) K4[Fe(CN)6] (C) [Co(NH3)6]Cl3 (D) [Fe(CN)5(O2)]-5

(b) Maximum paramagnetism in 3d-series is shown by(A) Mn (B) Co (C) Ni (D) Fe

(c) The compound which does not show paramagnetism :(A) [Cu(NH3)4Cl2 ] (B) [Ag(NH3)2]Cl (C) NO (D) NO2

(d) Among the following ions, which one has the highest paramagnetism?(A) [Cr(H2O)6]3+ (B) [Fe(H2O)6]2+ (C) [Cu(H2O)6]2+ (D) [Zn(H2O)6]2+

2. [Sc(H2O)6]3+ ion is :(A) Coloured and paramagnetic (B) Colourless and paramagnetic(C) Colourless and diamagnetic (D) Coloured and octahedral

3. Amongst Ni(CO)4, [Ni(CN)4]2– and NiCI42–

(A) Ni(CO)4 and NiCI42– are diamagnetic and [Ni(CN)4]2– is paramagnetic(B) NiCI42– and [Ni(CN)4]2– are diamagnetic and Ni(CO)4 is paramagnetic(C) Ni(CO)4 and [Ni(CN)4]2– are diamagnetic and NiCI42– is paramagnetic(D) Ni(CO)4 is diamagnetic and, NiCI42– and [Ni(CN)4]2– are paramagnetic



4. In complexes more stability is shown by(A) [Fe(H2O)6]3+ (B) [Fe(CN)6]3– (C) [Fe(C2O4)3]3– (D) [Fe(Cl)6]3–

SECTION (F) : ISOMERISM IN COORDINATION COMPOUNDS1.(a) Which of the following cannot show linkage isomerism?

(A) 2NO (B) SCN– (C) CN– (D) NH3

(b) The complexes [Pt(NH3)4] [Pt Cl6] and [Pt(NH3)4 Cl2] [Pt Cl4] are(A) linkage isomers (B) optical isomers(C) co-ordination isomers (D) ionisation isomers

(c) [Co(NH3)5NO2]Cl2 and [Co(NH3)5ONO]Cl2 are related to each other as :(A) geometrical isomers (B) linkage isomers(C) coordination isomers (D) ionisation isomers

2. The number of geometrical isomer of [Co(NH3)3(NO3)3] are :(A) 0 (B) 2 (C) 3 (D) 4

3. Geometrical isomerism is found in coordination compounds having coordination number :(A) 2 (B) 3 (C) 4 (tetrahedral) (D) 6

4. Cis-trans isomerism is found in square planar complexes of molecular formula ('a' and 'b' are monodentateligands) :(A) Ma4 (B) Ma3b (C) Ma2b2 (D) Mab3

5. Which of the following octahedral complex does not show geometrical isomerism (A and B are monodentateligands) :(A) [MA3B3] (B) [MA4B2] (C) [MA5B] (D) [MA2B4]

ADVANCE OBJECTIVE QUESTIONS

EXERCISE - 3

1. Which of the following statements are true (or) false -(i) [Cr(NH3)6][Cr(CN)6] and [Cr(NH3)4(CN)2] [Cr(NH3)2(CN)4] are coordination isomers(ii) [Cr(py)2(H2O)2Cl2]Cl and [Cr(py)2(H2O)Cl3]H2O are ligand isomers(iii) [Pt(NH3)4Br2]Cl2 and [Pt(NH3)4Cl2]Br2 are linkage isomers(iv) cis platin exhibits geometrical isomerism(A) TTFT (B) FTFT (C) TTFF (D) TFFT

2. In (a) [Co(H2O)4]2+ , (b) [CoCl4]

2– and (c) [Co(DMG)2] complexes :(i) a, b are paramagnetic & c is diamagnetic in nature(ii) a & b has magnetic moment greater than c(iii) a, c has tetrahedral structure and b has square planar structure(iv) In a, b there is one unpaired electron and in c it has 3 unpaired electrons(A) FTFT (B) FFTT (C) TFTF (D) FTFF

3. For the reaction Ni2+ + 4NH3 [Ni(NH3)4]2+at equilibrium, if the solution contains 1.6 × 10–4% of nickel in

the free state, And the concentration of NH3 at equilibrium is 0.5 M. Then the instability constant of thecomplex will be approximately equal to :(A) 1.0 × 10–5 (B) 1.5 × 10–16 (C) 1.0 × 10–7 (D) 1.5 × 10–17

4. EDTA is used for the estimation of(A) Na+ and K+ ions (B) Halide ions (C) Cu2+ and Ag+ ions (D) Ca2+ and Mg2+ ions


FINAL LAP - 2019COORDINATION COMPOUND5. If NO reacts with [Cr(CO)6] how many CO groups can be replaced by NO :

(A) all the 6 CO groups are replaced by 6 NO groups(B) all the 4 CO groups are replaced by 6 NO groups(C) all the 2 CO groups are replaced by 3 NO groups(D) all the 6 CO groups are replaced by 4 NO groups

6. [(NH ) Co — O — O — Co(NH ) ]3 5 3 5 +4 [(NH ) Co — O — O — Co(NH ) ]3 5 3 5 +5[S2O8]oxidise

2–

GreenBrownThe magnetic moment of green complex is 1.7 BM & for brown complex magnetic moment is zero.(O – O) is same in all respect in both the complexes.The O. S. of Co in brown complex & green complex respectively are –(A) III II & IV III (B) III III & III IV(C) III III & III II (D) III IV & III III

7. Which of the following isomers of [M(NH3)2Cl2] would react with silver oxalate (Ag2C2O4):

(A) (B) (C) Both (D) None

8. Which of the following pair of complexes have the same EAN of the central metal atoms/ions?(A) [Cu (NH3)4] SO4 and K4[Fe(CN)6] (B) K4[Fe(CN)6] and [Co(NH3)6] Cl3(C) K3 [Cr (C2O4)3] and [Ni(CO)4] (D) all of the above

9. The complex K4 [Zn (CN)4 (O2)2] is oxidised into K2 [Zn (CN)4 (O2)2] , then which of the following is/arecorrect ?(A) Zn (II) is oxidised into Zn (IV) (B) Paramagnetic moment decreases(C) O – O bond length increases (D) Paramagnetic moment increases

10. All the following complexes show decrease in their weights when placed in a magnetic balance thenthe group of complexes having tetrahedral geometry is :I Ni (CO)4 II K [AgF4] III Na2 [Zn (CN)4]IV K2 [PtCl4] V [RhCl (PPh3)3](A) II , III , V (B) I , II , III (C) I , III , IV (D) none of these

11. Wilkinson’s catalyst react with H2 to form an octahedral complex in which Rh (Z = 45) has the following

electronic configuration in the ligand field , 2,2,2g2t , 0,0

ge .

Then which of the following is correct about this new complex ?(A) It is diamagnetic(B) Its IUPAC name is chlorotris(triphenylphosphine)rhodium (I)(C) Hybridisation of Rh (I) is sp3d2 (D) It is a paramagnetic complex

12. The complex [Fe(H2O)5NO]2+ is formed in the brown ring test for nitrates when freshly prepared FeSO4

solution is added to aqueous solution of NO3– followed by addition of conc. H2SO4. Select correct statement

about this complex(A) Hybridisation of iron is d2sp3. (B) Iron & nitrosyl has +1 oxidation state(C) It has magnetic moment of 3.87 B. M. confirming three unpaired electrons in Fe(D) all the above are correct statements



13.

In both the complexes Co have t2g6eg

0 configuration. The B. E. of (O — O) in X & Y is -(A) B. E. of (O — O) in Y < B. E. of (O — O) in X(B) B. E. of (O — O) in X < B E. of (O — O) in Y(C) B. E. of (O — O) in X = B. E. of (O — O) in Y(D) B. E. of (O — O) in X & B. E. of (O — O) in Y can’t be comparable

SECTION (B) : ONE OR MORE THAN ONE CORRECT CHOICE

1. In which of the following are the chemical formula and the name correctly matched ?(A) K[Pt(NH3)Cl5] – potassium amminepentachloroplatinate (IV)(B) [Ag(CN)2]– – dicyanoargentate (I) ion(C) K3[Cr(C2O4)3] – potassium trioxalatochromate (III)(D) Na2[Ni (EDTA)] – Sodium ethylenediaminetetraacetonickel(I)

2. In which of the following does the central atom exhibit an oxidation state of +2 ?(A) K2[Ni(CN)4] (B) K3[Fe(CN)6] (C) [Fe(C2O4)3]3– (D) [Cu(NH3)4]

2+

3. Which of the following will produce a white precipitate upon reacting with AgNO3 ?(A) [Co(NH3)6]Cl3 (B) [Co(NH3)3Cl3] (C) K2 [Pt(en)2Cl2] (D) [Fe(en)3]Cl3

4. Which are correct statements ?(A) [Ag(NH3)2]

+ is linear with sp hybridised Ag+ ion.(B) NiCl4

2–, VO43– and MnO4

– have tetrahedral geometry.(C) [Cu(NH3)4]2+, [Pt(NH3)4]2+ and [Ni(CN)4]2– have dsp2 hybridisation of the metal ion(D) Fe(CO)5 have bipyramidal structure with dsp3 hybridised iron.

5. Which of the following is/are inner orbital complex(es) as well as dimagentic in nature.(A) [Zn(NH3)6]

2+ (B) [Ni(NH3)6]2+ (C) [Cr(NH3)6]3+ (D) [Co(NH3)6]

3+

6. Which of the following is/are correct about [Cu(NH3)4]SO4(A) It is a square planar complex. (B) It is paramagentic with one unpaired in the d-subshell.(C) It gives white ppt with BaCl2 (D) Its aqueous solution does not conduct electricity.

7. Which of the following isomerisms is/are shown by the complex [CoCl2(OH)2(NH3)2 ]Br ?(A) Ionization (B) Linkage (C) Geometrical (D) optical

8. Which of the following complexes have tetrahedral shape?(A) [Cu(NH3)4]2+ (B) [Ni(CO)4] (C) [NiCl4]2– (D) [Zn(NH3)4]

2+

9. Which of the following is/are paramagentic(A) [Fe(CN)6]4– (B) [Ni(CO)4] (C) [Ni(CN)4]

2– (D) [CoF6]3–

10. Co-ordination number of Cr in CrCl3.5H2O is six. The volume of 0.1 N AgNO3 needed to ppt. the chlorinein outer sphere in 200 ml of 0.01 M solution of the complex is/are:(A) 140 ml (B) 40 ml (C) 80 ml (D) 20 ml


FINAL LAP - 2019COORDINATION COMPOUND11. Three arrangements are shown for the complex [Co(en) (NH3)2 Cl2]+. Pick up the wrong statement.

(A) I and II are geometrical isomers (B) II and III are optical isomers(C) I and III are optical isomers (D) II and III are geometrical isomers



EXERCISE - 1

SECTION (A) :

1. (a) Hexaamminecobalt(III) chloride (b) Pentaammineiodorhodium(III) iodide(c) [Fe(CO)5], Pentacarbonyliron(0)(d) [Fe(C2O4)3]3–, Trioxalatoferrate(III) OR Tris(oxalato)ferrate(III)(e) [Cu(NH3)4]SO4, Tetraamminecopper(II) sulphate(f) Na[Cr(OH)4], Sodium tetraaquachromium(III)(g) Co(gly)3, Triglycinatocobalt(III) OR Tris(glycinato)cobalt(III)(h) [Fe(H2O)5(NCS)]2+, Pentaaquathiocyanato–N–iron(III)(i) K2[HgI4], Potassium tetraiodomercurate(II)(j) Co[Hg(SCN)4], Cobalt(II) tetrathiocyanato–S–mercurate(II)(k) Fe4[Fe(CN)6]3, Iron(III) hexacyanoferrate(II)(l) K3[Co(ONO)6], Potassium hexanitrito–O–cobaltate(III)(m) [Ni(dmg)2], Bis(dimethylglyoximato)nickel(II)(n) K2[PtCl6], Potassium hexachloroplatinate(IV)(o) Na2[Fe(CN)5NO+], Sodium pentacyanonitrosoniumferrate(II)(p) [Fe(H2O)5(NO+)]SO4, Pentaaquanitrosoniumiron(I) sulphate(q) Fe3[Fe(CN)6]2, Iron(II) hexacyanoferrate(III)(r) [Cu(CN)4]3–, Tetracyanocuperate(I)(s) [Cd(CN)4]2–, Tetracyanocadmate(II)(t) (NH4)2[PtCl6], Ammonium hexachloroplatinate(IV)

2. Name the following compounds

(a) [Co(en)2Br(ONO)]+1 Bromobis(ethylenediamine)nitrito–O–cobalt(III)

(b) [Co(NH3)6] [Co(ONO)6] Hexaamminecobalt(III) hexanitrito–O–cobaltate(III)

(c) [Co(NH3)5(CO3)]Cl Pentaamminecarbonatocobalt(III) chloride

(d) [Pt(NH3)4Cl2] [PtCl4] Tetraamminedichloroplatinum(IV) tetrachloroplatinate(II)

(e) [Co(en)3]2(SO4)3 Tris(ethylenediamine)cobalt(III) sulphate

(f) [Cr(PPh3)(CO)5] Pentacarbonyltriphenylphosphinechromium(0)

(g) [(CO)5Mn-Mn(CO)5] Decacarbonyldimanganese(0)

(h) K[PtCl3(-C2H4)] Potassium tricholoro( 2–ethylene)platinate(II)

(i) Cr(-C6H6)2 Bis(6–benzene)chromium(0)(j) [NH(CH3)3] [WCl(CO)5] Trimethylammonium Chloropentacarbonyltugnstate(0)(k) [Co(NH3)4(OH2)2][BF4]3 Tetraamminediaquacobalt(III) tetrafluoroborate(III)(l) Na4[Cu6(S2O3)5] Sodium pentakis(thiosulphato)hexacuperate(I)(m) Ba[Zr(OH)2(ONO)2(ox)] Barium dihydroxodinitrito–O–oxalatozirconate(IV)(n) [Co(NH3)6][Co(C2O4)3] Hexaamminecobalt(III) trioxalatocobaltate(III)

3. (a) diamminetriaquahydroxochromium(III) nitrate [Cr(OH)(H2O)3(NH3)2](NO3)2

(b) tetrakis(pyridine)platinum(II) tetraphenylborate(III) [Pt(Py)4] [B(ph)4]2

(c) dibromotetracarbonyliron(II) [Fe(Br)2(CO)4]



(d) ammonium diamminetetrakis(isothiocyanato)chromate(III). (NH4)[Cr(SCN)4(NH3)2](e) Pentaamminedinitrogenruthenium(II) chloride [Ru(NH3)5N2]Cl2(f) Bis(cyclopentadienyl)iron(II) [Fe(5–C5H5)2](g) Barium dihydroxodinitrito-O-oxalatozirconate(IV) Ba[Zr(OH)2(ONO)2(ox)](h) Tetrapyridineplatinum(II) tetrachloronickelate(II) [Pt(py)4][NiCl4]

SECTION (B) :

1. (a) – iv, (b) – viii, (c) – i, (d) – vii,(e) – iii, (f) – v, (g) – ii, (h) – vi

2. 0.0075

3. (a) b < a < d < c (b) (i) 6 (ii) 2 (iii) 1

4. (a) 36 (b) 36 (c) 36 (d) 36(e) 36 (f) 36 (g) 54 (h) 86(i) 36 (j) 36 (k) 35 (l) 38(m) 52 (n) 84 (o) 37

SECTION (C) :

1. Since ammonia is a strong field ligand so can pair up the electrons of Co(III), so will form an inner d-orbitalcomplex having zero magnetic moment while fluoride being a weak field ligand can not pair up electrons andforms outer d-complex with higher magnetic moment.

2. (a) [NiBr4]2– sp3, tetrahedral (b) [Fe(CN)6]

3– d2sp3, octahedral

(c) [MnCl6]3– sp3d2, octahedral (d) [AuCl4]

– dsp2, square planar

(e) [Fe(H2O)6]2+ sp3d2, octahedral (f) [Pt(NH3)4]

2+ dsp2, square planar

(g) [Co(NCS)4]2– dsp2, square planar (h) [Cu(en)2]

2+ dsp2, square planar

3. (a) In the complex [Fe(CN)6]3– the iron is in +3 oxidation state having d5 configuration, so even after

pairing due to strong field cyanide ligands one electron will remain unpaired and hence it is weaklyparamagnetic. While in the complex [Fe(CN)6]

4– iron is in +2 oxidation state and having d6 configuration, so after pairing due to strong field cyanide ligand no unpaired electron remains, so is diamagnetic.

(b) Octahedral complexes requires d2sp3 hybridisation for being inner d–orbital complexes, which willnot be available in d8 configuration of Ni2+, hence all complexes are outer d–orbital complexes.

(c) Co2+ has d7 configuration and only strong field ligands can excite the last electron of the d orbital tohigher orbitals and can form more stable inner d–orbital complexes with d2sp3 hybridisation.

(d) In [Ni(CO)4], Ni is in 0 oxidation state so has 3d84s2 configuration which after pairing due to strongfield CO ligands will become 3d10, and hence no d orbitals are empty, it can only undergo sp3

hybridisation leading to tetrahedral geometry. While in other given complexes Ni is in 2+ oxidationstate so will form dsp2 complexes.

4. (A) a < d < b < c (B) X < O < N < C (C) Br– < S2– < NO3– < H2O < NH3 < NO2

– < CN– < CO

SECTION (D) :

1. diamagnetic, colorless

2. (a) CN– , F– (b) (i) 0 (ii) 0 (iii) 0 (iv) 0

3. (i) 0 (ii) 0 (iii) 4 (iv) 2 (v) 5


FINAL LAP - 2019COORDINATION COMPOUNDSECTION (E) :

1. (i) Linkage (ii) Coordination (iii) Ionisation (iv) Hydrate

2. (a) Two (b) None (c) Two (d) None (e) Two (f) None

3. (a) 2 (b) none (c) none (d) 2 (e) 2 (f) none(g) 5 (h) 2

4.

(1) NO2 / SCN (5) NO2 / SCN (9)(2) ONO / SCN (6) ONO / SCN (10)(3) NO2 / NCS (7) NO2 / NCS (11) (4) ONO / NCS (8) ONO / NCS (12)

SECTION (F) :

1. (a)

V

CO

CO

CO

CO

OC

OC

(b)

Cr

CO

CO

CO

CO

OC

OC

(c) Mn

OC

Mn

OC

OC

COCO

CO CO

CO

COCO

(d) Fe

CO

CO

CO

OC

OC

(e) Co

OC

OC

CO CO CO

COCo

COCO

OR

OC

OCCO

COCO

OC

Co

CO

CO

Co

(f)Ni

CO

COOC CO

(g)

OC

OCCO

COCO

OC

Fe Fe

COCO

CO



EXERCISE - 2SECTION (A) :

1.(a) B (b) C 2.(a) A (b) B

3.(a) B (b) D (c) B 4.(a) B (b) A (c) D

SECTION (B) :

1. A 2.(a) C (b) A

3.(a) B (b) B (c) A (d) D 4.(a) C (b) D (c) A

SECTION (C) :

1.(a) C (b) C 2.(a) C (b) A (c) A (d) B

3.(a) B (b) D (c) D (d) C

4.(a) A (b) B (c) C (d) D

5.(a) C (b) B 6. C

SECTION (D) :

1.(a) A (b) C (c) A (d) C 2.(a) D (b) A (c) B

3.(a) C (b) D (c) C (d) A 4. A 5. C

SECTION (E) :

1.(a) A (b) A (c) B (d) B 2. C 3. C 4. C

SECTION (F) :

1.(a) D (b) C (c) B 2. B 3. D 4. C 5. C


1. D 2. D 3. C 4. D 5. D 6. B 7. A

8. B 9. D 10. D 11. A 12. D 13. B

SECTION (B) :

1. ABC 2. AD 3. AD 4. ABCD 5. D 6. AC 7. ACD

8. BCD 9. D 10. BD 11. BCD


FINAL LAP - 2019S - BLOCK ELEMENT S - BLOCK ELEMENT


EXERCISE - 11. The hydroxides and carbonates of sodium and potassium are easily soluble while the corresponding salts of

magnesium and calcium are sparingly soluble in water. Explain.

2. Why do alkali metals form unipositive ions and impart characteristic colours to flame?

3. How would you explain ?(i) BeO is insoluble but BeSO4 is soluble in water.(ii) BaO is soluble but BaSO4 is insoluble in water.

4. How is BeCl2 prepared ? What is its structure in solid state and vapour state.

5. Pallets of potassium hydroxide become wet when exposed to air.

6. Which is the strongest reducing agent among alkali metals?

7. Why are alkali metals difficult to be reduced ?.

8. Why are alkali metals (except Li) kept in kerosene?

9. In aqueous solution , Li+ ions has the least mobility among alkali metals . Why?

10. Alkali metal ions are colourless as well as diamagnetic. Explain.

11. Lithium forms monoxide, sodium gives peroxide while the rest of the alkali metals form superoxide. Explain

12. Does Mg impart charateristic colour to the flame?

13. E1 value of Mg is more than that of Na while it’s E2 value is less. Explain.

14. What happens when(i) Sodium metal is dropped in water ?(ii) Sodium metal is heated in free supply of air ?(iii) Sodium peroxide dissolves in water ?

15. LiF is least soluble among the fluorides of alkali metals. Explain.

16. Alkali metals are soft and can be cut with the help of a knife.

17. What is quick lime, slaked lime and lime water ?

18. The crystalline salts of alkaline earth metals contain more molecules of water of crystallisation than thecorresponding salts of alkali metals . Explain.

19. Why is LiF almost insoluble in water where as LiCl is soluble not only in water but also in acetone ?

20. When an alkali metal dissolves in liquid ammonia the solution acquires different colours. Explain the reasonsfor this type of colour change.

21. Lithium is the only alkali metal to form a nitride directly. Why ?

22. LiI is more soluble than KI in ethanol.

23. Name the process used in the manufacture of Na2CO3 .

24. Sodium is prepared by electrolytic method and not by chemical method.

25. Why does a piece of burning Mg ribbon continues to burn in SO2? Give the name of product.

26. Arrange the following in decreasing order of ionic character . CaCl2, BeCl2 , BaCl2 , MgCl2, SrCl2.

27. Arrange the following in decreasing order of solubility in water .(i) Be (OH)2, Ca(OH)2, Ba(OH)2 , Sr(OH)2 ; (ii) BaSO4 , MgSO4, CaSO4 , SrSO4

28. Beryllium chloride fumes in air . Why ?

29. Explain why alkaline earth metals are harder than alkali metals ?

30. Hydrated magnesium chloride cannot be dehydrated by heating .Why ?

31. Contrast the action of heat on the following and explain your answer.(i) Na2CO3 and CaCO3 ; (ii) MgCl2 .6H2O and CaCl2.6H2O ;(iii) Ca(NO3)2 and NaNO3


FINAL LAP - 2019S - BLOCK ELEMENT


EXERCISE - 2SECTION (A) : ONLY ONE ANSWER IS CORRECT :1. Alkali metals are not characterised by :

(A) good conductor of heat and electricity (B) high oxidation potentials(C) high melting points (D) solubility in liquid ammonia

2. The substance X belonging to A group gives a pale violet colour in flame test, X is :(A) NaCl (B) LiCl (C) KCl (D) None of these

3. Which of the following increases in magnitude as the atomic number of alkali metals increases?(A) electronegativity (B) first ionisation potential(C) ionic radius (D) melting point

4. Sodium has, as compared to potassium :(A) less electronegativity (B) more ionisation potential(C) larger atomic radius (D) lower melting point

5. The metallic lustre exhibited by sodium is explained by :(A) diffusion of sodium ions (B) oscillation of mobile valence electrons(C) existence of free protons (D) existence of body centred cubic lattice

6. Which of the following has the highest melting point?(A) NaCl (B) NaF (C) NaBr (D) Na

7. In view of their ionisation energies, the alkali metals are :(A) weak oxidising agents (B) strong reducing agents(C) strong oxidising agents (D) weak reducing agents

8. Which of the following has lowest melting point?(A) Li (B) Na (C) K (D) Cs

9. On dissolving large amount of sodium metal in liquid NH3 at low temperature, which one of the followingdoes not occur ?(A) Blue coloured solution is obtained(B) Na+ ions are formed in the solution(C) Liquid NH3 solution becomes good conductor of electricity(D) Liquid NH3 solution remains diamagnetic

10. A solution of sodium in liquid ammonia is strongly reducing due to the presence of(A) sodium atoms (B) sodium hydride (C) sodium amide (D) solvated electrons

11. Which salt on heating does not give brown coloured gas ?(A) LiNO3 (B) KNO3 (C) Pb(NO3)2 (D) AgNO3

12. Which of the following can not decompose on heating to give CO2?(A) Li2CO3 (B) Na2CO3 (C) KHCO3 (D) BaCO3

13. Peroxide ion is present in(A) MgO (B) CaO (C) Li2O (D) BaO2

14. Equimolar amounts of which of the following will give maximum hydrogen ion concentration?(A) NaOH (B) KOH (C) LiOH (D) RbOH


FINAL LAP - 2019S - BLOCK ELEMENT15. The deep colour produced when iodine is dissolved in a solution of potassium iodide is caused by the

presence of:

(A) 2 (B) – (C) 3 (D) 2

16. Match the compounds /metal in (X) with their uses in (Y) :X Y

A. liquid sodium metal breathing apparatus in submarineB. potassium stearate explosiveC. potassium nitrate coolant in nuclear reactionD. potassium superoxide V soft soap

A B C D A B C D(A) V (B) V (C) V (D) V

17. Which does not exist in solid state.(A) NaHCO3 (B) NaHSO3 (C) LiHCO3 (D) CaCO3

18. Sodium metal can be stored under :(A) benzene (B) kerosene (C) alcohol (D) water

19. Sodium burns in dry air to give :(A) Na2O (B) Na2O2 (C) NaO2 (D) Na3N

20. LiAIH4 is used as :(A) an oxidising agent (B) a reducing agent (C) a mordant (D) a water softener

21. Sodium sulphate is soluble in water whereas barium sulphate is sparingly soluble because :(A) the hydration energy of sodium sulphate is more than its lattice energy(B) the lattice energy of barium sulphate is less than its hydration energy(C) the lattice energy has no role to play in solubility(D) the hydration energy of sodium sulphate is less than its lattice energy

22. Strong reducing agent of alkali metals is :(A) Li (B) Na (C) K (D) Cs

23. In certain matters, lithium differs from other alkali metals, the main reason for this is :(A) small size of lithium atom and Li+ (B) extremely high electropositivity of Li(C) greater hardness of Li (D) hydration of Li+ ion

24. Which reacts directly with nitrogen to form nitride ?(A) Na (B) Li (C) K (D) Rb

25. Compounds of alkaline earth metals are less soluble in water than the corresponding alkali metal saltsdue to:(A) their high ionisation energy (B) their low electronegativity(C) their low hydration energy (D) their high lattice energy

26. Which of the following is different from other three oxides ?(A) MgO (B) SnO (C) ZnO (D) PbO

27. BeF2 is soluble in water, whereas, the fluorides of other alkaline earth metals are insoluble because of :(A) ionic nature of BeF2(B) greater hydration energy of Be2+ ion as compared to lattice energy(C) covalent nature of BeF2(D) none of these


FINAL LAP - 2019S - BLOCK ELEMENT28. Among LiCl, RbCl, BeCl2, MgCl2 the compounds with greatest and least ionic character respectively

are :(A) LiCl, RbCl (B) RbCl, BeCl2 (C) RbCl, MgCl2 (D) MgCl2, BeCl2

29. Following are the ionisation potential values of :(I1) 899 kJ mol–1, (2) 1757 kJ mol–1 , (3) 15000 kJ mol–1

(A) Na (B) K (C) Be (D) Ne

30. Which is not s–block element :(A) [Ar]4s2 3d10 4p6 5s1 (B) 1s2 2s2 2p1 (C) 1s2 2s1` 2p1 (D) [He] 2s2 2p6 3s1

31. The alkaline earth metals are :(A) Na and K (B) Mg and Ca (C) Cu and Ag (D) Al and Fe

32. A fire work gave bright crimson light. It probably contained a salt of :(A) Ca (B) Sr (C) Ba (D) Mg

33. The most electropositive amongst the alkaline earth metals is :(A) Be (B) Mg (C) Ca (D) Ba

34. A chloride dissolves appreciably in cold water. When placed on a platinum wire in Bunsen flame, no distinctivecolour is noticed. What one is cation ?(A) Mg2+ (B) Ba2+ (C) Pb2+ (D) Ca2+

35. Alkaline earth metal salts are :(A) paramagnetic (B) diamagnetic (C) ferromagnetic (D) all

36. The first ionisation energies of alkaline earth metal are higher than those of the alkali metals. This is because:(A) there is increase in the nuclear charge of the alkaline earth metal(B) there is decrease in the nuclear charge of the alkaline earth metal(C) there is no change in the nuclear charge(D) none of these

37. The first ionisation potential (eV) of Be and B respectively are :(A) 8.29, 9.32 (B) 9.32, 9.32 (C) 8.29, 8.29 (D) 9.32, 8.29

38. Which of the following is incorrect ?(A) Mg burns in air releasing dazzling light rich in UV rays.(B) CaCl2.6H2O when mixed with ice gives freezing mixture.(C) Mg cannot form complexes.(D) Be can form complexes due to its very small size.

39. Among the alkaline earth metals, the element forming predominantly covalent compound is :(A) Ba (B) Sr (C) Ca (D) Be

40. The set represnting the correct order of first ionisation potential is :(A) K > Na > Li (B) Be > Mg > Ca (C) B > C > N (D) Ge > Si > C

41. Which of the following has maximum ionisation energy ?

(A) Ba Ba+ + e– (B) Be Be+ + e–

(C) Ca Ca2+ + 2e– (D) Mg Mg2+ + 2e–


FINAL LAP - 2019S - BLOCK ELEMENT42. Which of the following salts on heating gives a mixture of two gases ?

(A) Ba(NO3)2 (B) NaNO3 (C) KNO3 (D) RbNO3

43. Amongst the following hydroxides, the one which has the lowest value of Ksp at ordinary temperature is :(A) Mg(OH)2 (B) Ca(OH)2 (C) Ba(OH)2 (D) Be(OH)2

44. Lithopone is a mixture of(A) barium sulphate and zinc sulphide (B) barium sulphide and zinc sulphide(C) calcium sulphate and zinc sulphide (D) calcium sulphide and zinc sulphide

45. A metal M readily forms water soluble sulphate MSO4, water insoluble hydroxide M (OH)2 and oxide MOwhich becomes inert on heating. The hydroxide is soluble in NaOH. The M is :(A) Be (B) Mg (C) Ca (D) Sr

46. A piece of magnesium ribbon was heated to redness in an atmosphere of nitrogen and on cooling waterwas added, the gas evolved was :(A) ammonia (B) hydrogen (C) nitrogen (D) oxygen

47. Which of the following metal carbonate is decomposed on heating ?(A) Na2CO3 (B) MgCO3 (C) K2CO3 (D) Rb2CO3

48. The hydration energy of Mg2+ ions is higher than that of :(A) Al3+ (B) Be2+ (C) Na+ (D) N

49. When magnesium burns in air, compounds of magnesium formed are magnesium oxide and :(A) Mg3N2 (B) MgCO3 (C) Mg(NO3)2 (D) Mg(NO2)2

50. The right order of the solubility of sulphates of alkaline earth metals is :(A) Be > Ca > Mg > Ba > Sr (B) Mg > Be > Ba > Ca > Sr(C) Be > Mg > Ca > Sr > Ba (D) Mg > Ca > Ba > Be > Sr

51. Na and Li are placed in dry air. We get :(A) NaOH, Na2O, Li2O (B) Na2O, Li2O (C) Na2O, Li2O, Li3N, NH3 (D) Na2O, Li3N, Li2O

52. Which of the following has lowest thermal stability ?(A) Li2CO3 (B) Na2CO3 (C) K2CO3 (D) Rb2CO3

53. Which of the following is the strongest base ?(A) Ca(OH)2 (B) Sr(OH)2 (C) Ba(OH)2 (D) Mg(OH)2

54. The name oxone is given to(A) ozone (B) sodium peroxide (C) sodium oxide (D) sodamide

55. If NaOH is added to an aqueous solution of Zn2+ ions, a white precipitate appears and on adding excess ofNaOH, the precipitate dissolves. In the solution, zinc exists in the :(A) Anionic part (B) Cationic part(C) both in anionic and cationic part (D) colloidal form

56. Zinc reacts with excess of caustic soda to form :(A) Zn(OH)2 (B) ZnO (C) Na2ZnO2 (D) Zn(OH)2.ZnCO3


FINAL LAP - 2019S - BLOCK ELEMENT57. Sodium carbonate can be manufactured by Solvay’s process but potassium carbonate cannot be prepared

because:(A) K2CO3 is more soluble (B) K2CO3 is less soluble(C) KHCO3 is more soluble than NaHCO3 (D) KHCO3 is less soluble than NaHCO3

58. Plaster of Paris hardens by :(A) giving off CO2 (B) utilising water (C) changing into CaCO3 (D) giving out water

59. A compound X on heating gives a colourless gas. The residue is dissolved in water to obtained Y.Excess CO2 is bubbled through aqueous solution of Y, Z is formed. Z on gently heating gives back X.The compound X is:(A) CaCO3 (B) Na2CO3 (C) Ca(HCO3)2 (D) K2CO3

60. Intermediate formed by heating microcosmic salt and which froms coloured bead with coloured cation is :(A) NH3 (B) H3PO3 (C) NaPO3 (D) H2O

61. When SO2 gas is passed into aqueous Na2CO3, product formed is :(A) NaHSO4 (B) Na2 SO4 (C) NaHSO3 (D) ALL

62. The reaction of sodium thiosulphate with 2 gives :(A) sodium sulphide (B) sodium sulphite (C) sodium sulphate (D) sodium tetrathionate

63. Electrolysis of fused NaCl will give :(A) Na (B) NaOH (C) NaClO (D) NaClO3

64. The principal products obtained on heating iodine with concentrated caustic soda solution :(A) NaIO + NaI (B) NaIO + NaIO3 (C) NaIO3 + NaI (D) NaIO4 + NaI

65. Washing soda has the formula :(A) Na2CO3 (B) Na2CO3.H2O (C) Na2CO3.7H2O (D) Na2CO3.10H2O

66. Sodium carbonate on heating gives :(A) CO2 (B) water vapours(C) carbon dioxide + water vapour (D) none of these

67. Which one of the following electrolyte is used in Down’s process of extracting sodium metal ?(A) NaCl + KCl + KF (B) NaCl (C) NaOH + KCl + KF (D) NaCl + NaOH

68. Plaster of Paris is :(A) CaSO4 (B) CaSO4. H2O (C) 2CaSO4.H2O (D) CaSO4.2H2O

69. If CO2 is passed in excess into lime water, the milkiness first formed disappears due to :(A) reversal of original reaction (B) formation of volatile calcium bicarbonate(C) formation of soluble calcium bicarbonate (D) formation of soluble magnesium hydroxide

70. Molecular formula of Glauber’s salt is :(A) MgSO4. 7H2O (B) CuSO4. 5H2O (C) Na2SO4. 10H2O (D) FeSO4. 7H2O

71. The colour of iodine solution is discharged by shaking it with aqueous solution of :(A) H2SO4 (B) sodium sulphide (C) sodium sulphate (D) sodium thiosulphate


FINAL LAP - 2019S - BLOCK ELEMENT72. Sodium carbonate is prepared by:

(A) Solvay’s process (B) Kolbe’s process (C) Contact process (D) Nessler’s process

73. Na2S2O3.5H2O is used in photography to :(A) reduce AgBr to metallic Ag(B) remove reduced Ag(C) remove undecomposed AgBr as a soluble complex(D) convert metallic Ag to silver salt

74. Calcium is extracted by the electrolysis of :(A) Fused mixture of CaCl2 and CaF2 (B) CaCl2 solution(C) Fused mixture of CaCl2 and NaF (D) Ca3(PO4)2 solution

75. At high temperature, nitrogen combines with CaC2 to give :(A) calcium cyanide (B) calcium cyanamide (C) Calcium carbonate (D) calcium nitride

76. Identify the correct statement :(A) Gypsum contains a lower percentage of calcium than Plaster of Paris(B) Gypsum is obtained by heating Plaster of Paris(C) Plaster of Paris is obtained by hydration of gypsum(D) Plaster of Paris is obtained by partial oxidation of gypsum

77. Of the following the commonly used in the laboratory dessicator is :(A) Na2CO3 (B) CaCl2 (C) NaCl (D) CaCO3

78. K2O can be prepared by(A) burning metallic potassium in air. (B) passing oxygen in liquid ammonia.(C) reducing KNO3 with metallic potassium. (D) reducing K2SO4 with porous graphite.

79. Which of the following statement is not correct ?(A) KOH is a stronger alkali than NaOH.(B) Milk of magnesia is aqueous suspension of Mg(OH)2.(C) MgO is a refractory material used for lining electrical furnaces.(D) Mg(OH)2 precipitates on heating hydrated MgCl2.

80. Anhydrone is(A) NaClO3 (B) NaClO4 (C) KClO3 (D) Mg(ClO4)2

81. What are the products formed when an aqueous solution of magnesium bicarbonate is boiled:(A) MgCO3, H2O, CO2 (B) Mg(HCO3)2, H2O(C) Mg(OH)2, H2O (D) Mg, CO2, H2O

82. When hydated MgCl2. 6H2O is strongly heated :(A) MgO is formed (B) Mg(OH)2 is formed(C) Mg(OH)Cl is formed (D) anhydrous MgCl2 is formed

83. Anhydrous MgCl2 may be obtained by heating MgCl2. 6H2O(A) until it fuses (B) with lime(C) with coal (D) in a current of dry HCl

84. Carnallite is :(A) KCl (B) LiAl(SiO3)2 (C) MgCl2.6H2O (D) KCl.MgCl2.6H2O

85. The mixture of MgCl2 and MgO is called :(A) sorel cement (B) mixed salt (C) portland cement (D) magnesium oxychloride


FINAL LAP - 2019S - BLOCK ELEMENTSECTION (B) : ONE OR MORE THAN ONE CORRECT ANSWER

86. Alkali metals are characterised by(A) Good conductor of heat and electricity (B) High oxidation potentials(C) High melting points (D) Solubility in liquid ammonia.

87. Which is/are not correct configuration of s–block elements :(A) (Ar) 3d10 4s2 (B) (Ar) 3d10 4s1 (C) (Ar) 4s2 (D) (Ar) 4s1

88. Highly pure dilute solution of sodium in liquid ammonia(A) Shows blue colour (B) Exhibits electrical conductivity(C) Produces sodium amide (D) Products hydrogen gas

89. Nitrate can be converted into metal oxide on heating in case of :(A) Li (B) Na (C) Mg (D) None of these

90. Select correct statement (s) :(A) Li2CO3 is only sparingly soluble in water and no LiHCO3 has been isolated.(B) K2CO3 cannot be made by a method similar to the ammonia – soda process.(C) Li2CO3 and MgCO3 both are thermally stable.(D) Na2CO3 . NaHCO3 . 2H2O is a mineral called trona.

91. Select correct statement (s) :(A) stability of peroxides and superoxides of alkali metals increases with increase in size of the metal ion(B) increase in stability in (A) is due to stabilisation of large anions by larger cations through lattice energyeffects.(C) the low solubility of LiF is due to its high lattice energy whereas low solubility of CsI is due to smallerhydration energy .(D) NaOH does not form hydrated salt.

92. Flame test is not given by(A) Be (B) Mg (C) Ca (D) Sr

93. Be and Al resemble in :(A) both become passive on reaction with HNO3 due to formation of oxide layer(B) their chlorides are Lewis acids(C) chlorides exist in polymeric form(D) hydroxides are soluble in alkali as well as in acid

94. Going down to A group, following properties decrease :(A) solubility of sulphates in H2O (B) hydration energy(C) thermal stability of carbonates (D) ionic radius in water.

95. Which is/are true statements ?(A) The heats of hydration of the dipositive alkaline earth metal ions decrease with an increase in their

ionic size.(B) Hydration of alkali metal ion is less than that of A.(C) Alkaline earth metal ions, because of their much larger charge to size ratio, exert a much stronger

Electrostatic attraction on the oxygen of water molecule surrounding them.(D) None

96. In water :(A) temporary hardness is due to the bicarbonates of Ca2+ and Mg2+

(B) permanent hardness is due to chlorides and sulphates of Ca2+ and Mg2+

(C) hardness can be removed by adding phosphates.(D) none is correct.


FINAL LAP - 2019S - BLOCK ELEMENT97. Sodium sulphate is soluble in water but barium sulphate is sparingly soluble because :

(A) the hydration energy of Na2SO4 is more than its lattice energy(B) the lattice energy of BaSO4 is more than its hydration energy(C) the lattice energy has no role to play in solubility(D) the lattice energy of Na2SO4 is more than its hydration energy

98. Be and Al have following resemblance due to diagonal relationship :(A) have nearly equal electronegativity (B) form amphoteric oxides(C) have same charge/radius ratio (D) both form dimeric halides

99. The pairs of compound which cannot exist together in aqueous solution are(A) NaH2 PO4 and Na2HPO4 (B) Na2 CO3 and NaHCO3(C) NaOH and NaH2 PO4 (D) NaHCO3 and NaOH.


FINAL LAP - 2019S - BLOCK ELEMENT

EXERCISE - 11. Alkaline earth metal cations possess high lattice energy due to their small size and higher charge. The

hydration energy can not compensate for the energy required to break the lattice in these compounds.

2. As removal of IInd electron from inert gas configuration requires very high energy, therefore, they formunipositive ions. As IE1 of these metals are low, the excitation of electrons can be done by providing the lessenergy. This much of energy can be given by Bunsen flame.

3. (i) Be2+ & O2– smaller in size & thus higher lattice energy and lattice energy is greater than hydration energyin BeO where as in BeSO4 lattice energy is less due to bigger sulphate ion and is soluble.(ii) In BaSO4 lattice energy is greater than hydration energy while in BaO lattice energy is smaller thanhydration energy.

4. BeO + C + Cl2 K800600 BeCl2 + CO ; In vapour state it exists as linear molecule where as in solid it has

polymeric strucutre.

5. Highly deliquescent absorbs moisture from air and their surface become wet.

6. Lithium

7. Because of low IE1 & high electro positive character they are themselves strong reducing agent.

8. Highly reactive elements as their IE1 values are low.

9. Because of smallest size of Li+, it has higher degree of hydration and has bigger hydrated ions. Hence Li+

has least mobility.

10. In unipositive ions all electrons are paired.

11. Smaller cation is stabilised by smaller anion & bigger cation is stabilised by bigger anion.

12. No, as its IE1 is very high & therefore requires higher energy for excitation of electron. This much of energycan not be provided by Bunsen flame.

13. Removal of IInd electron from Na+ takes place from inert gas configuration.

14. (i) Na + H2O NaOH + 1/2H2

(ii) 2Na + O2 Na2O2

(iii) Na2O2 + H2O 2NaOH + 1/2O2

15. Li+ being smallest has highest polarising power, hence most covalent in character. So least soluble in H2O.

16. Due to large atomic size & only one valence electron per atom, alkali metals have weak metallic bonds asinter particle forces.

17. Quick lime is CaO, slaked lime is Ca(OH)2 and lime water is a clear solution of calcium hydroxide in water.

18. Higher positive charge density on alkaline earth metal cations attract more no. of water molceules leading tohigher degree of hydration.

19. Li+ & F– are smaller & possess higher lattice energy therefore almost insoluble in water.LiCl has ionic as wellas covalent character.

20. Refer text.

21. It being strongest reducing agent converts N2 into N3– .

22. ‘Like dissolves like’ LiI more covalent while KI is more ionic.

23. Ammonia soda process or Solvey process.

24. As Na itself is a strong reducing agent & more electro positive element.

ANSWER KEY


FINAL LAP - 2019S - BLOCK ELEMENT25. Mg acts as strong reducing agent & reduces SO2 to S thus utilises its oxygen for burning.

2Mg + SO2 2MgO + S

26. BaCl2 > SrCl2 > CaCl2 > MgCl2 > BeCl2.

27. (i) Ba(OH)2 > Sr(OH)2 > Ca(OH)2 > Be(OH)2 ; (ii) MgSO4 > CaSO4 > SrSO4 > BaSO4

28. Due to the formation of HCl on hydrolysisBeCl2 + H2O Be(OH)2 + 2HCl

29. Due to greater nuclear charge and small size, there is greater interparticle forces & thus pack more tightly insolid lattice.

30. Being covalent gets hydrolysed forming MgO.

MgCl2. 6H2O MgO + 2HCl + 5H2O

31. (i) Na2CO3 No change (stable to heat ; CaCO3 CaO + CO2

(ii) MgCl2. 6H2O MgO + 2HCl + 5H2O ; CaCl2. 6H2O CaCl2 + 6H2O

(iii) Ca(NO3)2 CaO + 2NO2 + 1/2O2 ; NaNO3 NaNO2 + 1/2O2

EXERCISE - 2SECTION (A, B)

Q.No. 1 2 3 4 5 6 7 8 9 10Ans. C C C B B B B D D D

Q.No. 11 12 13 14 15 16 17 18 19 20Ans. B B D C C B C B B B

Q.No. 21 22 23 24 25 26 27 28 29 30Ans. A A A B D A B B C B

Q.No. 31 32 33 34 35 36 37 38 39 40Ans. B B D A B A D C D B

Q.No. 41 42 43 44 45 46 47 48 49 50Ans. D A D A A A B C A A

Q.No. 51 52 53 54 55 56 57 58 59 60Ans. D A C B A C C B A C

Q.No. 61 62 63 64 65 66 67 68 69 70Ans. D D A C D D A C C C

Q.No. 71 72 73 74 75 76 77 78 79 80Ans. D A C A B A B C D D

Q.No. 81 82 83 84 85 86 87 88 89 90Ans. A A D D A ABD AB AB AC ABD

Q.No. 91 92 93 94 95 96 97 98 99Ans. ABC AB ABCD ABD ABC ABC AB ABCD CD


FINAL LAP - 2019P - BLOCK ELEMENT


EXERCISE - 1 ONLY ONE ANSWER IS CORRECTGroup 13th

1. Which of the following facts regarding boron and silicon is not true :(A) Boron and silicon are semiconductors.(B) Boron and silicon form halides which are not hydrolysed.(C) Boron and silicon react with magnesium to form magnesium boride and magnesium silicide which

are decomposed by acids to give volatile borane and silane, respectively.(D) Both boron and silicon react with alkali to form borates and silicates containing BO4 and SiO4

tetrahedral units, respectively.

2. B3+ cannot exist in aqueous solution becuase of its :(A) Strong reducing ability. (B) Strong oxidizing ability.(C) Small size and large charge. (D) Large size and small charge.

3. The product obtained in the reaction of diborane with excess of ammonia is :(A) B2H6. NH3 (B) B2H6. 2NH3 (C) (BN)x (D) Borazine

4. In the following reaction :B (OH)3 + H2O [B(OH)4]

– + H+

(A) B(OH)3 is a Lewis acid (B) B(OH)3 is a Lewis base(C) B(OH)3 is amphoteric (D) none is correct

5. The decrease stability of higher oxidation state in p–block with increasing atomic number is due to :(A) Increase in bond energy as going down the group(B) Energy required to unpair ns2 – electrons is not compensated by the energy released in forming the twoadditional bonds(C) Both are correct(D) None is correct.

6. Pure boron is best prepared by(A) Heating B2O3 with H2 (B) Heating B2O3 with Na or K(C) Heating KBF4 with Na or K (D) Heating BBr3 with H2 in presence of a catalyst

7. Water softener is :(A) Borax (B) Zeolite(C) Both (A) and (B) (D) None of these

8. Which of the following statements regarding ortho boric acid (H3BO3) is false ?(A) It acts as a weak monobasic acid (B) It is soluble in hot water(C) It has a planar structure (D) It acts as a tribasic acid

9. When orthoboric acid is heated to red heat, the residue is :(A) Boron (B) Boric oxide (C) Metaboric acid (D) Pyroboric acid

10. BF3 on hydrolysis forms :(A) H3BO3 (B) HBF4 (C) Both (A) and (B) (D) None of these

11. From B2H6 all the following can be prepared except :(A) H3BO3 (B) NaBH4 (C) B2(CH3)6 (D) B2O3

12. Boron nitride has the structure of the type :(A) Both diamond and graphite (B) Graphite(C) Diamond (D) NaCl

13. On passing CO2 into aqueous solution containing Al3+ :(A) Al2(CO3)3 is formed (B) Al(OH)3 is precipitated(C) Al2O3 is formed (D) Collodial Al(OH)3 is formed


FINAL LAP - 2019P - BLOCK ELEMENT14. Alum is found to contain hydrated monovalent cation [M(H2O)6]

+ , trivalent cation [M(H2O)6]3+ and SO4

2– inthe ratio of :(A) 1 : 1 : 1 (B) 1 : 2 : 3 (C) 1 : 3 : 2 (D) 1 : 1 : 2

15. When orthoboric acid (H3BO3) is heated the residue left is:(A) Boron (B) Metaboric acid (C) Boric anhydride (D) Borax

16. Borax is:(A) Na2B4O7 (B) Na2B4O7.4H2O (C) Na2B4O7.7H2O (D) Na2B4O7.10H2O

17. Borax on heating with cobalt oxide forms a blue bead of:(A) Co(BO2)2 (B) CoBO2 (C) Co3(BO3)2 (D) Na3Co(BO3)2

18. The correct order of decreasing hardness of the follwing compound is:(A) Diamond > Borazone > Carborundum > Corundum(B) Borazone > Diamond > Carborunndum > Corundum(C) Corundum > Carborundum > Borazone > Diamond(D) None

19. Al dissolves in molten NaOH with the formation of:(A) Sodium aluminate (Na3AlO3) (B) Sodium metaluminate (NaAlO2)(C) Aluminium hydroxide (D) Alumina

20. Aqueous solution of potash alum is:(A) Alkaline (B) Acidic (C) Neutral (D) Soapy

21. Alumina is ......... in nature:(A) Acidic (B) Basic (C) Amphoteric (D) Neutral

22. The protective film of oxide on the surface of Al metal may be strengthened by:(A) Galvanizing (B) Cathodizing (C) Sheradizing (D) Anodizing

23. The borax bead is chemically:(A) B2O3 (B) Na2B4O7 (C) Na3BO3 (D) B2O3 + NaBO2

24. When Al is added to potassium hydroxide solution:(A) No reaction takes place (B) Oxygen is evolved(C) Water is produced (D) Hydrogen is evolved

25. Which reaction cannot give anhydrous AlCl3:(A) Heating of AlCl3.6H2O(B) Passing dry HCl over heated aluminium powder(C) Passing dry Cl2 over heated aluminium powder(D) Heating a mixture of alumina and coke in a current of dry Cl2

26. Alum is used by dyer of cloth:(A) For fire-proofing fabrics (B) As first aid for cuts(C) For softening hard water (D) As mordant

27. Stable compounds in +1 oxidation state is formed by:(A) B (B) Al (C) Ga (D) Tl

28. Aluminium vessels should not be washed with materials containing washing soda because:(A) Washing soda is expensive(B) Washing soda is easily decomposed(C) Washing soda reacts with aluminium to form soluble aluminate(D) Washing soda reacts with aluminium to form insoluble aluminium oxide


FINAL LAP - 2019P - BLOCK ELEMENT29. Aluminium is more reactive than iron. But aluminium is less easily corroded then iron because:

(A) Aluminium is a noble metal (B) Oxygen forms a protective oxide layer(C) Iron unergoes reaction easily with water (D) Iron forms both mono and divalent ions

30. The dissolution of Al(OH)3 by a solution of NaOH results in the formation of:(A) [Al(H2O)4(OH)]2+ (B) [Al(H2O)2(OH)4]- (C) [Al(H2O)3(OH)3] (D) [Al(H2O)6(OH)3]

31. Which mixed sulphate is not an alum:(A) K2SO4.Al2(SO4)3.24H2O (B) K2SO4.Cr2(SO4)3.24H2O(C) Na2SO4.Fe2(SO4)3.24H2O (D) CuSO4.Al2(SO4)3.24H2O

32. Which of the following is pseudo alum:(A) (NH4)2SO4.Fe(SO4)3.24H2O (B) K2SO4.Al2(SO4)3.24H2O(C) MnSO4.Al2(SO4)3.24H2O (D) None

33. Aluminium does not react with:(A) NaOH (B) HCl (C) N2 (D) HNO3

34. Borax bead test is responded by:(A) Divalent metals (B) Heavy metals(C) Light metals (D) Metal which forms coloured metaborates

35. When a solution of sodium hydroxide is added in excess to the solution of potash alum, we obtain:(A) A white precipitate (B) Bluish white precipitate(C) A clear solution (D) A crystalline mass

36. Which of the following is a gas (at 0°C) :(A) BF3 (B) BCl3 (C) BBr3 (D) BI3

37. Aluminium metal is corroded in coastal places near to the sea, beacause protective oxide film:(A) Is removed by sea water (B) Reacts with sea water(C) Is attacked by salt present in sea water (D) Reacts with sand particles

38. B2O3 is:(A) Ionic (B) Basic (C) Acidic (D) Amphoteric

39. On the addition of mineral acid to an aqueous solution of borax, the compound formed is:(A) Borodihydride (B) Orthoboric acid (C) Metaboric acid (D) Pyroboric acid

40. Pure H2S gas can be obtained by the action of water on:(A) CuS (B) FeS (C) Flower of sulphur (D) Al2S3

41. Which cannot be prepared by B2H6:(A) NaBH4 (B) H3BO3 (C) B2(CH3)6 (D) B2H6 . 2NH3

42. Which does not react with water:(A) B2S3 (B) B4C (C) Al4C3 (D) Al2S3

43. Diborane reacts with water to form:(A) HBO2 (B) H3BO3 (C) H3BO3 + H2 (D) H2


FINAL LAP - 2019P - BLOCK ELEMENT44. There are two H-bridge bonds in diborane molecule because there are:

(A) Only 12 electrons (B) 14 electrons(C) 2 elecrons less required for bonding (D) Two electrons more than required for bonding

45. Borax is prepared by treating colemanite with:(A) NaNO3 (B) NaCl (C) Na2CO3 (D) NaHCO3

46. An aqueous solution of BCl3 is:(A) Weak acid (B) Weak base (C) Neutral (D) Strong base

47. Boric acid is polymeric because of:(A) Its acidic nature (B) Presence of hydrogen bonds(C) Its monobasic nature (D) Its geometry

48. The bonds present in borazole are:(A) 12, 3 (B) 9, 6 (C) 6, 6 (D) 9, 9

49. Reactivity of borazole is greater than that of benzene because:(A) Borazole is non-polar compound (B) Borazole is polar compound(C) Borazole has electrons in it (D) Of localized electrons in it

50. Aqueous ammonia is used as a precipitating reagent for Al3+ ions as Al(OH)3 rather than aqueous NaOH,because:

(A) N 4H is a weak base (B) NaOH is a very strong base

(C) NaOH forms [Al(OH)4]- ions (D) NaOH forms [Al(OH)2]+ ions

51. BCl3 does not exist as dimer but BH3 exist as dimer (B2H6) because:(A) Chlorine is more electronegative than hydrogen(B) There is p-p back bonding in BCl3 but BH3 does not contain such multiple bonding(C) Large sized chlorine atoms do not fit in between the small boron atoms whereas small sized hydrogenatoms get fitted in between boron atoms(D) None of the above

52. An aqueous solution of borax is(A) netural (B) amphoteric (C) basic (D) acidic

53. Boric acid is polymeric due to(A) its acidic nature (B) the presence of hydrogen bonds(C) its monobasic nature (D) its geometry

54. Aqueous solution containing 1 mol of borax reacts with 2 mol of acids. This is because of :(A) formaiton of 2 mol of B(OH)3 only(B) formation of 2 mol of [B(OH)4]

– only(C) formation of 1 mol each of B(OH)3 and [B(OH)4]

–

(D) formation of 2 mol each of [B(OH)4]– and B(OH)3 , of which only [B(OH)4]

– reacts with acid

55. Borax is used as a buffer since :(A) Its aqueous solution contains equal amount of weak acid and its salt(B) It is easily available(C) Its aqueous solution contains equal amount of strong acid and its salt(D) Statement that borax is a buffer, is wrong


FINAL LAP - 2019P - BLOCK ELEMENTGroup 14th

56. Me2SiCl2 OH2 (A) oncondensati (B).The nature of product (B) may be(A) only linear polymers (B) cyclic products(C) (A) and (B) both (D) none of these

57. Diamond and graphite are(A) Isomers (B) Isotopes (C) Allotropes (D) None of the above

58. CO is isostructural with(A) HgCl2 (B) SnCl2 (C) C2H2 (D) NO2

59. HCl is added to the following oxides. Which will give H2O2?(A) MnO2 (B) PbO2 (C) BaO2 (D) NO2

60. Which of the following is a good conductor of electricity ?(A) diamond (B) graphite (C) coal (D) none

61. CO forms a voltile compound with(A) nickel (B) copper (C) sodium (D) aluminium

62. A colourless gas which burns with blue flame and reduces CuO to Cu is :(A) N2 (B) CO (C) CO2 (D) NO2

63. H2SO4 is not used for the preparation of CO2 from marble chips because :(A) it does not react (B) huge amount of heat is evolved(C) the reaction is vigorous(D) calcium sulphate is sparingly soluble and get deposited on marble chips and stops the reaction

64. Producer gas is the mixture of :(A) CO and N2 (B) CO and H2 (C) N2 and NH3 (D) CO, H2 and N2

65. If CO2 is passed in excess into lime water, the milkiness first formed disappears due to(A) reversal of the original reaction(B) formation of volatile calcium derivative(C) formation of water soluble calcium bicarbonate(D) the solution getting heated by exothermic reaction

66. When steam is passed through red hot coke :(A) CO2 and H2 are obtained (B) CO and N2 are formed(C) CO and H2 are obtained (D) petrol gas is obtained

67. Glass is soluble in(A) HF (B) H2SO4 (C) HClO4 (D) aqua-regia

68. Coal gas is a mixture of(A) CO and H2 (B) H2, saturated and unsaturated hydrocarbons, CO, CO2, N2 and O2(C) Saturated and unsaturated hydrocabons (D) CO, CO2 and CH4

69. Which of the following is not hydrolysed ?(A) CCl4 (B) SiCl4 (C) SnCl4 (D) PbCl4

70. Red lead is(A) PbO (B) PbO2 (C) Pb3O4 (D) Pb2O3



71. Which one of the oxides is netural ?(A) CO (B) SnO2 (C) ZnO (D) SiO2

72. The formula of white lead is(A) Pb(OH)2. PbCO3 (B) 2PbCO3.Pb(OH)2(C) Pb(OH)2. Pb(CH3COO)2 (D) PbCO3 . PbO

73. The butter of tin is represented by(A) SnCl2 . 5H2O (B) SnCl2 (C) SnCl4 (D) SnCl4 . 5H2O

74. The hydroxide of which metal ion is soluble in excess of sodium hydroxide solution(A) Fe3+ (B) Cr3+ (C) Sn3+ (D) Cu2+

75. Which compound is called sugar of lead ?(A) PbCl2 (B) Pb(NO3)2 (C) PbSO4 (D) Pb(CH3COO)2

76. The number and type of bonds between two carbon atoms in CaC2 are(A) one sigma and one pi bond (B) one sigma and two pi bonds(C) one sigma and one and a half pi bond (D) one sigma bond

77. Tin reacts with conc. HNO3 and gives(A) stannic nitrate (B) stannous nitrate (C) metastannic acid (D) none of sigma bond

78. CCl4 is inert towards hydrolysis but SiCl4 is readily hydrolysed because(A) carbon cannot expand its octet but silicon can expand its octet(B) ionisation potential of carbon is higher than silicon(C) carbon forms double and triple bonds(D) electronegativity of carbon is higher than that of silicon

79. Carborundum is the commercial name of(A) Al2O3 (B) SiC (C) CaCN2 (D) CaC2

80. Lead dissolves most readily in(A) acetic acid (B) sulphuic acid (C) nitric acid (D) hydrochloric acid

81. Softening of lead’ means(A) conversion of lead to PbO (B) conversion of lead to Pb3O4(C) removal of impurities (metallic) from lead(D) washing lead with HNO3 followed by a dil. alkali solution.

82. Which of the following is obtained on heating potassium ferrocyanide with H2SO4?(A) CO2 (B) CO (C) C2H2 (D) (CN)2

83. Inert form of carbon is(A) Diamond (B) Graphite (C) Coal (D) Charcoal

84. The carbide which gives propyne on hydrolysis is :(A) Al4C3 (B) CaC2 (C) Fe3C (D) Mg2C3

85. Which of the following reactions is not correct ?(A) CF4 + 2F– [CF6]2– (B) SiF4 + 2F– [SiF6]2–

(C) GeCl4 + 2Cl– [GeCl6]2– (D) SnCl4 + 2Cl– [SnCl6]2–


FINAL LAP - 2019P - BLOCK ELEMENT86. The ions present in Al4C3, CaC2 and Mg2C3 are respectively-

(A) C4–, C22–, C3

4– (B) C22–, C4–, C3

4– (C) C34–, C3

2–, C4– (D) C34–, C4–, C2

2–

87. Allylides are ionic carbides. They contains(A) C4– ions (B) C2 2– (C) C3

3– ions (D) C34– ions

88. The structural unit pesent in pyro sillicates is(A) Si3O9

6– (B) SiO44– (C) Si2O7

6– (D) (Si2O52–)n

89. Fire extinguishers contain a bottle of H2SO4 and :(A) CaCO3 (B) MgCO3 (C) NaHCO3 (D) any carbonate

90. Which substance is used as lubricant?(A) SnCl2 (B) SiO2 (C) graphite (D) quartz

91. CO is absorbed by(A) CHCl3 (B) pyrogallol(C) CCl4 (D) ammonical solution of copper (I) chloride

92. Thermodynamically the most stable form of carbon is(A) diamond (B) graphite (C) fullerenes (D) coal

93. Elements of group 14(A) exhibit oxidation state of +4 only (B) exhibit oxidation state of +2 and +4(C) form M–2 and M4+ ions (D) form M2+ and M4+ ions

94. Hot concentrated HNO3 converts graphite into :(A) Graphite oxide (B) Benzene hexacarboxylic acid(C) Both (A) and (B) (D) None of the above

95. Silicon reacts with hot solution of NaOH forming :(A) Si(OH)4 (B) Si(OH)2 (C) SiO2 (D) Na4SiO4

96. When a mixture of carbon monoxide and chlorine is exposed to sunlight the product formed is :

(A) Thionyl chloride (B) Phosgene(C) Phosphine (D) Carbon tetrachloride

97. CO2 in water behaves as :(A) Weak dibasic acid H2CO3 (B) Weak monobasic acid HO – CO2H(C) Weak diacid base CO(OH)2 (D) Weak monoacid base HO – CO2H

98. Methanides are :(A) Mg2C3 , Be2C, Al4C3 and CaC2 (B) Mg2C3 , Be2C and Al4C3(C) Be2C, Al4C3 and CaC2 (D) Be2C and Al4C3

99. Select incorrect statemen (s) :(A) Interstitial carbides are formed by metalloids like Si and B(B) Covalent carbides are formed by metalloids(C) CO and CN– both are fatal due to complex formation with Fe(III) present in blood(D) SiC is called carborundum

100. The oxide which is not a reducing agent is(A) CO2 (B) NO2 (C) SO2 (D) CIO2



101. In group 15, the melting points of the elements(A) increase regularly on moving down the group.(B) decrease regularly on moving down the group.(C) first decrease upto As and then increase to Bi(D) first increase form N to As and then decrease to Bi.

102. N2 molecule is very stable because(A) nitrogen is unreactive at ordinary temperatures(B) the two nitrogen atoms are linked together through a double bond(C) the two nitrogen atoms are linked together through a single bond(D) the bond dissociation energy of N N bond is very high

103. The H–M--H bond angle in the hydrides of group 15 elements follows the order(A) NH3 > PH3 > AsH3 > SbH3 (B) NH3 < PH3 < AsH3 < SbH3(C) NH3 < PH3 = AsH3 = SbH3 (D) PH3 > NH3 > AsH3 > SbH3

104. The thermal stability of the hydrides of group 15 follows the order(A) NH3 < PH3 < AsH3 < SbH3 < BiH3 (B) NH3 > PH3 > AsH3 > SbH3 > BiH3(C) PH3 > NH3 > AsH3 > SbH3 < BiH3 (D) AsH3 < PH3 > SbH3 > BiH3 > NH3

105. The hydrides of group 15 elements act as(A) Lewis acids (B) Lewis bases (C) both (D) none

106. The basic strength of the hydrides of goup 15 elements(A) decreases on moving down the group (B) increases on moving down the group(C) first decreases upto AsH3 and then increases (D) first increases upto AsH3 and then decreases

107. When NH3 is oxidised with excess NaOCl, the compound formed is(A) NCl3 (B) NH2OH (C) N3H (D) NO2

108. A gas is obtained on heating ammonium nitrate. The gas(A) causes laughter (B) brings tears to the eyes(C) is acidic in nature (D) basic in nature

109. The gas obtained on heating lead nitrate to 400ºC is(A) N2O (B) NO (C) NO2 (D) N2O5

110. Which of the following oxides is amphoteric in nature ?(A) N2O3 (B) P4O6 (C) Sb4O6 (D) Bi2O3

111. Which of the following acids is monobasic?(A) H3PO2 (B) H3PO4 (C) H4P2O7 (D) H4P2O6 .

112. Which of the following is (are) paramagnetic in nature?(A) NO (B) NO2 (C) N2O4 (D) A and B both

113. Which of the following compounds does give N2 on heating?(A) NH4NO2 (B) NH4NO3 (C) NaN3 (D) Both (A) and (C)


FINAL LAP - 2019P - BLOCK ELEMENT114. A mixture of alumina and coke is heated in a current of nitrogen to about 1800ºC and the product obtained is

treated with water. A gas is evolved. The gas is(A) N2 (B) N2O (C) NH3 (D) NO

115. When ammonia is oxidsed by oxygen in the presence of platinum at 800ºC, the gas obtained is(A) N2O (B) NO (C) NO2 (D) N2O5

116. NO2 can be prepared by heating(A) NH4NO3 (B) NaNO3 (C) Pb(NO3)2 (D) KNO3

117. Which of the following acids can form two types of salts?(A) Hyponitrous acid (B) Nitrous acid (C) Nitric acid (D) Pernitric acid

118. Nitric acid usually turns yellow on standing. This is due to(A) absorption of yellow wavelength (B) slow decomposition of HNO3 into NO2(C) its oxidation by atmospheric air (D) absorption of moisture by it

119. Nitric acid oxidises P into(A) PH3 (B) P2O5 (C) HPO3 (D) H3PO4

120. Which of the following metals does not dissolve in conc. HNO3?(A) Pb (B) Cu (C) Au (D) Hg

121. The geometry of the phosphorus molecule (P4) is(A) linear (B) angular (C) squar planar (D) tetrahedral

122. Which of the following is least reactive ?(A) White phosphorus (B) Yellow phosphorus(C) Red phosphorus (D) Black phosphorus

123. When P4O10 is dissolved in water, the acid formed finally is(A) H3PO2 (B) H3PO4 (C) H3PO3 (D) H4P2O7

124. Phosphoric acid on heating above 300ºC gives(A) hypophosphorus acid (B) orthophosphoric acid(C) metaphosphoric acid (D) phosphorous acid

125. Metaphosphoric acid exists in polymeric form and may have(A) a linear structure (B) a cyclic structure(C) both linear as well as cyclic structures (D) None

126. In the ostwald’s process, nitric acid is prepared by the catalytic oxidation of(A) N2 (B) NH3 (C) N2O5 (D) NO2

127. Red phosphorus can be prepared from white phosphorus by(A) adding red colour to white phosphorus(B) heating white phosphorus to red heat(C) heating white phosphorus with few crystals of iodine(D) dissolving white phosphorus in NaOH

128. .... is obtained when ammonium dichromate is heated(A) nitrogen (B) oxygen (C) ammonia (D) none


FINAL LAP - 2019P - BLOCK ELEMENT129. Superphosphate of lime is

(A) Ca3(PO4)2.CaSO4 (B) Ca(H2PO4)2(C) Ca(H2PO4)2.CaSO4 (D) Ca(H2PO4)2.H2O.2CaSO4.2H2O

130. A hydride of nitrogen which is acidic in nature :(A) N3H (B) N2H4 (C) NH3 (D) N4H4

131. Nitrolim is obtained by passing nitrogen over :(A) heated mixture of Al2O3 and carbon (B) carborundum(C) calcium carbide (D) heated aluminium

132. White phosphorus may be removed from red phosphorus by(A) sublimation (B) distillation(C) dissolving in CS2 (D) heating with an alkali solution

133. Which of the following will combine with Fe(II) ion to form a brown complex compound?(A) N2O (B) NO (C) N2O3 (D) NO2

134. Which of the following dibasic acids shows geometrical isomerism ?(A) Hyponitrous acid H2N2O2 (B) Maleic acid C4H4O4(C) Both (a) and (b) (D) None of the above

135. 1 mol each of H3PO2, H3PO3 and H3PO4 will neutralise x mole of NaOH, y mol of Ca(OH)2 and z mol ofAl(OH)3 (assuming all as strong electrolytes) respectively. x,y,z are in the ratio of :(A) 3 : 1 . 5 : 1 (B) 1 : 2 : 3 (C) 3 : 2 : 1 (D) 1 : 1 : 1

136. Glacial phosphoric acid is :(A) HPO3 (B) H3PO3 (C) H3PO4 (D) H4P2O7

137. Holme's signals can be given by using(A) CaC2 + CaCN2 (B) CaC2 + Ca3P2 (C) CaC2 + CaCO3 (D) Ca3P2 + CaCN2

138. Which is a set of acid salts and can react with base ?(A) NaH2PO2, Na2HPO3, NaH2PO4 (B) Na2HPO3, NaH2PO3, Na2HPO4(C) NaH2PO4, NaH2PO3, Na2HPO4 (D) All of these

139. NH3 can't be obtained by(A) heating of NH4NO3 or NH4NO2 (B) heating of NH4Cl or (NH4)2 CO3(C) heating of NH4NO3 with NaOH (D) reaction of AIN or Mg3N2 or CaCN2 with H2O

140. Red and white phosphorus will differ but not in :(A) smell (B) solubility in CHCl3(C) exhibiting phosphoresence (D) reaction with conc. HNO3

141. Choose correct statement(A) Superphosphate is [3Ca(H2PO4)2 + 7CaSO4] (B) Triple superphosphate is [10Ca(H2PO4)2](C) Both (a) and (b) are correct (D) None is correct

142. N2O (laughing gas) finds use in the following except :(A) as a propellant for whipped ice-cream (B) as an anaesthetic(C) for the preparation of N3H (D) as fuel for rockets


FINAL LAP - 2019P - BLOCK ELEMENT143. Select incorrect statement about N2O4 :

(A) It self ionises as NO+, NO3–

(B) N2O4 is paramagnetic(C) Substance containing NO+ is said to be acid and that containing NO3

– is said to be base(D) NO2 dimerises to N2O4 with disappearance in paramagnetism

144. Compound used in safety matches is(A) P4S3 (B) P4 (C) P2O5 (D) PCl3

145. The wrong statement about N2O is(A) It is nitrous oxide (B) It is least reactive oxide of nitrogen(C) It is not a linear molecule (D) It is known as laughing gas

146. The mixture of concentrated HCl and HNO3 made in 3 : 1 ratio contains :(A) CIO2 (B) NOCl (C) NCI3 (D) N2O4

147. The true statement for the acids of phosphorus. H3PO2 H3PO3 and H3PO4 is.(A) H3PO3 on heating does not disproportionate(B) All of them are reducing in nature(C) All of them are tribasic acids(D) The geometry of phosphorus is tetrahedral in all the three

148. Nitrogen is obtained by the thermal decomposition of :(A) NH4Cl (B) NH4NO3 (C) AgNO3 (D) None of these

149. The substance used as a fast drying agent in the laboratory is :(A) Na3 PO4 (B) P2O5 (C) charcoal (D) anhydrous calcium chloride

150. 4HNO3 + P4O10 4HPO3 + Xin the above reaction the product X is :(A) NO2 (B) N2O3 (C) N2O4 (D) N2O5

151. Cold solution of barium nitrite on mixing with sulphuric acid produces :(A) BaSO4 + HNO2 (B) BaSO4 + HNO3 (C) BaSO4 + NO2 (D) BaSO4 + N2 + O2

152. Following are neutral oxides except :(A) NO (B) N2O (C) CO (D) NO2

153. Pure N2 is prepared in the laboratory by heating a mixture of :(A) NH4Cl and NaOH (B) NH4OH and NaCl (C) NH4Cl and NaNO2 (D) NH4Cl and NaNO3

154. Substances burn more readily in N2O than in air because N2O :(A) is reactive at high temperature(B) dissociates to give O2 that supports combustion(C) the activation energy is increased on increasing temperature(D) acts as a catalyst

155. NH4Cl (s) is heated in test tube. Vapours are brought in contact with red litmus paper, which changes to blueand then to red. It is because of :(A) formation of NH4OH and HCl (B) formation of NH3 and HCl(C) greater diffusion of NH3 than HCl (D) greater diffusion of HCl than NH3


FINAL LAP - 2019P - BLOCK ELEMENT156. A gaseous substance dissolve in water giving a pale blue solution which decolourises KMnO4 and oxidised

KI to I2 .(A) N2O5 (B) NH3 (C) N2O3 (D) HNO3

157. In the preparation of red phosphorus from white phosphorus :(A) MnO2 is used as a catalyst (B) the white phosphorus is treated in an electric furnace(C) a little iodine is used as catayst in absence of air (D) the gas P4 is released

158. Compound A undergoes hydrolysis to produce a colourless gas with rotten fish smell. The gas gives a vortexring. The gas is :(A) PH3 (B) P2O3 (C) P2O5 (D) P2S5

159. A substance which gives a yellow precipitate when boiled with an excess of nitric acid and ammoniummolydate, and yellow precipitate with AgNO3 is :(A) orthophosphate (B) pyrophosphate (C) metaphosphate (D) hypophosphate

160. Calgon (sodium methphosphate) finds application as :(A) artificial jewel (B) paint (C) a resin (D) washing powder

161. Phosphorus trichloride, PCl3 undergoes, hydrolysis at room temperature to produce an oxoacid. It has theformula :(A) HPO3 (B) H3PO3 (C) H3PO4 (D) H3PO2

162. The high reactivity and low volatility of white phosphorous is due to :(A) tetrahedrally arranged P4 units (B) bond angle of 600 increases steric (strain) factor(C) weak van der Waals forces of attraction (D) both (B) and (C)

16th Group

163. The oxide which on strong heating gives oxygen is :(A) AgNO3 (B) BaO2 (C) Both (A) and (B) (D) Na2 O

164. In the reactionO3 + 2 + H2O (X) + O2

The compound (X) is(A) HO3 (B) H (C) HO4 (D) 2O5

165. When H2S is passed through acidified K2Cr2O7 solution, the solution turns,(A) Yellow (B) Blue (C) Green (D) White

166. Which one of the following gives mixture of SO2 and SO3 on heating ?(A) ZnSO4 (B) CuSO4 (C) Fe2 (SO4)3 (D) FeSO4

167. Which of the following statement is false.(A) An acidified solution of titanium salt gives yellow or orange colour with H2O2.(B) An acidified solution of K2Cr2O7 gives a bright blue coloured compound with H2O2 which is soluble inether.(C) Reaction of HCHO with H2O2 in presence of pyrogallol in alkaline solution liberates hydrogen gas(D) Anhydrous H2O2 is more stable and is kept in glass bottles.

168. The aqueous solution of hydrogen peroxide(A) converts blue litmus pink (B) converts blue litumus white(C) converts red litumus blue (D) None of these


FINAL LAP - 2019P - BLOCK ELEMENT169. Which is true about ozone ?

(A) It turns filter paper soaked in alcoholic benzidine to brown colour.(B) It is used for detecting the position of double bond in unsaturated organic compound.(C) It forms a solid 4O9 with dry iodine (2)(D) All of these

170. The following catalyst is used in the manufacturing of sulphuric acid by lead chamber process.(A) NO (B) NO2 (C) Pt (D) V2O5

171. The gas respectively absorbed by alkaline pyrogallol and oil of cinnamon is(A) O2, O3 (B) SO2, O3 (C) O3, CH4 (D) N2O, O3

172. Concentrated H2SO4 displaces hydrogen chloride from chlorides because :(A) it is stronger than hydrochloric acid. (B) HCl is a gas while H2SO4 is a liquid.(C) Sulphates are more soluble than chlorides (D) Sulphates are less soluble than chlorides

173. H2SO4 has very corrosive action on skin because :(A) It reacts with proteins(B) it acts as an oxidising agent(C) It acts as a dehydrating agent(D) It acts as a dehydrating agent and absorption of water is highly exothermic.

174. When H2S is passed through nitric acid and KMnO4 solution, the product formed is(A) H2SO4 (B) colloidal sulphur (C) SO2 (D) plastic sulphur

175. Which of the following hydrides of the oxygen family shows the lowets boiling point?(A) H2O (B) H2S (C) H2Se (D) H2Te

176. Alkaline K is oxidised by ozone to(A) potassium iodate (B) potassium periodate (C) both (A) and (B) (D) None of these

177. Which of the following reactions depict the oxidising behaviour of H2SO4 ?

(A) 2PCl5 + H2SO4 2POCl3 + 2HCl + SO2 Cl2

(B) 2NaOH + H2SO4 Na2SO4 + 2H2O

(C) NaCl + H2SO4 NaHSO4 + HCl

(D) 2H + H2SO4 2 + SO2 + 2H2O

178. Sulphur on oxidation with hot sulphuric acid gives :(A) SO3 (B) SO2 (C) H2SO3 (D) H2S2O3

179. Which of the following statement is true for sulphur dioxide?(A) it reacts with dry chlorine in absence of moisture to form sulphuryl chloride.(B) it in acidic medium reduce halogens to corresponding halides.(C) burning magnesium and potassium continue to burn in its atmosphere.(D) All above are correct.

180. In the reaction

H2SO4 + P2O5 (X) + SO3

the product (X) is :

(A) PH3 (B) H3PO4 (C) HPO3 (D) N4 P2 O7

181. The reaction between ferric salt and aqueous sodium thiosulphate produces pink colour which soon diminishes.The pink colour is due to the formation of(A) [Fe(S2O3)3]4– (B) [Fe(S2O3)2]– (C) Fe2 (S4O6)3 (D) None of these


FINAL LAP - 2019P - BLOCK ELEMENT182. Bleaching action of SO2 is due to

(A) its reducing nature (B) its oxidising nature(C) its acidic nature (D) its both oxidising as well as reducing nature

183. KClO3 + H2SO4 KHSO4 + HClO4 + (X) + H2O

In above unbalanced chemical equation, the product (X) may be(A) O2 (B) Cl2 (C) ClO2 (D) HCl

184. Which of the following statement is false ?(A) Superoxides give hydrogen peroxide and oxygen with water(B) CrO3 is an acidic oxide.(C) PbO is an amphoteric oxide.(D) Sub oxides contain more oxygen than expected from the normal valency of the element.

185. H2S is far more volatile than water because(A) Sulphur atom is more electronegative than oxygen atom.(B) Oxygen atom is more electronegative than sulphur atom.(C) H2O has bond angle of nearly 105°.(D) Hydrogen atom is loosely bonded with sulphur.

186. Which of the following has peroxy linkage ?(A) H2S2O3 (B) H2SO5 (C) H2S2O7 (D) H2S4O6

187. The term 'thio' is used in the names of all of the following compounds except :(A) Na2S2O3 (B) Na2S2O6 (C) NaSCN (D) Na2SO3

188. Which of the following product is formed by the reaction of sulphurdioxide with chlorine in presence ofsunlight ?(A) SO2Cl (B) SO2Cl2 (C) SOCl2 (D) SO3Cl

189. Consider the following compounds :(i) Sulphur dioxide (ii) Hydrogen peroxide (iii) OzoneAmong these compounds, those which can act as bleaching agents would include :(A) 1 and 3 (B) 2 and 3 (C) 1 and 2 (D) 1, 2 and 3

190. A considerable part of the harmful UV rays of the sun does not reach the surface of the earth. This is becausehigh above the earth's atmosphere , there is a layer of :(A) O3 (B) CO2 (C) SO2 (D) NO

191. Which is true statement ?(A) Sulphur trioxide exist as cyclic trimer in solid state, S3O9(B) Selenium trioxide solid is a cyclic tetramer, Se4 O12(C) TeO3 is a solid with a network structure in which TeO6 octahedra share all vertices.(D) All are correct

192. Ozone layer is being depleted. This is due to :(A) NO emission from supersonic jets (B) chloroflurocarbon used as aerosols(C) both (A) and (B) (D) none of the above

193. Estimation of ozone can be made quantitatively by :(A) decomposition into O2 and absorption of O2 into pyrogallol(B) volumetric method using KI and titration of the liberated iodine using hypo solution(C) oxidative ozonolysis method(D) all methods given above

194. The process of obtaining sulphur by the borehole method is called :(A) the Frasch process (B) the Lablanc process(C) the Calcaroni process (D) the Mannheium process


FINAL LAP - 2019P - BLOCK ELEMENT195. SO2 behaves as a reducing agent when :

(A) passed over hot CuO (B) mixed with moist H2S(C) passed through acidified KMnO4 solution (D) passed through FeSO4 solution

196. When an article is bleached by SO2 it loses its colour. The colour can be restored by :(A) exposure to air (B) heating(C) dilution (D) none of these

197. Out of H2S2O3 , H2S4O6 , H2SO5 and H2S2O8 peroxy acids are :(A) H2S2O3 , H2S4O6 (B) H2S4O6 , H2SO5(C) H2SO5 , H2S2O8 (D) H2S2O3 and H2S2O8

198. Which of the following can convert acidified Cr2O72– to green ?

(A) SO2 / H2SO3 / H2SO4 (B) SO3 / H2SO3 / H2S(C) SO3

2– / H2S / Fe2+ (D) S2O32– / SO3 / Fe3+

199. Bleaching of a fabric cloth is done using A and excess of chlorine is removed using B. A and B are :(A) CaOCl2 , Na2SO3 (B) Na2S2O3 , CaOCl2(C) CaCl2 , Na2S2O3 (D) CaOCl2 , Na2S2O3

200. Aqueous hypo solution on reaction with aqueous AgNO3 gives :(A) yellow precipitate changing to black (B) white precipitate changing to black(C) orange precipitate to blue (D) no precipitate

201. SO2 can reduce :(A) HClO3 to HCl (B) Cr2O7

2– / H+ to Cr3+ (C) MnO4– / H+ to Mn2+ (D) all of these

Group 17th

202. The most powerful oxidising agent is :(A) fluorine (B) chlorine (C) bromine (D) iodine

203. Which one of the hydracid does not form any precipitate with AgNO3 ?(A) HF (B) HCl (C) HBr (D) HI

204. The strongest reducing agent is :(A) F– (B) Cl– (C) Br– (D) –

205. Which one of the following has hydrogen bonding ?(A) HI (B) HBr (C) HF (D) HCl

206. Chlorine gas is dried over :(A) CaO (B) NaOH (C) H2SO4 (D) HBr

207. On heating a mixture of NaCl, K2Cr2O7 and conc. H2SO4 .......... is obtained :(A) chromic chloride (B) chromyl chloride (C) chlorine (D) none of the above

208. Elements of which one of the following groups will form anions most readily ?(A) oxygen group (B) nitrogen group (C) halogens (D) alkali metals

209. Which statement is correct about halogen ?(A) They are all diatomic and form univalent ions(B) They are all capable of exhibiting several oxidation states(C) They are all diatomic and form diatomic ions(D) They are all reducing agents


FINAL LAP - 2019P - BLOCK ELEMENT210. Iodine vapours are violet in colour because :

(A) the molecules of iodine in vapour phase absorb green and yellow radiations(B) the molecules of iodine absorb red and violet radiations and then emit them(C) it is a solid(D) it is easily volatile

211. The halogens are :(A) transition elements (B) inner-transition elements(C) noble elements (D) representative elements

212. Iodine is liberated from KI solution when treated with :(A) ZnSO4 (B) CuSO4 (C) NiSO4 (D) FeSO4

213. Which of the following arrangements for the three halogesn CI, Br, I when placed in order of their increasingelectron affinity is correct ?(A) Cl, Br, (B) , Br, Cl (C) Br, Cl, (D) , Cl, Br

214. Oxidising action increases in the following order :(A) Cl < Br < < F (B) Cl < < Br < F (C) < F < Cl < Br (D) < Br < Cl < F

215. Which of the following is not oxidised by MnO2 ?(A) F– (B) Cl– (C) Br– (D) I–

216. HBr and HI can reduce H2SO4, HCl can reduce KMnO4 and HF can reduce :(A) K2Cr2O7 (B) KMnO4 (C) H2SO4 (D) none

217. Which of the following pairs is not correctly matched ?(A) A halogen which is liquid at room temperature – Bromine(B) The most electronegative element–Fluorine(C) The most reactive halogen – Fluorine(D) The strongest oxidising agent – Iodine

218. Fluorine reacts with water to give :(A) hydrogen fluoride and oxygen (B) hydrogen fluoride and ozone(C) hydrogen fluoride and oxygen fluoride (D) hydrogen fluoride, oxygen and ozone

219. When iodine is dissolved in CCl4, the colour that results is :(A) brown (B) bluish green (C) violet (D) colourless

220. Hydrogen bonding does not play role in the boiling point of :(A) NH3 (B) H2O (C) HI (D) HF

221. Hydrogen fluoride is a liquid unlike other hydrogen halides, because :(A) H–F bond is strong (B) F atom is small in size(C) Hydrogen bonding is present (D) HF is a weak acid

222. Which one of the halogen acids is a liquid under ordinary conditions ?(A) HF (B) HCl (C) HBr (D) HI

223. Bleaching powder is obtained by the interaction of chlorine and :(A) dilute solution of Ca(OH)2 (B) concentrated solution of Ca(OH)2(C) dry calcium oxide (D) dry slaked lime

224. Which amongst the following reactions cannot be used for the respective preparation ?(A) 2KBr + H2SO4 (conc.) K2SO4 + 2HBr (B) NaCl + H2SO4 (conc.) NaHSO4 + HCl(C) NaHSO4 + NaCl Na2SO4 + HCl (D) CaF2 + H2SO4 CaSO4 + 2HF


FINAL LAP - 2019P - BLOCK ELEMENT225. Which of the following possess the highest bond energy ?

(A) F2 (B) Cl2 (C) Br2 (D) I2

226. Astatine is the element below iodine in the group VIIA of the periodic table. Which of the following statementsis not true for astatine ?(A) It is less electronegative than iodine(B) It will exhibit only–1 oxidation state(C) Intermolecular forces between the astatine molecules will be larger than between iodine molecules(D) It is composed of diatomic moleucles

227. When thiosulphate ion is oxidised by iodine, the new product formed is :(A) SO3

2– (B) SO42– (C) S4O6

2– (D) S2O62–

228. Which of the following is the strongest acid ?(A) HBr (B) HF (C) H2S (D) PH3

229. Which of the following statements is correct ?(A) all halogens form oxyacids (B) only chlorine and bromine form oxyacids(C) all halogens except fluorine form oxyacids (D) only iodine forms oxyacid

230. On heating KClO3 we get :(A) KClO2 + O2 (B) KCl + O2 (C) KCl + O3 (D) KCl + O2 + O3

231. The reaction3CIO– (aq.) CIO3

– (aq.) + 2Cl– (aq.)is an example of :(A) oxidation reaction (B) reduction reaction (C) disproportionation (D) decomposition reaction

232. Which of the following has highest bond strength :(A) HI (B) HCl (C) HF (D) HBr

233. Which of the following will displace the halogen from the solution of the halide ?(A) Br2 added to NaI (B) Br2 added to NaCl(C) Cl2 added to KCl (D) Cl2 added to NaF

234. The high oxidising power of fluorine is due to :(A) high electron affinity(B) high heat of dissociation and low heat of hydration(C) low heat of dissociation and high heat of hydration(D) high heat of dissociation and high heat of hydration

235. In the preparation of HBr or HI , NaX (X = Br, I) is treated with H3PO4 and not by concentrated H2SO4 since,(A) H2SO4 makes the reaction reversible(B) H2SO4 oxidises HX to X2 (Br2 , I2)(C) Na2SO4 is water soluble and Na3PO4 is water insoluble(D) Na3PO4 is water insoluble and Na2SO4 is water soluble

236. Bleaching powder is disinfectant for purification of water when water – born germs are killed. But disinfectantactivity is destroyed. It is due to its disproportionation into :(A) CaCl2 and Cl2 (B) Ca–Cl2 and Ca(ClO3)2(C) CaO and Cl2 (D) CaO, Cl2 and CaCl2

237. CaOCl2 + H2O + CO2 CaCO3 + CaCl2– + HO–Cl+

This reaction is simply :(A) oxidation (B) reduction (C) redox (D) hydrolysis in presence of CO2

238. Select correct statement :(A) Cl2O and ClO2 are used as bleaching agents and as germicides(B) I2O5 is used in the quantitative estimation of CO(C) bond angle XOX varies in the order FOF < ClOCl < BrOBr(D) all are correct


FINAL LAP - 2019P - BLOCK ELEMENT239. ClO2s is the anhydride of :

(A) HOCl (B) HClO2 (C) HClO3 (D) HClO2 and HClO3

240. ClO3 is the mixed anhydride of :(A) HClO2 and HClO3 (B) HClO3 and HClO4 (C) HClO2 and HClO4 (D) HClO2 and HClO3

.

Group 18th

241. Of the following species, one which is non-existent :(A) XeF6 (B) XeF5 (C) XeF4 (D) XeF2

242. The coloured discharge tube for advertisement mainly contains :(A) xenon (B) helium (C) neon (D) argon

243. Maximum number of compounds are known in the case of :(A) neon (B) xenon (C) krypton (D) argon

244. XeF6 on complete hydrolysis gives :(A) Xe (B) XeO2 (C) XeO3 (D) XeO4

245. Which one of the following fluorides does not exist ?(A) HeF4 (B) XeF4 (C) CF4 (D) SF6

246. In Kroll and I.C.I process of the production of titanium, the inert gas used is :(A) Ne (B) Ar (C) Kr (D) Xe

247. Which of the following gaseous molecules is monoatomic ?(A) chlorine (B) helium (C) oxygen (D) nitrogen

248. Which one of the following noble gases is not found in atmosphere ?(A) Rn (B) Kr (C) Ne (D) Ar

249. Helium is added to oxygen used by deep sea divers because :(A) It is less soluble in blood than nitrogen under high pressure(B) It is lighter than nitrogen(C) It is readily miscible with oxygen (D) It is less poisonous than nitrogen

250. The inert gas abundantly found in atomosphere is :(A) Ar (B) Kr (C) He (D) Xe

251. The hybridization of Xe in XeF2 is :(A) sp3 (B) sp2 (C) sp3d (D) sp2d (E) sp3d2

252. Select the correct matching :List I List IIA : XeF4 1. PyramidalB : XeF6 2. T-ShapeC : XeO3 3. Distorted octahedralD : XeO2F2 4. Square planar

A B C D(A) 4 3 1 2(B) 1 2 3 4(C) 2 1 3 4(D) 4 1 3 2


FINAL LAP - 2019P - BLOCK ELEMENT253. Which one of the following does not exist ?

(A) XeOF4 (B) NeF2 (C) XeF2 (D) XeF6

254. Consider following properties of the noble gases :I : They readily from compounds which are colourlessII : They generally do not form ionic compoundsIII : They have variable oxidation states in their compoundsIV : They generally do not form covalent compounds.Select correct properties.(A) I, II , III (B) II , III (C) I , III (D) I

EXERCISE - 2QUESTION FOR SHORT ANSWER :

Group 13th

1. Explain why aluminium, though an electropositive metal, finds extensive use as a structural material

2. Discuss the pattern of variation in oxidation states of the following :(i) Al to TI (ii) Si to Pb (iii) P to Bi

3. How is LiAlH4 prepared ? What is its important uses ?

4. What happens when NaOH (aq) is added drop wise to a solution of GaCl3 in water ?

5. Give formula of the following :(i) Felspar (ii) Cryolite (iii) Jeweller’s borax (iv) Corundum (v) Colemanite

6. Answer the following :(i) What is the outer electronic configuration of group IIA elements ?(ii) Name the first two elements of group IIIA.(iii) What is Tincal ?(iv) What is thermite mixture ?(v) What is inorganic benzene ?(vi) Name the two metals present in common alum.(vii) Name the aluminium compound used in Friedel Craft’s reaction.

7. What happens when :(i) Borax is heated strongly(ii) Aluminium is heated with caustic soda solution.(iii) A mixture of borax and cobalt oxide is heated in a flame.(iv) Water is added to aluminium nitride.(v) Aluminium reacts with HNO3.

8. Explain the following with relevent reason.(i) Aluminium metal is frequently used as reducing agent for the extraction of metals such as Cr, Mn, Fe, etc.(ii) AlCl3 forms a dimer but BCl3 does not form dimer.(iii) The B ____ X distance is shorter than what is expected theoretically in BX3 molecule (X = Cl, F, Br, ) ?(iv) Why boron does not form B3+ ion ?(v) Although the ionisation potential of boron (8.30 eV) is less than gold (9.22 eV), yet former is a non-metalwhile the latter is a metal.(vi) Borazine is more reactive than benzene.(vii) First ionisation potential of Al is lower than that of Mg.

9. How will you obtain.(A) Sodium peroxo borate from borax (in two steps only)(B) Borazole from sodiumboro hydride (in three steps only)

Refer text.(C) Borax from Boron (in two steps)



10. What is the importance of ultra pure elemental silicon ? How is it obtained ?

11. Write balanced equations for the following reactions :(A) SnO is treated with dil. HNO3(B) Tin is treated with an excess of chlorine gas.(C) Lead sulphide is heated in air.

12. What are silicates ? How are they classified ?

13. What are silicones ? How are they manufactured ?

14. How far do you agree with the phenomenon concept of inert pair effect ? Justify your answer.

15. Why alkali metals should not be used for drying CCl4 and other chlorocarbons?

16. Why in reactions of HCl & SO2 , PbO2 shows oxidising nature? Explain.

17. Dilute HCl is preferred over dilute H2SO4 for the preparation of CO2 from lime stone. Explain.

18. PbCl4 is less stable than SnCl4 . Explain.

19. Why does not silicon form an analogue of graphite?

20. Like CO why its analogue of SiO is not stable.

21. Why CO2 is a gas and SiO2 is solid ?

22. What happens when,(a) Mixture of R2 -SiCl2 and R3 - SiCl is subjected to hydrolysis.(b) Malonic acid is heated in presence of P4O10 .(c) Tin (IV) Chloride is exposed to moist air.

23. Explain the term "plumbosolvency".

24. CaO + C (A) + (B)

(A) + N2 (C) + carbon

(C) + H2O (D) + NH3

Identify (A), (B), (C) and (D)

25. How carbonates and bicarbonates can be differentiated from one another ?Group 15th

26. Give reasons for the following:(a) Formation of NH3 from its elements at constant pressure is accompanied by a decrease in volume.(b) Nitric oxide turns brown in air.(c) Copper dissolves in HNO3 but not in HCl.(d) Pb(NO3)2 on heating produces a pale yellow gas which on strong heating produces brown gas.

27. Write down the electron dot formula of NO, N2, N2O5, NH3, HCN, NH4+, HNO3, HNO2, PH3

28. State the property of ammonia due to which it is used in refrigeration.

29. What happens when:(a) NH4Cl & NaNO3 is heated strongly(b) NH4NO3 is heated(c) NH4NO2 is heated(d) Mg3N2 reacts with water(e) NaNO3 is heated with NaOH and Zn powder in water(f) Mg is burnt in air and the product is treated with water

30. State the conditions under which NH3 is manufactured from N2 and H2.

31. How will you obtain N2 from a mixture of N2 and CO?

32. How will you obtain :(A) Ammonia from quick lime (in three steps)

(B) H3PO4 from phosphorite (in two steps only)



(C) Meta phosphate from primary phosphate (one step)

(D) White phosphorus from red phosphorus (one step)(E) Phosphine from hypophosphorus acid (one step)

33. Commercial nitrogen is passed through copper chips kept in ammonia solution for removing oxygen. Explain.

34. Nitric acid acts only as an oxidising agent while nitrous acid can act both as an oxidising and reducingagent.

35. Write down a reaction showing action of N2O4() as non-aqeous solvent.

36. A waxy crystalline solid (A) with a garlic odour is obtained by buring white P in a stream of air. (A) reactsvigorously with hot water forming a gas (B) and an acid (C). Gas (B) has unplesant odour of rotten fish and isneutral towards litmus. When passed through CuSO4 solution gas (B) produced a black ppt. (D) What are(A) to (D) ? Give chemical equations of the reactions.

37. Why does H3PO3 act as a reducing agent but H3PO4 does not ?

Group 16th

38. Oxygen almost invariably exhibits an oxidation state of -2 but other members of the family exhibit negative aswell as positive oxidation state of +2, +4 and +6.

39. Sulphur dioxide acts as a strong reducing agent in alkaline medium.

40. Among the hydrides, H2O, H2S, H2Se which has highest bond angle.

41. Which of the following has highest boiling point and why(a) H2O (b) H2S

42. What do you understand by tailing of mercury ?

43. An inorganic halide (A) reacts with water to form two acids (B) and (C). Also aqueous solution of (A) reactswith KOH to form two salts (D) and (E) Which are soluble in water. The solution gives white precipitates withboth AgNO3 and BaCl2 solutions respectively. Identify (A) to (E) and write the chemical reactions involved.

44. From the reactions given below, identify (A), (B), (C) and (D) and write their formulae.(A) + dil. H2SO4 + K2Cr2O7 (B) Green Solution(A) + dil. H2SO4 + (C) MnSO4(A) + O2 OH2 (D)(D) + BaCl2 White ppt.

45. Arrange the following in increasing order(a) H2O, CO2, SO3, N2O5, SiO2 - Acidic character(b) H2O, H2S, H2Se, H2Te - Thermal stability

46. On heating rhombic sulpur it melts but viscosity of liquid increases upto 2000C and beyond that it decreaseswhy ?

47. O - O bond length is more in H2O2 than in O2F2 . Explain.

48. For drying H2S gas conc. H2SO4 can not be used why ?

49. Draw the structure of following acids.(a) Marshall's acid (b) Dithionic acid (c) Caro's acid (d) Thiosulphuric acid

50. Complete the following equations

(i) I2 + O3 + H2O HIO3 + ................

(ii) NaHS + .............. Na2S2O3 + H2O

(iii) (NH4)2S2O8 + H2O + MnSO4 ..............+..................+.................

(iv) Sb2S3 + HCl ...............+...............

(v) Hg2Cl2 + SO2 + HCl .................+..................+.................

(vi) CaS + H2O + CO2 ................+.................


FINAL LAP - 2019P - BLOCK ELEMENT51. What happens when

(A) FeCl3 reacts with hypo solution

(B) Mn2O7 dissolves in water.

(C) CuCl2 reacts with aqueous Na2S2O3

(D) Sulphuric acid is heated with potassium.

Group 17th

52. What happens when ? (Give balanced equations)(i) Sodium iodate is treated with sodium bisulphite solution.

(ii) Chlorine is passed through hot NaOH solution.

(iii) Chlorine is passed into aqueous potassium hydroxide.

(iv) Chlorine gas is bubbled through a solution of ferrous bromide

(v) Iodine reacts with conc. HNO3.

(vi) Chlorine is passed over slaked lime.

(vii) Potassium iodide is heated with MnO2 and conc. H2SO4.

(viii) Chlorine reacts with Na2SO3 solution.

(ix) Iodine is added to acidified stannous chloride solution

53. Explain the following with proper reason :

(i) Fluorine cannot be prepared from fluorides by chemical oxidation.

(ii) Anhydrous HCl is a bad conductor of electricity while aqueous HCl is a good conductor.

(iii) Halogens are strong oxidising agents.

(iv) The bleaching action of chlorine is permanent while that of sulphur dioxide is temporary.

(v) Iodine dissolves more in K solution than in water..

(vi) KHF2 is well known whereas KHCl2 or KHBr2 does not exist.

(vii) Ferric iodide is very unstable but ferric chloride is stable.

(viii) Fluorine does not form F3– (polyhalide) ion.

(ix) HF is not stored in glass bottles but kept in wax lined bottles.(x) HF has a greater electronegativity difference and more ionic character than HCl, HBr and HI but it is

the weakest acid.

54. Arrange the following :(i) Increasing order of thermal stability HOCl, HClO2, HClO3, HClO4.(ii) Increasing acid strength HClO, HClO2, HClO3, HClO4.(iii) Increasing oxidising power HClO, HClO2, HClO3 , HClO4.(iv) Increasing reducing nature F–, Cl–, Br–, –.(v) Increasing oxidation number of iodine 2, H, HO4. Cl.(vi) Increasing acid strength HOF, HOCl, HOBr, HO.(vii) Increasing oxidising power F2, Cl2, Br2, 2.(viii) Increasing acid strength HF, HCl, HBr, H.(ix) Increasing electronegativity or reactivity F, Cl Br, .(x) Increasing electron affinity F, Cl, Br, .

55. HI can not be prepared by heating NaI with conc. H2SO4. Give the method which is preferred for the preparationof HI.

56. Freshly distilled colourless HI (aqueous solution) gradually turns brown with time.

57. State what happens when super halogen reacts with a cold dilute solution of NaOH ?

58. Complete and balance the following reactions :(A) – CH = CH – + ICl ; (B) HCl + KIO3 + 2KI (C) SiO2 + HF ; (D) Pb3O4 + HCl ; (E) H2O2 + ClO2 + OH–



59. Answer the following with relevant reason.

(i) Why the zero group elements do not form compounds under ordinary conditions ?

(ii) Xenon has closed shell configuration but is known to give compounds with fluorine.

(iii) The boiling points of noble gases increase with increase in atomic number.

(iv) A mixture of He and O2 is used for respiration by sea divers.

(v) Why helium and neon do not form clathrate compounds with quninol ?



EXERCISE - 1SECTION (A) :Group 13th

1. B 2. C 3. C 4. A 5. B 6. B 7. C

8. D 9. B 10. C 11. C 12. A 13. B 14. D

15. C 16. D 17. A 18. A 19. B 20. B 21. C

22. D 23. D 24. D 25. A 26. D 27. D 28. C

29. B 30. B 31. D 32. C 33. D 34. D 35. C

36. A 37. C 38. C 39. B 40. D 41. C 42. B

43. C 44. C 45. C 46. A 47. B 48. A 49. B

50. C 51. B 52. C 53. B 54. D 55. A

Group 14th

56. A 57. C 58. C 59. C 60. B 61. A 62. B

63. D 64. A 65. C 66. C 67. A 68. B 69. A

70. C 71. A 72. B 73. D 74. C 75. D 76. B

77. C 78. A 79. B 80. C 81. C 82. B 83. A

84. D 85. A 86. A 87. D 88. C 89. C 90. C

91. D 92. B 93. B 94. B 95. D 96. B 97. A

98. D 99. B 100. A

Group 15th

101. D 102. D 103. A 104. B 105. B 106. A 107. A

108. A 109. C 110. C 111. A 112. D 113. D 114. C

115. B 116. C 117. A 118. B 119. D 120. C 121. D

122. D 123. B 124. C 125. C 126. B 127. C 128. A

129. D 130. A 131. C 132. D 133. B 134. C 135. D

136. C 137. B 138. C 139. A 140. D 141. C 142. D

143. B 144. A 145. C 146. B 147. D 148. D 149. B

150. D 151. A 152. D 153. D 154. B 155. C 156. C

157. C 158. A 159. A 160. D 161. B 162. B

16th Group

163. C 164. A 165. C 166. D 167. D 168. B 169. D

170. A 171. A 172. B 173. D 174. B 175. B 176. C

177. D 178. B 179. D 180. C 181. B 182. A 183. C

184. D 185. B 186. B 187. D 188. B 189. D 190. A

191. D 192. C 193. B 194. A 195. C 196. A 197. C

198. C 199. D 200. B 201. D

ANSWER KEY



202. A 203. A 204. D 205. C 206. C 207. B 208. C

209. A 210. A 211. D 212. B 213. B 214. D 215. A

216. D 217. D 218. D 219. C 220. C 221. C 222. A

223. D 224. A 225. B 226. B 227. C 228. A 229. C

230. B 231. C 232. C 233. A 234. C 235. B 236. B

237. D 238. D 239. D 240. B

Group 18th

241. B 242. C 243. B 244. C 245. A 246. B 247. B

248. A 249. A 250. A 251. C 252. A 253. B 254. B

EXERCISE - 2Group 13th

1. (a) being electropositive reacts with air or oxygen to form protective layer of Al2O3 on its surface whichprotects it form further action.(b) Cheap and light metal and forms alloys with other metal which are not easily corrode.

2. (i) Al has no d-or f-electrons. Therefore, it does not exhibit inert pair effect and consequenty, it shows anoxidation state of +3 only due to the presence of two electrons in the s-and one electron in the p-orbital of thevalence shell. As we move down the group from Ga to TI, the stability of +1 oxidation state increases whilethat of =3 oxidation decreases due to inert pair effect. For

3. 4LiH + AlCl3 etherDry Li+ [AlH4]– + 3LiCl.

Reducing agent in organic chemistry.

4. GaCl3 + 3NaOH Ga(OH)3 + 3NaClGa(OH)3 + NaOH NaGaO2 + 2H2O

5. (i) KAISi3O8 (ii) Na3AIF6 (iii) Na2B4O7.5H2O (iv) Al2O3 (v) Ca2B6O11.5H2O

6. (i) ns2 np1

(ii) Boron and aluminium(iii) It is a mineral of boron. Its composition is Na2B4O7.10H2O(iv) Mixture containing 1 part Al powder and 3 parts Fe2O3 or Cr2 O3(v) Borazole or borazine, B3N3H6 is known as inorganic benzene(vi) Common alum is the double sulphate of potassium and aluminium. Its composition is,K2SO4.Al2(SO4)3.24H2O(vii) Anhydrous aluminium chloride, AlCl3.

7. (i) Na2B4O7.10H2O OH10 2 Na2B4O7 2NaBO2 + B2O3

(ii) 2AI + 2NaOH + 2H2O 2NaAIO2 + 3H2

(iii) Na2B4O7.10H2O OH10 2 Na2B4O7 2NaBO2 + B2O3

B2O3 + CoO Co(BO2)2

(iv) AIN + 3H2O AI(OH)3 + NH3(v) Nitric acid whether dilute or concentrated hardly affects aluminium at all. Aluminium is rendered passive.A thin film of Al2O3 is formed on the surface of the metal.

8. Refer text and chemical bonding sheet.


FINAL LAP - 2019P - BLOCK ELEMENT9. (A) Refer text.

624ether

34 HB2NaBF3BF4NaBH3

362.tempt

100362 NH2.HBNH2HB

2633C200

362 HHNBNH2.HBo

(C) Borax from Boron (in two steps)

233423 NO6BOH2)SOHor(HNO6B2

227423233 COOH6OBNaCONaBOH4

Group 14th

10. Ultra pure elemental silicon is used for making semiconductors.

)g(HCl4)s(Si)g(H2)pure(SiCl 24

)g(HCl3)s(Si)g(H)s(SiHCl 23

)g(H2)s(Si)g(SiH 2Pyrolysis

K6754

11. (A) SnO + 2HNO3 Sn(NO3)2 + H2O

(B) Sn + 2Cl2 SnCl4

(C) 2PbS + 3O2 2PbO + 2SO2 ; PbS + 2O2 PbSO4

14. Inert pair effect is due to the ineffectively shielding of the s-electrons of the valence shell by the d-andf-electrons of the inner shells.

15. They violently react with alkali metals according to following reactions.

)s(C)s(NaCl4)s(Na4)(CCl4

16.22

II

2

IVClbClPHCl4bOP ;

4

II

22

IVbSOPSObOP

17. CaSO4 formed with H2SO4 forms a protective layer over lime stone and then reaction slowly ceases and stop.But CaCl2 is soluble.

18. PbCl4 is less stable than SnCl4 due to more effective inert pair effect in lead. Pb–Cl bond length is more thenthat of Sn–Cl.

19. Due to bigger atomic size of silicon, its reluctance for pp – pp bond does not allow to form graphite likestructure.

20. Low electronegativity and bigger size, Si does not have tendency to form p-p bonds like carbon.

22. (b)

COOH

104OP

2CH

COOH

C3O2 (Carbon suboxide) + 2H2O

23. Lead dissolves in water containing dissolved air due to the formation of lead hydroxide (a poisonous substance).This solvent action of water is called plumbo solvency. It increases if water contains nitrates, ammoniumsalts and organic acids, and decreases if water contains phosphates, sulphates, bicarbonates and carbonates.

24. (A) CaC2 (B) CO (C) CaCN2 (D) CaCO3 .

25. Carbonates evolve CO2 with phenol but bicarbonate do not.Soluble carbonates give pink colour with phenolphthalein but soluble bicarbonates do not.



26. (b) 2NO + O2 2NO2 (Brown)(c) Copper is placed below hydrogen in electrochemical series and does not liberate H2 from acid. However,HNO3 oxidises copper due to its strong oxidant nature.3Cu + 8HNO3 (dil.) 3 Cu(NO3)2 + 4H2O + 2NO

(d) 24223 NOON)NO(Pb (Brown)

28. Due to its high heat of vaporisation.

32. (A) COCaCC3CaO 2Cº1000800

CCaCNNCaC 222

3322 NH2CaCOOH3CaCN

(B) 2Ca3 (PO4)2 + 6SiO2 6CaSiO3 + P4O10

P4O10 + 6H2O 4H3PO4

(C) OHNaPOPONaH 2342 (D) Refer text (E) 33323 POH2PHPOH3

33. 2Cu + 8NH3 + O2 + 2H2O 2[Cu(NH3)4 (OH)2 ; O2 is removed in the form of cupra-ammonium hydroxidecomplex.

35. N2O4() NO+ (acid) + NO3– (base)

ZnCl2 + 2N2O4() Zn(NO3)2 + 2NOCl.

36. (A) P4O6 ; (B) PH3 ; (C) H3PO4 ; (D) Cu3P2The given changes are :

P + 3O2 (s) (air) P4O6 (Garlic odour) ; P4O6 + 6H2O (hot) 3H3PO4 + PH3

(A) (C) (B)(B) is PH3 having rotten fish smell and neutral towards litmus

3CuSO4 + 2PH3 Cu3P2 + 3H2SO4 (Cu3P2 is black substance insoluble in water)

37. H3PO3 contains one P–H bond and hence acts as a reducing agent but H3PO4 does not contain a P–H bond.

Group 16th

38. Oxygen has no d-orbitals while other have d-orbitals. Therefore, the paired electrons can be made unpairedby exciting electrons to d-orbitals.

39. SO2 + 2OH- SO42- + 2H+ + 2 e : reaction proceeds in forward direction as OH- concentration increases

SO2 + 2H2O SO42- + 4H+ + 2 e : as H+ concentration increases the reaction proceeds in backward

direction.

40. H2O = 104.50 ; H2S = 92.50 ; H2Se = 910

41. H2O ; intermolecular hydrogen bonding.

42. Mercury is a mobile liquid but in presence of ozone it loses its mobility due to the formation of mercurysuboxide and starts sticking to the glass. This is called as tailing of mercury. 2Hg + O3 Hg2O + O2 .

43. (A) SO2Cl2 ; (B) H2SO4 ; (C) HCl ; (D) K2SO4 ; (E) KCl

44. (A) Na2SO3 ; (B) Cr2(SO4)3 ; (C) KMnO4 ; (D) Na2SO4

45. (a) H2O < SiO2 < CO2 < N2O5 < SO3 (b) H2Te < H2Se < H2S < H2O

46. On heating, S8 rings are broken and long chain polymers are formed up to 2000C. Thus due to polymerisation,liquid becomes viscous but beyond 2000C long chains are broken into short chains and ultimately S2 moleculesare formed in the vapour phase, so viscosity of liquid decreases.



47. repulsions B.L 1.480A

48. H2SO4 acts as strong oxidising agent and, therefore, following reaction takes place.H2S + H2SO4 SO2 + S + 2H2O

49. (a) (b)

(c) (d) H O SO

SO H

55. (i) I2 + 5O3 + H2O 2HIO3 + 5O2

(ii) 2NaHS +4NaHSO3 3Na2S2O3 + 3H2O

(iii) (NH4)2S2O8 + 2H2O + MnSO4 (NH4)2SO4 + MnO2 + 2H2SO4

(iv) Sb2S3 + 6HCl 2SbCl3 + 3H2S

(v) 2Hg2Cl2 + SO2 + 4HCl 4HgCl2 + 2H2O + S

(vi) CaS + H2O + CO2 CaCO3 + H2S

Group 17th

52. (i) 2NaO3 + 5NaHSO3 3 NaHSO4 + 2Na2SO4 + H2O + 2

(ii) 3Cl2 + 6 NaOH(conc) Hot 5 NaCl + NaClO3 + 3H2O

(iii) Cl2 + 2KOH (aq) KCl + KClO + H2O

(iv) 2FeBr2 + 3Cl2 2FeCl3 + 2Br2(v) 2 + 10HNO3 2HO3 + 10NO2 + 4H2O

(vi) Ca(OH)2 + Cl2 Ca(OCl)Cl + H2O

(vii) 2K + MnO2 + 3H2SO4 2KHSO4 + MnSO4 + 2H2O + 2(viii) Cl2 + Na2SO3 + H2O 2HCl + Na2 SO4

(ix) SnCl2 + 2HCl + 2 acidified SnCl4 + 2H

53. (i) The standard reduction potential of fluorine is maximum.

+ e–

Thus, it cannot be oxidised by any other reagent. F– ion is very stable due to small size and highelectronegativity of fluorine atom.

(ii) In anhydrous state, HCl is a covalent molecule. In aqueous solution, HCl combines with watermolecule to form H3O+ and Cl– ions.

HCl + H2O H3O+ + Cl–

(iii) Halogens act as strong oxidising agents because they have high tendency to accept electron, i.e.,they have high electron affinity values. Their reduction potentials are high (positive) and decrease from F to .Thus, oxidising nature decreases from F to .

(iv) Chlorine bleaching action is due to oxidation while that of sulphur dioxide is due to reduction. Hence,the substance bleached by SO2 is reoxidised by the oxygen of the air to its original state.

(v) 2 is a covalent molecule. thus, its solubility is less in polar solvent, i.e., water. Potassium iodidecombines with iodine and forms a polyhalide which is an ionic compound. Being ionic, K3 is moresoluble.

K + 2 K3 (K+ 3–)


FINAL LAP - 2019P - BLOCK ELEMENT(vi) Hydrofluoric acid exists as dimeric molecule (H2 F2) due to hydrogen bonding. It, thus, exhibits

dibasic nature and forms two series of salts, KHF2 as [K+ and F– --- H –– F] and KF[K+ and F–]. HCland HBr exists as monomeric molecules as hydrogen bonding is not present.

(vii) – ions is a strong reducing agent. Iodide thus reduces ferric into ferrous, Cl– ion is a weak reducingagent and does not reduce Fe3+ to Fe2+ .

(viii) No d-orbitals are present in fluorine while d-orbitals are present in other halogens. The formation ofX3

– ions involves sp3 d-hybrizaion.

(ix) HF attacks glass bottles. The sodium and potassium silicates are converted into flurosilicatesNa2 SiO3 + 6HF Na2 SiF6 + 3H2O

(x) The weakest acidic nature of HF is due to following three factors :(i) Strong H–F bond as the dissociation energy is high.(ii) Large heat of dehydration dues to hydrogen bonding.(iii) Low value of electron affinity.

54. (i) HClO < HClO2 < HClO3 < HClO4 (ii) HClO < HClO2 < HClO3 < HClO4(iii) HClO4 < HClO3 < HClO2 < HClO (iv) F– < Cl– < Br – < –(v) HI < 2 < Cl < HO4 (vi) HOI < HOBr < HOCl < HOF(vii) 2 < Br2 < Cl2 < F2 (viii) HF < HCl < HBr < H(ix) < Br < Cl < F (x) < Br < F < Cl

55. HI is a strong reducing agent and, therefore, reduces H2SO4 to SO2 and itself get oxidised to 2.3Na + H3PO4 K3PO4 + H

56. 4H + O2 (air) dingtanson 2H2O + 2liberation of 2 turns H solution brown.

57. 2F2 + 2NaOH OF2 + 2NaF + H2O

Group 18th

59. (i) Zero group elements have complete electronic configuration of their outer shells, i.e. ns2 np6 (excepthelium which has 1s2), hence they do not have any tendency either to lose or accept electron/electrons or share electrons with other atoms.

(ii) Xe has relatively lower ionisation energy among inert gases and thus the outermost shell electronsof Xe are excited to d-subshell and thereby showing unpaired electronic structure. Therefore Xeshows covalent bonding with fluorine showing sharing of electron pair.

(iii) Van der Waal’s forces of attraction among molecules increase with the increase of atomic masses.Thus, higher energy is required to separate these molecules as to get gaseous state. Hence, theboiling points increase with increase of atomic masses.

(iv) Unlike nitrogen, helium is not soluble in blood even under high pressure.(v) The size of cavities formed during crystallisation of quinol is more than the size of helium and neon

atoms.


FINAL LAP - 2019SALT ANALYSIS

SALT ANALYSIS


EXERCISE - 1SECTION (A) : ONLY ONE ANSWER IS CORRECT :(a) ANIONS

(I) Dilute H2SO4 group :1. The carbonate of which of the following cation is insoluble in water ?

(A) Na+ (B) K+ (C) NH4+ (D) Ca2+

2. SO2 and CO2 both turn lime water (X) milky, SO2 also turns K2Cr2O7 /H+

(Y) green while O2 is soluble inpyrogallol (Z) turning it black. These gases are to be detected in order by using these reagents. The order is:(A) (X), (Y), (Z) (B) (Y), (Z), (X) (C) (Y), (X), (Z) (D) (X), (Z), (Y)

3. Colourless salt (A) + dil. H2SO4 + Kl blue colour with starch. (A) can be(A) K2SO3 (B) Na2CO3 (C) NH4NO2 (D) NH4Cl

4. Zinc. pieces are added to acidified solution of SO32 – . Gas liberated can :

(A) turn lead acetate paper black (B) turn lime water milky(C) give both of the above tests (D) give none of the above testsHint : SO3

2– + Zn + 8H+ H2S + 3Zn2+ + 3H2O

5. Nitrite (NO2–) interferes in the ‘ring-test’ of nitrate (NO3

–). Some of the following reagents can be used for theremoval of nitrite.I : NH4Cl (Solid)II : dil. H2SO4III : NH2SO3 H (sulphamic acid)IV : Zinc /sodium hydroxide(A) I , II (B) I, II , IV (C) I , II , III (D) II , III , IV

6. Consider following reaction ; Nitrite + Acetic acid + Thiourea N2 + SCN– + 2H2O. Formation of theproduct in the above reaction can be identified by :(A) FeCl3 / dil . HCl when blood red colour appears (B) FeCl3 / dil. HCl when blue colour appears(C) K2Cr2O7 / HCl when green colour appear (D) KMnO4 / HCl when colourless solution is formed

(II) CONCENTRATED H2SO4 GROUP AND PRECIPITATION REACTIONS7. A mixture when rubbed with dilute acid smells like vinegar. It contains :

(A) sulphite (B) nitrate (C) nitrite (D) acetate

8. Which of the following reagent turns white precipitate of AgCl yellow ?(A) NaI (B) Na3AsO3 (C) Na3AsO4 (D) NaCN

9. When a mixture of solid NaCl, solid K2Cr2O7 is heated with conc. H2SO4, deep red vapours are obtained.This is due to the formation of :(A) Chromous chloride (B) Chromyl chloride (C) Chromic chloride (D) Chromic sulphate

10. AgCl dissolves in ammonia solution giving :(A) Ag+, NH4

+ and Cl– (B) Ag(NH3)+ and Cl–(C) Ag2(NH3)2+ and Cl– (D) Ag(NH3)2

+ and Cl–

11. A mixture upon adding conc. H2SO4 gives deep red fumes. It may contain the anions pair :(A) Cr2O7

2 – and Cl– (B) Br – and Cl – (C) NO3– and Cl – (D) CrO4

2 – and NO32 –


FINAL LAP - 2019SALT ANALYSIS12. White precipitate of AgCl turns to greyish or black when :

(A) reacts with Na3AsO4 (B) expossed to sunlight(C) reacts with K2CrO4 (D) reacts with conc. HCl

13. The acidic solution of a salt produced a deep blue colour with starch iodide solution. The salt may be(A) Chloride (B) Carbonate (C) Acetate (D) Bromide

14. A colourless solution of a compound gives a precipitate with AgNO3 solution but no precipitate with a solutionof Na2CO3 . The action of concentrated H2SO4 on the compouund liberates a suffocating reddish brown gas.The compound is :(A) Ba(NO3)2 (B) CaCl2 (C) NaI (D) NaBr

15. When Cl2 water in excess is added to a salt solution containing chloroform, chloroform layer turns paleyellow. Salt contains :(A) Br– (B) – (C) NO3

– (D) S2–

16. A mixture of two colourless substance was dissolved in water. When gaseous Cl2 was passed through thesolution, containing small quantity of CCl4 a violet colour developed in organic layer. Addition of BaCl2 to theoriginal solution give a white precipitate. The mixture contains :(A) NaNO3 and AlCl3 (B) NaBr and KCl (C) MgI2 and MgSO4 (D) BaSO4 and PbCl2

17. An aqueous solution of salt containing an acidic radical X– reacts with sodium hypochlorite in neutral medium.The gas evolved produces blue black colour spot on the starch paper. The anion X– is :(A) CH3COO– (B) Br– (C) I– (D) NO2

–

18. Some white colourless crystals are heated. A cracking sound is heard and brown fumes are given off and theresidue left is yellow-brown in colour. When a glowing splinter is held in the fumes, it is relighted. The fumesconsist of :(A) O2 (B) NO2 (C) Cl2 (D) NO2 and O2

19. Nitrate is confirmed by ring test. The brown colour of the ring is due to formation of :(A) Ferrous nitrite (B) Nitroso ferrous sulphate(C) Ferrous nitrate (D) FeSO4 .NO2 .

20. Nitrates of all the metals are :(A) coloured (B) unstable (C) soluble in water (D) insoluble in water

21. Precipitate of PbSO4 is soluble in :(A) ammonium acetate (B) dilute HCl (C) dilute H2SO4 (D) none

22. There are four test tubes containing dil. HCl, BaCl2, CdCl2 and KNO3 solutions. Which of the following willidentify BaCl2 ?(A) KI (B) K2CrO4 (C) AgNO3 (D) both (B) and (C)

(b) CATIONS(I) Zero Group

23. A metal X on heating in nitrogen gas gives Y.Y on treatment with H2O gives a colourless gas which whenpassed through CuSO4 solution gives a intense blue colour. Y is :(A) Mg(NO3)2 (B) Mg3N2 (C) NH3 (D) MgO

24. Nessler’s reagent is :(A) K2 Hg4 (B) K2 Hg4 + KOH (C) K2Hg 2 + KOH (D) K2 Hg4 + K

25. Ammonia/ammonium ion gives yellow precipitate with :(A) H2PtCl6 (B) HgCl2 (C) Na3[Co(NO2)6] (D) (A) and (C) both


FINAL LAP - 2019SALT ANALYSIS(II) Ist Group

26. The Ks.p., for HgS, Ag2S and PbS are 10–31,10–45 and 10–50 respectively. The solubilities are in the order :(A) HgS > Ag2S > PbS (B) HgS < PbS < Ag2S(C) PbS > Ag2S > HgS (D) Ag2S > HgS > PbS

27. Cu2+ and Ag+ are both present in the same solution . To precipitate one of the ions and leaves the other insolution, add(A) H2S (aq) (B) HCl (aq) (C) HNO3(aq) (D) NH4NO3(aq)

28. Consider the following observation :

Mn+ + HCl white precipitate water soluble. The metal ion Mn+ will be :(A) Hg2+ (B) Ag+ (C) Pb2+ (D) Sn2+

(III) IInd Group

29. H2S in the presence of HCl precipitates group but not V group because(A) HCl activates H2S (B) HCl increases concentration of Cl–(C) HCl decreases concentration of S2– (D) HCl lowers the solubility of H2S in solution

30. Yellow ammonium sulphide solution is a suitable reagent for the separation of :(A) HgS and PbS (B) PbS and Bi2 S3 (C) Bi2 S3 and CuS (D) CdS and As2 S3

31. Black precipitate of copper dissolves in :(A) KCN solution (B) sodium sulphide solution(C) sodium hydroxide (D) boiling dilute (M) sulphuric acid

32. In which of the pair the precipitates are red and black coloured respectively and both soluble in excess KIsolution ?(A) HgI2 , Hg2I2 (B) HgI2 , BiI3 (C) Cu2I2 , AgI (D) CdI2 , PbI2

33. Which one is soluble in dilute HCl(A) AgNO3 (B) Pb(NO3)2 (C) Hg2(NO3)2 (D) Cu(NO3)2

34. A metal chloride solution on mixing with K2CrO4 solution gives a yellow ppt., soluble in aqueous sodiumhydoroxide. The metal may be(A) Mercury (B) Zinc (C) Silver (D) Lead

35. Which of the following is insoluble in dil. HNO3 but dissolves in aquaregia?(A) HgS (B) PbS (C) Bi2 S3 (D) CuS.

36. When small amount of SnCl2 is added to a solution of Hg2+ ions, a silky while precipitate is obtained. Thesilky white precipitate is due to the formation of :(A) Hg2Cl2 (B) SnCl4 (C) Sn (D) Hg

37. When excess of dilute NH4OH is added to an aqueous solution of copper sulphate an intense blue colour isobtained. This is due to the formation of :(A) CuSO4 (B) Cu(OH)2 (C) [Cu(NH3)4]2+ (D) (NH4)2SO4

38. When bismuth chloride is poured into a large volume of water the white precipitate produced is of :(A) BiO.OH (B) Bi2 O3 (C) BiOCl (D) Bi (OH)3


FINAL LAP - 2019SALT ANALYSIS(IV) IIIrd Group

39. When NH4Cl is added to a solution of NH4OH :(A) The dissociation of NH4OH increases (B) The concentration of OH– increases(C) The concentrations of both OH– an NH4

+ increase (D) The concentration of OH– ion decreases.

40. The solution of sodium meta aluminate on diluting with water and then boiling with ammonium chloride gives:(A) [Al(H2O)5OH]2+ (B) AlCl3 (C) Al (OH)3 (D) NaAl(OH)4

41. Intense blue precipitate of Fe4[Fe(CN)6]3 and sodium hydroxide solution when mixed gives :(A) soluble prussian blue (B) reddish–brown precipitate(C) deep–red colouration (D) turnbull's blue

42. Turnbull’s blue is a compound(A) Ferricyanide (B) Ferrous ferricyanide(C) Ferrous cyanide (D) Ferriferrocyanide

43. Fe2+ does not give Prussian blue colour with K4[Fe(CN)6] but on its reaction with (X), Prussian blue colourappears (X) can be :(A) MnO4

–/ H+ (B) H2SO4 (C) NH3 (D) All true

44. Fe(OH)3 and Cr(OH)3 precipitates are completely separated by :(A) Aq. NH3 (B) HCl (C) NaOH/H2O2 (D) H2SO4

45. Ferric alum gives red colour with NH4SCN due to the formation of :(A) Al(SCN)3 (B) [Fe(SCN)3]

– (C) Fe(SCN)3 (D) [Fe(SCN)]2+

46. NH4SCN can be used to test one or more out of Fe3+ , Co2+ ,Cu2+

(A) Fe3+ only (B) Co2+ , Cu2+ only (C) Fe3+ Cu2+ only (D) All

47. K4[Fe(CN)6] can be used to detect one or more out of Fe2+ , Fe3+, Zn2+, Cu2+, Cd2+ , Ca2+ :(A) Fe2+ , Fe3+ only (B) Fe3+ , Zn2+ , Cu2+ only(C) All but Ca2+ (D) All

(V) IVth Group48. To increase significantly the concentration of free Zn2+ ion in a solution of the complex ion [Zn(NH3)4]

2+

Zn2+ (aq) + 4NH 3 (aq) [Zn(NH3)4]2+ (aq)

add to the solution some :(A) H2O (B) HCl (aq) (C) NH3(aq) (D) NH4Cl (aq)

49. CoS (black) obtained in group IV of salt analysis is dissolved in aqua regia and is treated with an excess ofNaHCO3 and then Br2 water. An apple green coloured stable complex is formed. It is :(A) Sodium cobaltocarbonate (B) Sodium cobaltibromide(C) Sodium cobalticarbonate (D) Sodium cobaltobromide

50. A metal salt solution when treated with dimethyl glyoxime and NH4OH gives a rose red complex. The metal(A) Ni (B) Zn (C) Co (D) Mn.

51. An aqueous solution of colourless metal sulphate M, gives a white ppt. with NH4OH. This was soluble inexcess of NH4OH. On passing H2S through this solution a white ppt. is formed. The metal M in the salt is(A) Ca (B) Ba (C) Al (D) Zn

52. Which of the following cation does not give red colour precipitate with dimethylglyoxime (DMG) in alkalinesolution ?(A) Zn+2 (B) Ni+2 (C) Fe2+ (D) both (A) and (C)


FINAL LAP - 2019SALT ANALYSIS53. In borax bead test which compound is formed ?

(A) Orthoborate (B) Metaborate (C) Double oxide (D) Tetraborate

54. A suspension containing insoluble substance ZnS, MnS, HgS, Ag2S and FeS, is treated with 2N HCl. Onfiltering, the filtrate contains appreciable amounts of which one of the following?(A) zinc and mercury (B) silver and iron(C) manganese and mercury (D) zinc, manganese and iron

(VI) Vth Group55. Aqueous Solution of BaBr2 gives yellow precipitate with :

(A) K2CrO4 (B) AgNO3 (C) (CH3COO)2Pb (D) (A) and (B) both

56. The addition of K2CO3 (aq) to the following solution is expected to produce a precipitate in every case but thatone which does not produce precipitate is :(A) BaCl2(aq) (B) CaBr2(aq) (C) Na2SO4(aq) (D) Pb(NO3)2 (aq)

57. If crimson flame is given when an inorganic mixture is tested by flame test, it may be due to the presence of(A) Chromium (B) Strontium (C) Barium (D) Calcium

(VII) VIth Group

58. Mg is not precipitated in V group because(A) MgCO3 is soluble in water (B) Ksp of MgCO3 is high(C) MgCO3 is soluble in NH4OH (D) None.

59. The presence of magnesium is confirmed in the qualitative analysis by :(A) titan yellow solution (B) disodium hydrogen phosphate(C) magneson(I) reagent (D) all of these

SECTION (B) : ONE OR MORE THAN ONE CORRECT ANSWER :60. Cu2+ ions give white precipitate with :

(A) excess KI solution (B) potassium thiocyanate solution(C) excess KCN solution (D) potassium hydroxide solution

61. Which of the following statement (s) is/are true ?(A) Ag+ ions do not give white precipitate with concentrated HCl(B) Cu2+ ions produce a white precipitate when KCN solution is added in a small quantity(C) Hg2+ ions give deep blue precipitate with cobalt acetate and ammonium thiocyanate(D) Black precipitate of BiI3 turns orange when heated with water

62. Na2SO4 and Na2S can be distinguished from each other by using :(A) conc.H2SO4 (B) acidified KMnO4 solution(C) sodium nitroprusside solution (D) cadmium acetate solution

63. K solution is the reagent for :(A) Hg2+ (B) Pb2+ (C) Ag+ (D) Cu2+

64. Black sulphides are formed by :(A) Cu2+ (B) Sb3+ (C) Pb2+ (D) Bi3+

65. In B group of basic radicals, the yellow precipitate (s) is/are given by :(A) As3+ (B) Sb3+ (C) Sn4+ (D) Sn2+

66. Borax bead test is given by :(A) Co2+ (B) Zn2+ (C) Cu2+ (D) Ni2+


FINAL LAP - 2019SALT ANALYSIS67. Reddish brown gas is obtained when the following are treated with conc. H2SO4 :

(A) Br– (B) NO3– (C) SO3

2– (D) –

68. NH4OH dissolves which of the following completely or partially :(A) AgCl (B) AgBr (C) PbSO4 (D) Ag

69. Which of the following statement(s) is /are false ?(A) Fe3+ gives red precipitate with dimethyl glyoxime in alkaline solution.(B) Cu2+ ion with excess KI gives a dirty white ppt. which turns white on adding hypo solution.(C) A filter paper soaked in mercurous nitrate turns black in contact with ammonia gas.(D) Ag2+ gives white precipitate with BaBr2

70. Which of the following compound(s) is /are insoluble in excess aqueous sodium hydroxide.(A) ZnCl2 (B) CdCl2 (C) AlCl3 (D) MnCl2

71. Ammonium molybdate test is used for the estimation of :(A) PO4

3– (B) Mg2+ (C) As3+ (D) CH3COO–

72. The correct statement(s) is /are.(A) titan yellow solution gives red colouration with a neutral solution containing Mg+2 ions(B) solution of nitrite is decomposed by sulphamic acid.(C) Fe2+ ions give brown colour precipitate with [Fe(CN)6]3– ions solution.(D) Green precipitate of Cr(OH)3 is soluble in Na2O2.

73. Which of the following is/are correct for potassium ferrocyanide ?(A) It gives a brown precipitate with Cu2+ ions.(B) It gives a white precipitate of mixed salt with Ca2+ ions.(C) It in excess gives a bluish white precipitate with Zn2+

(D) It develops a deep red colouration with Fe3+

74. CoCl2 + KNO2 + CH3COOH [X] + H2O + KCl + CH3COOK + NO(Unbalenced equation)(A) X is a yellow crystalline solid insoluble in water(B) X is a green coloured compounds knwon as kinman's green.(C) IUPAC name of X is potassium hexanitrito –N– cobaltate (II)(D) The compound X is an inner orbital complex.


(a) QUESTIONS FOR SHORT ANSWER :

1. A compound containing acetate radical is made to react with neutral ferric chloride. The solution is thendiluted with water and boiled for 1-2 minutes. A reddish brown ppt is obtained. Give the chemical compositionof reddish brown ppt.

2. Salt + H2SO4 Coloured vapours which turns starch iodide paper blue. Identify the acid radical and thecoloured vapours giving the relevent chemical equations.

3. Which chloride of Group turns black on treatment with NH3 ?

4. Which basic radical is tested with the help of alkaline sodium stannite?

5. Which basic radicals form oxocations in aqueous solution ?

6. Which basic radical(s)/decolourize acidic KMnO4 ?


FINAL LAP - 2019SALT ANALYSIS7. Which ions cannot coexist in solution ?

8. Which radical of group IVth gives bluish white ppt with K4[Fe(CN)6] (excess).

9. What products are formed.(i) When Ag2CO3 is strongly heated.(ii) Disodium hydrogen phosphate is added to magnesium sulphate solution containing ammonium hydroxide.(iii) A solution containing Zn2+ ions is poured in an aqueous ammonia.(iv) Bi(NO3)3 solution is mixed with K and then resulting mixture is saturated with exess of K solution.(v) Disodium hydrogen phosphate is boiled with conc. HNO3 and ammonium molybdate solution.

10. Complete and balance the following chemical reactions.

(i) Cu(BO2)2 + C fused (ii) AgBr + NH4OH

(iii) Cr(OH)3 + Na2CO3 + KNO3 fused (iv) Cu(NO3)2

(v) CaSO3 + SO2 + H2O

11. Complete and balance the following reaction.(i) Na2S2O3 + FeCl3 ............... + NaCl

(ii) Na2S + CdCO3 ............... + ..............

(iii) CoCl2 + NH4CNS ............... + ...........

(b) SUBJECTIVE QUESTIONS :

1. A black colured compound (A) on reaction with dil. H2SO4 gives a gas (B) which on passing in a solution ofan acid (C) gives a white turbidity (D). Gas (B) when passed in an acidified solution of a compound (E) givesa precipitate (F) soluble in dilute HNO3. After boiling this solution when an excess of NH4OH is added, a bluecoloured compound (G) is formed. To this solution on addition of acetic acid and aqueous K4[Fe(CN)6] acholcolate precipitate (H) is obtained. On addition of an aqueous solution of BaCl2 to an aqueous solution of(E) a white precipitate insoluble in dilute HCl is obtained. Identify the compounds from (A) to (H).

2. A compound (A) is greenish crystalline salt, which gave the following reactions.(i) Additon of BaCl2 solution to the solution of (A) results in the formation of white precipitate (B) which isinsoluble in dilute HCl.(ii) On heating (A), water vapours and two oxides of sulphur (C) and (D) are liberated leaving a red brownresidue(E).(iii) (E) dissolves in warm conc. HCl to give a yellow solution (F)(iv) Solution (F) on treatment with thiocyanate ions gives blood red colouerd compound (G).Identify the substances from (A) to (G)

3. An aqueous solution of salt (A) gives a white crystalline precipitate (B) with NaCl solution. The filtrate givesa black precipitate (C) when H2S gas is passed through it. Compound (B) dissolves in hot water and thesolution gives yellow precipitate (D) on treatment with KI and cooling or orange precipitate with K2CrO4 orwhite precipitate with dilute H2SO4 solution which is insoluable in C2H5OH. The compound (A) does notevolve any gas with dilute HCl, liberates a reddish brown gas on heating. Identify the compounds (A) to (D).

4. A white substance (A) reacts with dilute H2SO4 to produce a colourless gas (B) and a colourless solution (C).The reaction between (B) and acidified K2Cr2O7 solution produces a green solution and a silghtly colouredprecipitate (D). The substance (D) burns in air to produce a gas (E) which reacts with (B) to yield (D) and acolourless liquid. Anhydrous copper sulphate is turned blue on addition of this colourless liquid. Addition ofaqueous NH3 or NaOH to (C) produces first a precipitate (white) which dissolves in the excess of the respec-tive reagent to produce a clear solution in each case. Identify (A), (B), (C), (D) and (E).

5. A mixture of two salts was treated as follows.(i) The mixture was heated with MnO2 and concentrated H2SO4 when a yellowish green gas was liberated.(ii) The mixture on heating with NaOH solution gave a gas which turned red litmus blue.(iii) Its solution in water gave red precipitate with dimethylglyoxime in alkaline solution.(iv) The mixture was boiled with KOH and the liberated gas was bubbled through an alkaline solution ofK2HgI4 to give a brown precipitate Identify the mixture of two salts.



SECTION (B) : FILL IN THE BLANKS :

(a) ANIONS

1. Carbonate gives _________ precipitate (colour of precipitate white or coloured) with silver nitrate solutionwhich is soluble in _______ .

2. Soluble bicarbonates give white precipitate with MgCl2 in ________ . (cold/hot)

3. Solution of ________ is decomposed by solid sulphamic acid.

4. Ring test is responded by ___________ as well as __________ radicals.

5. Bromine develops __________ colouration upon filter paper impregnated with fluorescein.

6. Potassium nitrite solution liberates __________ gas with acidified solution of potassium iodide.

7. Sodium bromide gives bromine gas with _________ and hydrogen bromide with _________ .

8. I– ions (not in excess) give _________ precipitate with Hg2+ ions. (red/yellow/green).

9. The formula of the deep red vapours formed on warming dichromate with KCl in concentrated H2SO4 is________.

10. SO42– ions form ______________ precipitate with Hg(NO3)2 solution (which colour precipitate).

(b) CATIONS

11. Ag+ ions gives ___________ precipitate with Na3AsO4.

12. Yellow precipitate of PbI2 dissolves in much hot water forming a __________ solution (colourless/coloured).

13. Potassium cyanide is used for separating __________ and _________ ions.

14. A solution of salt in HCl when diluted with water turns milky. It indicates the presence of ______________ .

15. Orange coloured precipitate is of ___________ (As2S3, SnS2, Sb2S3 ).

16. If the ions of group are precipitated by NH4Cl and NH4OH without prior oxidation by conc. HNO3 _________is not completely precipitated.

17. The soluble Prussian blue has chemical composition ___________ .

18. Solution of a salt in conc. HCl is blue, but turns pink on dilution. It indicates the presence of _______ radical.

19. Dimethyl glyoxime in alkaline medium is used for the identification of _________ and _________ radicals.

20. Manganese ion (Mn2+) gives _____________ coloured borax bead in oxidising flame in cold.

21. Ammonium thiocyanate is used in detection of ______________ and ______________ .

22. A salt “X” gives apple green colour in Bunsen flame and also gives brown fumes on reaction with dil. H2SO4.The salt “X” is ___________.

SECTION (C) : TRUE OR FALSE :

(a) ANIONS

1. Like CO32–, SO3

2– also gives test with baryta water, Ba(OH)2 .

2. The group reagent for the identification of sulphur containing acid radicals is sodium nitroprusside.

3. Thiourea test is given by NO2– and not by SO3

2–

4. Ag2SO3 is insoluble in dilute HNO3 .

Hint : Ag2SO3 + H+ 2 Ag+ + SO2 + H2O

5. Sodium stannite gives a black precipitate on reaction with a bismuth salt solution.

6. Nitrogen dioxide (NO2) is absorbed by ferrous sulphate solution and becomes brown.

7. Heavy metal chlorides like AgCl, HgCl2. etc. do not respond to chromyl chloride test.

8. Bright yellow precipitate of silver iodide is partially soluble in concentrated ammonia solution and fairlysoluble in hypo solution.


FINAL LAP - 2019SALT ANALYSIS9. Triodide ions (I3–) produced by the reaction of Cu2+ and KI solution are not reduced by excess of sodium

thiosulphate solution.

Hint : 2 Cu2+ + 5 I– CuI + I3– (I2 + I–)

I3– + 2 S2O32– 3 I– + S4O6

2–

10. Ammonium hydrogen sulphate on heating gives nitrogen, ammonia and sulphur dioxide gases.

11. Lead sulphate is soluble in ammonium acetate solution but barium sulphate is insoluble in dilute HCl.

(b) Cations

12. HgS dissolves in both sodium sulphide solution and aquaregia.

13. White precipitate is obtained when H2S gas is passed through a solution of copper nitrate.

14. Black precipitate of Cu(SCN)2 turns into white precipitate when it reacts with saturatd solution of SO2 inwater.

Hint : 2 Cu(SCN)2 + SO2 + 2 H2O 2 Cu(SCN)¯ (white) + 2 SCN– + SO42–

15. The group reagent for group basic radicals is NaOH.

16. In a solution containing Fe3+ and Mg2+ ions, selective precipitation of Fe(OH)3 is done by aqueousammonia in presence of NH4Cl.

17. Colour of chromium hydroxide (green) turns yellow on dissolving in NaOH solution in the presence of H2O2.

18. Sr2+ ions in very dilute solution do not give yellow precipitate with CrO42– ions.

Hint : SrCrO4 is appreciable soluble in water.

19. Ca2+ ions give yellow precipitate in presence of ammonia with potassium ferrocyanide solution.Hint : White precipitate of K(NH4)Ca[Fe(CN)6]

20. Mg2+ ions in solution gives gelatinous white precipitate of magnesium hydroxide with ammonia solutionand the precipitate is readily soluble in solutions of ammonium salts.

Hint : Mg2+ + 2 NH3 + 2 H2O Mg(OH)2 + 2 NH4+

SECTION (D) : REASONING AND ASSERTION :

DIRECTIONS :The following questions consist of two statements one labelled ASSERTION (A) and the anotherlabelled REASON (R). Select the correct answers to these questions from the codes given below :(A) Both Assertion and Reason are true and Reason is the correct explanation of Assertion.(B) Both Assertion and Reason are true but Reason is not correct explanation of Assertion(C) Assertion is true but Reason is false(D) Assertion is false but Reason is true

(a) ANIONS

1. Assertion : Baryta water becomes turbid on passing CO2 gas through it but turbidity becomes clearon passing more CO2 gas.Reason : Carbonates give white precipitate with silver nitrate solution. The precipitate becomes yellowor brown upon addition of excess of reagent.

Hint : Ag2CO3 Ag2O + CO2

2. Assertion : A solution containing S2– ions gives purple colour with sodium nitroprusside solution in alkalinemedium.Reason : Sodium nitroprusside is a complex compound and it with S2– ions undergoes ligand exchangereaction.

3. Assertion : Acidified K2Cr2O7 solution becomes green when SO2 gas is passed through it.Reason : This is an redox reaction.

4. Assertion : White crystalline precipitate of silver sulphite dissolves, if sulphite ions are added in excess.Reason : Sulphite ions decolourise the pink colour of acidified KMnO4.


FINAL LAP - 2019SALT ANALYSIS(b) CATIONS5. Assertion : Nessler’s reagent gives a brown precipitate with ammonia solution.

Reason : NH4OH gives a reddish–brown precipitate with Fe3+ ions in presence of ammonium chloride.

6. Assertion : No yellow precipitate is formed when an excess of a more concentrated (6M) solution of KIis added to a solution containing Pb2+ ions.Reason : PbI2 (yellow) does not dissolve in excess of dilute solution of KI.

Hint : PbI2 + 2 I– [PbI4]2– colourless.Reaction is reversible and shifts in backward direction on dilution with water.

7. Assertion : Cu2+ and Cd2+ ions form complexes with excess of potassium cyanide solution.Reason : On passing H2S gas stable complex [Cu(CN)4]2– is not effected.

8. Assertion : Cu+2 salts give blue bead in oxidising flame and brown red bead in reducing flame.Reason : Cu+2 salts form copper metaborate in oxidising flame and copper in reducing flame.

9. Assertion : Cd2+ salts give white ppt of Cd(OH)2 with NH4OH which gets soluble in excess NH4OH.Reason : Cd2+ salts give white ppt of Cd(OH)2 with NaOH(aq) which is not soluble in excess NaOH(aq.)

10. Assertion : A solution of BiCl3 in conc. HCl when diluted with water gives white precipitate.Reason : BiCl3 forms insoluble BiO+Cl– when diluted with a large quantity of water.

11. Assertion : NH4Cl is added while analysising the rd group basic radicals to suppress the ionisation ofNH4OH.Reason : With high concentration of OH– ions, basic radicals of other groups are also getprecipitated with group cations.

Hint : Due to common ion effect the concentrations of OH– ions is just sufficient to precipitate the cations of rdgroup as their hydroxides. (As they have low Ksp values).

12. Assertion : Borax bead test is applicable only to coloured salts.Reason : In borax bead test, coloured salts are decomposed to give coloured metal metaborates.

13. Assertion : When H2S gas is passed into an aqueous solution of ZnCl2 , Zn2+ ions are completely precipitatedas zinc sulphideReason : Zinc sulphide is insoluble in solutions of caustic alkali but dissolves in dilute HCl.

Hint : Ksp of ZnS is large and thus is completely precipitated only in presence of ammonium hydroxide.

14. Assertion : An original solution containing excess of Ni2+ ions gives a yellow coloured solution with potas-sium cyanide solution.Reason : A solution of Ni2+ ions gives red precipitate with dimethylglyoxime solution just made alkaline.

Hint : Ni2+ + 2 CN– Ni(CN)2 greenIf CN– is in excess thenNi(CN)2 ̄ + 2 CN– [Ni(CN)4]2– soluble yellow coloured complex.

15. Assertion : V group basic radicals are precipitated as their carbonates in presence of NH4OH.Reason : NH4OH maintains the pH of the solution basic.

16. Assertion : In dilute solution of strontium ions, yellow precipitate of SrCrO4 is formed with CrO42– ions.

Reason : The SrCrO4 precipitate is appreciably soluble in water, therefore, no precipitation occurs whenwater is taken in large quantity.

17. Assertion : White precipitate of Mg(OH)2 is insoluble in excess of sodium hydroxide but readily soluble insolution of ammonium salts.Reason : Mg(OH)2 is very sparingly soluble in water.

Hint : In presence of ammonium salts the reaction proceeds in backward direction forming ammonia gas.

18. Assertion : Ca2+ ions do not form any precipitate with ammonia solution.Reason : Ca2+ ions gives white precipitate of CaSO4 with dilute sulphuric acid and the precipitate is in-soluble in hot concentrated sulphuric acid.

Hint : CaSO4 + H2SO4 [Ca(SO4)2]2–.


FINAL LAP - 2019SALT ANALYSIS19. Assertion : White precipitate of zinc phoshate is soluble in ammonia.

Reason : Zinc phosphate forms a soluble complex with ammonia.Hint : Zn3(PO4)2 + 12 NH3 3 [Zn(NH3)4]2+ + 2 PO4

3– .

20. Assertion : Acidifiy the yellow solution of potassium chromate with M sulphuric acid. Add 1 mL of amylalcohol followed by 1 mL of 10% hydrogen peroxide. After gentle shaking the organic layer turns blue.Reason : The blue colouration is attributed to the formation of chromium pentaoxide.

SECTION (E) : MATCH THE FOLLOWING :

1. Column Column 1. White crystalline precipitate (a) K3 [Co(NO2)6]2. Reddish brown precipitate (b) Cr(OH)33. Yellow precipitate (c) Fe(OH)34. Green precipitate (d) PbCl2

2. Column Column 1. 2NiS + 2HNO3 + 6HCl – Evaporate to dryness (a) Black ppt & imparts greenish blue flame2. CoCl2 + 4NH4 CNS + amyl alcohol – Shake & allow to stand (b) Blue colour in organic layer3. CuCl2 + NaOH – Heat strongly (c) White ppt insoluble in conc HNO3 & HCl4. Sr(CH3COO)2 + (NH4)2 C2O4 – Mix (d) Yellow residue turns green in water

5. H2SO4 + BaCl2 – Mix (e) Yellow ppt soluble in NaOH

6. Na2CrO4 + (CH3OO)2 Pb – Mix (f) Scarlet red ppt

7. HgCl2 + KI – Mix (g) White ppt & imparts crimson red flame

3. Column (A) Column (B)(a) Fe3+ , Zn2+ & Cu2+ can be differentiated by (i) KI solution(b) PbS,CuS and CdS dissolve in (ii) Alkaline Na2SnO2 solution(c) Pb2+ gives yellow precipitate with (iii) 50% HNO3

(d) Bi3+ gives a black precipitate with (iv) K2CrO4 solution(e) [Ag(NH3)2] Cl gives back precipitate with (v) Aqueous NH3 .



ANSWER KEY

Exercise - 1SECTION (A) :(a) ANIONS(I) Dilute H2SO4 group :1. D 2. C 3. C 4. A Hint : SO3

2– + Zn + 8H+ H2S + 3Zn2+ + 3H2O

5. C 6. A

(II) CONCENTRATED H2SO4 GROUP AND PRECIPITATION REACTIONS

7. D 8. B 9. B 10. D 11. A 12. B 13. D

14. D 15. A 16. C 17. C 18. D 19. B 20. C

21. A 22. D

(b) CATIONS(I) Zero Group

23. B 24. B 25. D

(II) Ist Group

26. A 27. B 28. C

(III) IInd Group29. C 30. D 31. A Hint : 2 CuS + 8 CN– 2 [Cu(CN)4]3– + S2

2–

32. B 33. D 34. D 35. A 36. A 37. C 38. C

(IV) IIIrd Group

9. D 40. C41. B Hint : Fe4[Fe(CN)6]3 + 2 OH– 4 Fe(OH)3 ̄ + 3 [Fe(CN)6]4–

42. B 43. A 44. C 45. C 46. D 47. D

(V) IVth Group

48. B Hint : On adding HCl the equilibrium will shift in backward direction.

49. C 50. A 51. D 52. A 53. B 54. D

(VI) Vth Group

55. D 56. C 57. B

(VII) VIth Group58. B 59. D

SECTION (B) :60. AB 61. ABCD 62. ABCD 63. ABCD 64. ACD 65. AC 66. ACD

67. AB 68. AB 69. AD 70. BD 71. AC 72. BD 73. ABC74. AD


FINAL LAP - 2019SALT ANALYSISExercise - 2

SECTION (A) :(a) QUESTIONS FOR SHORT ANSWER :

1. CH3COO(OH)2 Fe (basic ferric acetate)

CH3COO¯ + FeCl3 (CH3COO)3 Fe + 3Cl¯ (Blood red coloration)

(CH3COO)3 Fe + 2H2O boiled CH3COO(OH)2 Fe (Reddish brown) + 2CH3COOH

2. 2NO2– + H2SO4 SO4

2– + 2HNO23HNO2 HNO3 + 2NO + O2

2NO + O 2NO2 (Reddish brown)

2K + 2NO2 2KNO2 + 2Starch + 2 blue.

3. Hg2Cl2 . 4. Bi3+ 5. Bi3+ gives BiO+ ion and Sb3+ gives SbO+ ion.

6. Ferrous and stannous (Fe2+ and Sn2+) 7. Fe3+ and –, Cu2+ and – , Sn2+ and Fe3+ .

8. 2 Zn(CH3COO)2 + K4[Fe)CN)6] Zn2 [Fe(CN)6] (White) + 4CH3 COOK

3 Zn2[Fe(CN)6] + K4[Fe(CN)6] 2 Zn3K2 [Fe (CN)6]2 (bluish white)

9. (i) Ag2CO3 2Ag+ CO2.

(ii) MgSO4 + NH4OH + Na2HPO4 Mg(NH4) PO4 (white) + H2O + Na2SO4

(iii) Zn2+ + 2NH4 OH Zn(OH)2 (white) + 2NH4+

Zn(OH)2 + 4NH4OH [Zn(NH3)4] (OH)2 + 4H2O

(iv) 2Bi(NO3)3 + 6K 2Bi (Black) + 6KNO3 + 322 + K K3 (Yellow solution)

(v) Na2HPO4 + 12 (NH4)2 MoO4 +23 HNO3 (NH4)3 PMo12 O40 + 2NaNO3 + 21NH4NO3 + 12H2O

(Canary yellow)10. (i) 2Cu(BO2)2 + C 2CuBO2 + B2O3 + CO

2Cu(BO2)2 + 2C 2Cu + 2B2O3 + 2CO(ii) AgBr + 2NH4OH [Ag(NH3)2] Br + 2H2O

(iii) 2Cr(OH)3 + 2Na2CO3 + 3KNO3 fused 2Na2CrO4+ 3KNO2 + 2CO2 + 3H2O(iv) 2Cu(NO3)2 2 CuO + 4NO2+ O2(v) CaSO3 + SO2 + H2O Ca(HSO3)2

11. (i) 2Na2S2O3 + FeCl3 Na[Fe(S2O3)2] (Violet or Pink coloration) + 3NaCl

(ii) Na2S + CdCO3 CdS (Yellow) + Na2CO3

(iii) CoCl2 + 4NH4 CNS (NH4)2 [Co(CNS)4] (Blue colour in etherial solution) + 2NH4Cl

(b) SUBJECTIVE QUESTIONS :1. A - FeS, CuS, PbS, HgS, CoS, NiS B - H2S

C - HNO3 D - SE - CuSO4 F - CuSG - [Cu(NH3)4](NO3)2 H - Cu2Fe(CN)6

2. A - FeSO4.7H2O B - BaSO4 C - SO2 D - SO3E - Fe2O3 F - FeCl3G - Fe(SCN)3


FINAL LAP - 2019SALT ANALYSIS3. (A) Pb(NO3)2 (B) PbCl2

(C) PbS (D) Pbl2 or PbCrO4 or PbSO4

4. (A) ZnS ; (B) H2S ; (C) ZnSO4 ; (D) S ; (E) SO2

5. The given unknown mixture contains NH4+ , Fe++ and Cl– ions or NH4Cl and FeCl2

SECTION (B) :(a) ANIONS

1. White ; Nitric acid or ammonia. 2. Hot. 3. Nitrite. 4. NO2– , NO3

– . 5. Red.

6. Iodine. 7. Concentrated H2SO4 , H3PO4 . 8. Red. 9. CrO2 Cl2

10. Yellow precipitate of basic mercury(II) sulphate, HgSO4. 2HgO .

(b) CATIONS

11. Brownish–red. 12. Colourless. 13. Cu2+ and Cd2+ ions 14. Bi3+ or Sb+3

15. Sb2S3 16. Fe2+ (ferrous ion) 17. KFe[Fe(CN)6]. 18. Cobalt (Co2+).19. Ni2+ , Fe2+ . 20. Red. 21. Co2+ and Fe3+ or Hg2+ ions. 22. Ba (NO2)2

SECTION (C) :(a) ANIONS

1. True. 2. False 3. True 4. False Hint : Ag2SO3 + H+ 2 Ag+ + SO2 + H2O

5. True. 6. True. 7. True. 8. True.

9. False. Hint : 2 Cu2+ + 5 I– CuI + I3– (I2 + I–)

I3– + 2 S2O32– 3 I– + S4O6

2–

10. True. 11. True.

(b) Cations

12. True. 13. False.

14. True. Hint : 2 Cu(SCN)2 + SO2 + 2 H2O 2 Cu(SCN)¯ (white) + 2 SCN– + SO42–

15. False. 16. True. 17. True. 18. True. Hint : SrCrO4 is appreciable soluble in water.

19. False Hint : White precipitate of K(NH4)Ca[Fe(CN)6]

20. True. Hint : Mg2+ + 2 NH3 + 2 H2O Mg(OH)2 + 2 NH4+

SECTION (D) :(a) ANIONS

1. (B). Hint : Ag2CO3 Ag2O + CO2 2. (B) 3. (B) 4. (B).

(b) CATIONS

5. (B)6. (B)

Hint : PbI2 + 2 I– [PbI4]2– colourless.Reaction is reversible and shifts in backward direction on dilution with water.

7. (B) 8. (A) 9. (B) 10. (A)

11. (B)Hint : Due to common ion effect the concentrations of OH– ions is just sufficient to precipitate the cationsof rd group as their hydroxides. (As they have low Ksp values).


FINAL LAP - 2019SALT ANALYSIS12. (A) 13. (D)

Hint : Ksp of ZnS is large and thus is completely precipitated only in presence of ammonium hydroxide.

14. (D)

Hint : Ni2+ + 2 CN– Ni(CN)2 greenIf CN– is in excess then

Ni(CN)2 ̄ + 2 CN– [Ni(CN)4]2– soluble yellow coloured complex.

15. (B) 16. (D) 17. (B)Hint : In presence of ammonium salts the reaction proceeds in backward direction forming ammonia gas.

18. (C)Hint : CaSO4 + H2SO4 [Ca(SO4)2]2–.

19. (A)Hint : Zn3(PO4)2 + 12 NH3 3 [Zn(NH3)4]2+ + 2 PO4

3– .

20. (A).

SECTION (E) :

1. (1–d), (2–c), (3–a), (4–b).

2. (1–d), (2–b), (3–a), (4–g), (5–c), (6–e), (7–f).

3. (a – v), (b – iii), (c – i, iv), (d – i,ii), (e – i,iii,iv)

(a) Fe3+ Fe(OH)3 (reddish brown) ; Cu2+ [Cu(NH3)4]2+ deep blue solution.Zn2+ [Zn(NH3)4]2+ colourless soluble complex.

(b) Dissolves in 50% HNO3 forming soluble nitrates.(c) Pb2+ + 2 KI PbI2 (yellow) + 2 K+ ; Pb2+ + K2CrO4 PbCrO4 (yellow) + 2 K+

(d) Bi3+ + 3 KI BiI3 (black) + 3 K+

BiCl3 + 3 Na2SnO2 + 6 NaOH 2 Bi (black) + 3 Na2SnO3 + 6 NaCl + 3 H2O(e) [Ag(NH3)2]Cl + KI AgI (yellow) + 2 NH3 + KCl

[Ag(NH3)2]Cl + 2 HNO3 AgCl (white) + 2 NH4NO3[Ag(NH3)2]Cl + K2CrO4 Ag2CrO4 (red) + 4 NH3 + 2 KCl


FINAL LAP - 2019METALLURGY

METALLURGY

EXERCISE - 1SECTION (A) : QUESTIONS FOR SHORT ANSWER.

1. Indicate the temperature at which carbon can be used as reducing agent for FeO.2. Name three ores which are concentrated by froth-floatation process.3. What is meant by a depressant ?

4. Which concentration method is used for separating tungsten ore particles from cassiterite ore (SnO2) ?5. Which metals are generally extracted by the electrolytic processes ?6. Which metals are obtained by self reduction of their ores ?7. Name the metals which are associated with the following terms in their extraction from their ores.

(i) Bessemer’s converter. (ii) Blast furnance

(iii) Alumino thermic process (iv) Magnetic separation8. Describe the principle of extraction of each of the following.

(i) Sn from SnO2 , (ii) Pb from PbS , (iii) Ag from Ag2S

(i) SnO2 ls Sn , (ii) PbS ls Pb , (iii) Ag2S ls Ag9. How carnallite ore is made anhydrous ?10. Cinnabar (HgS) and galena (PbS) on roasting often give their respective metals but zinc blende (ZnS) does

not explain.11. What is the role of a stabiliser in froth-floatation process ?12. Which is a better reducing agent at 983K, carbon or carbon monoxide ?13. Silver ores and gold have to be leached with sodium or potassium cyanide. Suggests a reason for this.14. Magnesium oxide is often used as the lining in steel making furnance, Explain.15. In the extraction of tin from tin stone addition of excess lime stone should be avoided.16. Why lithium is added during the refining of copper and nickel ?17. Why haematite ore is calcined in a limited supply of air and not in absence of air.18. In the extraction of lead from galena lime stone is added, why ?19. Why air is continuously passed through the suspension of the concentrated ore of silver during leaching with

the aqueous solution of sodium cyanide ?20. What is thomas slag & what is its use ?21. Why excess of carbon is added in the zinc metallurgy ?22. What is spelter ?23. Copper can be extracted by hydrometallurgy but not Zinc. Explain24. In the extractive metallurgy of iron from haematite ore, lime stone is added during smelting. Explain why.25. Alkali metals and alkaline earth metals can only be extracted by electrolytic reduction of their fused salts,

why ?26. Name the common elements present in the anode mud in elctrolytic refining of copper. Why are they so

present?27. State the role of silica in the metallurgy of copper.28. How is ‘cast iron’ different from ‘pig’ iron’’?29. Why copper matte is put in silica lined converter?30. What is the role of cryolite in the metallurgy of aluminium?31. Why is zinc not extracted from zinc oxide through reduction using CO?32. Out of C and CO, which is a better reducing agent for ZnO ?33. Predict conditions under which Al might be expected to reduce MgO.




SECTION (A) : ONLY ONE ANSWER IS CORRECT

1. Selection of temperature to carry out a reduction process depends so as to make :(A) G negative (B) G positive (C) H negative (D) H positive

2. Select correct statement(A) In the decomposition of an oxide into oxygen and gaseous metal, entropy increases.(B) Decomposition of an oxide is an endothermic change.(C) To make G° negative, temperature should be high enough so that T S° > H°.(D) All are correct statements.

3. Which of the following is not an ore ?(A) Malachite (B) Calamine (C) Salt cake (D) Cerussite

4. The reduction of an oxide by aluminium is called :(A) Ellingham process (B) Goldschmidt's aluminothermite process(C) Kroll's process (D) Van Arkel process

5. Which is not correct statement ?(A) Casseterite, chromite and haematite are concentrated by hydraulic washing (Tabling).(B) Pure Al2O3 is obtained from the bauxite ore by leaching in the Bayer's process.(C) Sulphide ore is concentrated by calcination method.(D) Roasting can convert sulphide into oxide or sulphate and part of sulphide may also act as a reducingagent.

6. Chemical leaching is useful in the concentration of :(A) copper pyrites (B) bauxite (C) galena (D) lead

7. Self-reduction of CuS to Cu can be carried out in.(A) bessemer convertor (B) blast furnace (C) both (A) and (B) (D) none of these

8. NaCN is sometimes added in the forth flotation process as a depressant when ZnS and PbS minerals areexpected because :(A) Pb(CN)2 is precipitated while no effect on ZnS.(B) ZnS forms soluble complex Na2[Zn(CN)4]while PbS forms froth(C) PbS forms soluble complex Na2[Pb(CN)4] while ZnS forms froth.(D) NaCN is never added in froth floatation process.

9. Select incorrect reduction process :(A) 2[Ag(CN)2]

– + Zn [Zn(CN)4]2– + 2Ag (B) CuO + H2 Cu + H2O

(C) ZnO + H2 Zn + H2O (D) MgO + C Mg + CO

10. Which does not represent correct method ?(A) TiCl2 + 2Mg Ti + 2MgCl2 : Kroll (B) Ni(CO)4 Ni + 4CO : Mond

(C) Ag2CO3 2Ag + CO2 + 21

O2 : Van Arkel (D) ZrI4 Zr + 2I2 : Van Arkel

11. Blister copper is :(A) Impure copper(B) Obtained in self reduction process during bessemerisation.(C) Both are correct (D) None is correct

12. Mg can be obtained(A) By heating MgCl2 (anhydrous) with Na in the atmosphere of coal gas(B) By electrolysis of fused carnallite(C) By both the methods(D) By none of the above



FINAL LAP - 2019METALLURGY13. NaCl and CaCl2 are also added to fused MgCl2 in the electrolysis of MgCl2 since :

(A) Melting point is decreased and conductivity is increased(B) Melting point is increased and conductivity is decreased(C) melting point and conductivity both are decreased(D) Melting point and conductivity both are increased

14. Black tin is(A) an alloy of Sn (B) an allotrope of Sn (C) 60-70 percent SnO2 (D) 100 percent SnO2

15. Poling process :(A) reduces SnO2 to Sn (B) oxidises impurities like iron and removes as scum(C) uses green poles (D) all of the above are correct

16. In the leaching of Ag2S with NaCN, a stream of air is also passed . It is because of :(A) reversible nature of reaction between Ag2S and NaCN(B) to oxide Na2S formed into Na2SO4 and sulphur(C) both (A) and (B) (D) None of the above

17. In electrolysis of Al2O3 by Hall-Heroult process :(A) cryolite Na3[AlF6] lowers the melting point of Al2O3and increases its electrical conductivity.(B) Al is obtained at cathode and probably CO2at anode(C) both are correct (D) none of the above is correct

18. Which mineral has been named incorrect ly ?(A) bauxite : Al2O3.2H2O (B) Croundum : Al2O3

(C) Cryolite : 3NaF .AlF3 (D) Felspar : Be3Al2Si6O18

19. Purest form of iron is :(A) cast iron (B) wrought iron (C) pig iron (D) None of these

20. Phosphorus separates, in the extraction of iron, as :(A) Slag, Ca3(PO4)2 (B) volatile, P2O5 (C) slag, Mg(PO4)2 (D) Ca3P2

21. Tempering of steel :(A) Is the heating the steel to appropriate temperature and then colling it rapidly.(B) increases mechanical strength(C) changes ratio of carbon in cementite(D) All of the above

22. Main source of lead is PbS. It is converted to Pb by :

(A) : PbS air

2C

2

COPb|SOPbO

(B) : PbS air

2SOPb|PbSPbO

Self - reduction pocess is :(A) A (B) B (C) both (D) none

23. Bessemerisation is carried out forI : Fe , II : CU, III : Al, IV : Silver :(A) I, II (B) II, III (C) I, III (D) all

24. Ag2S + NaCN + Zn AgThis method of extraction of Ag by complex formation and then its displacement is called :(A) Parke's method (B) McArthur-Forest method (C) Serpeck method (D) Hall's method

25. Identify the metal M which is present in its ore as MFeS2 :(A) copper (B) tin (C) lead (D) zinc


FINAL LAP - 2019METALLURGY26. Identify the metal M whose extraction is based on the following reactions :

MS + 2O2 MSO4 ; 2MS + 3O2 2MO + 2SO2MS + 2MO 3M + SO2 ; MS + MSO4 2M + 2SO2(A) Magnesium (B) Aluminium (C) lead (D) tin

27. Which metal is extracted using a hydrometallurgical process involving complexation?(A) Mg (B) Ag (C) Cu (D) Zn

28. The major ore of aluminium is :(A) fluorspar (B) cryolite (C) bauxite (D) carborundum

29. Which of the following metals is obtained by the Self- Reduction process?(A) Copper (B) Iron (C) Silver (D) Magnesium

30. Silver and gold are often obtained as valuable by-products during :(A) Smelting (B) Electrolytic refining (C) Zone refining (D) Iron making

31. The metal which is obtained from both sea-water and ores from the earth’s solid crust is :(A) Magnesium (B) Iron (C) Silver (D) Gold

32. The impurities present in a mineral are called :(A) gangue (B) flux (C) froth (D) nuggets

33. Sulphide ores are generally concentrated by the :(A) gravity separation process (B) calcination process(C) froth-floatation process (D) carbon-reduction process

34. Calamine is an ore of :(A) Zn (B) Mg (C) Ca (D) Pb

35. Which of the following metals cannot be extracted by the carbon reduction process?(A) Zn (B) Fe (C) Al (D) Sn

36. Which one of the following reactions represents a calcination reaction?(A) HgS + O2 Hg + SO2 (B) Ag2S + NaCl AgCl + Na2S(C) CuCO3 . Cu(OH)2 CuO + CO2 + H2O (D) Al2O3 + NaOH NaAlO2 + H2O

37. In electrorefining of metals, the anode is made of :(A) the impure metal concerned (B) the pure metal concerned(C) graphite (D) silica

38. Which of the following reactions represents the self-reduction process?

(A)

2

22

SOHgHgSHgOSOHgOOHgS

(B)

222

2222

SOCuOCuSCuSOOCuOSCu

(C)

2

22

SOPbPbSPbOSOPbOOPbS

(D) All of these

39. Which of the following represents the thermite reaction?(A) 3Mn3 O4 + 8Al 9Mn + 4Al2O3 (B) MgCO3 + SiO2 MgSiO3 + CO2(C) Cu2S + 2Cu2O 6Cu + SO2 (D) Fe2O3 + 3CO 2Fe + 3CO2


FINAL LAP - 2019METALLURGY40. During the electrolytic production of aluminium, the carbon anodes are replaced from time to time because:

(A) the carbon anodes get decayed(B) the carbon prevents atmospheric oxygen from coming in contact with aluminium(C) Oxygen liberated at the carbon anodes reacts with anodes to form CO and CO2(D) Carbon converts Al2O3 to Al

41. Electrolytic reduction of alumina to aluminium by the Hall-Heroult process is carried out :(A) in the presence of NaCl(B) in the presence of fluorite(C) in the presence of cryolite which forms a melt at lower temperature and increases the electricalconductivity(D)in the presence of cryolite which forms a melt at higher temperature and increases the electricalconductivity

42. Magnesium is extracted by :(A) the self-reduction process (B) the carbon-reduction process(C) the electrolytic process(D) treating the ore with aqueous NaCN and then reducing the mixture

43. An ore after levigation is found to have acidic impurities. Which of the following can be used as flux duringsmelting operation ?(A) H2SO4 (B) CaCO3 (C) SiO2 (D) both CaCO3 and SiO2

44. Extraction of silver from Ag2S by the use of sodium cyanide is an example of :(A) roasting (B) hydrometallurgy (C) electrometallurgy (D) smelting

45. Slag is formed by reaction between :(A) impurities and coke (B) impurities and ore (C) impurities and flux (D) flux and coke

46. Dolomite is mineral whose formula is :(A) CaMg(CO3)2 (B) MgCO3 (C) CaCO3.MgCO3 (D) (A) & (C) both

47. In the purification of aluminium by Hoope’s process, impurities of silicon and copper are added to moltenaluminium in order to :(A) make the melt conducting (B) lower the melting point of the melt(C) smooth deposit of aluminium (D) make the melt heavier

48. The slag consists of molten impurities, generally, in the form of :(A) Metal carbonate (B) Metal silicate (C) Metal oxide (D) Metal nitrate

49. Gravity separation process may be used for the concentration of :(A) Chalcopyrite (B) Bauxite (C) Haematite (D) Calamine

50. In electrorefining of metal the impure metal is made the anode and strip of pure metal the cathode during theelectrolysis of an aqueous solution of a complex metal salt. This method cannot be used for refining of :(A) Silver (B) Copper (C) Aluminium (D) Gold

51. The reason, for floating of ore particles in concentration by froth floatation process is that :(A) they are light (B) they are insoluble(C) they are charged (D) they are hydrophobic

52. The formula of carnallite is :(A) LiAl(Si2O5)2 (B) KCl.MgCl2.6H2O (C) K2OAl2O3.6SiO2 (D) KCl.MgCl2.2H2O

53. Which of the following statements is correct regarding the slag obtained during the extraction of a metal likecopper or iron ?(A) The slag is lighter and has lower melting point than the metal(B) The slag is heavier and has lower melting point than the metal(C) The slag is lighter and has higher melting point than the metal(D) The slag is heavier and has higher melting point than the metal



54. Which method of purification is represented by the equations ?

(Pure) )impure(2TiTi2Ti 2

K 16754

K 5002

(A) Cupellation (B) Polling (C) Van Arkel (D) Zone refining

55. Bauxite is leached with :(A) KCN (B) NaCN (C) NaOH (D) Na2CO3

56. Which of the following is not an ore of iron ?(A) Haematite (B) Limonite (C) Siderite (D) Malachite

57. Silver ore dissolves in dilute solution of NaCN in the presence of air to form :(A) AgCN (B) [Ag(CN)2]

– (C) AgCNO (D) [Ag(CN)3]3–

58. Which of the following metals may be present in the anode mud during electrorefining of copper?. Gold ; . Iron, . Silver ; V Magnesium(A) and (B) and V (C) and (D) and V

59. During extraction of iron flux used is :(A) Silica (B) Calcium silicate (C) Lime stone (D) Coke

60. What is the chemical composition of matte ?(A) Cu2O + FeS (B) Cu2O + Cu2S (C) FeS + SiO2 (D) Cu2S + FeS

61. Which of the following processes involves the principle of fractional crystallisation for the refining of impuremetals ?(A) Parke’s process (B) Mond’s process (C) Van Arkel process (D) Zone refining

62. Dow’s process is used for the :(A) Extraction of sodium metal (B) Purification of blister copper(C) Extraction of magnesium (D) Purification of aluminium

63. Which of the following reactions occurs during smelting in the reduction zone (in iron metallurgy) ?(A) CaO + SiO2 CaSiO3 (slag) (B) Fe2O3 + 3C 2Fe + CO

(C) Fe2O3 + CO Fe +CO (D) CO2 + C 2CO

64. The scavenger which is used in the manufacture of steel is :(A) Cr (B) Mn (C) Ti (D) Pb

65. In the metallurgy of iron, the upper layer obtained in the bottom of blast furnace mainly contains :(A) CaSiO3 (B) Spongy iron (C) Fe2O3 (D) FeSiO3

66. In the electrolysis of alumina during the manufacture of aluminium :(A) Al2O3 undergoes dissociation (B) AlF3 undergoes dissociation(C) Al2O3 and AlF3 both undergo dissociation (D) Neither of the two undergoes dissociation

67. Which one of the following statements is incorrect ?(A) Tin is extracted by carbon reduction (smelting)(B) Aluminium is extracted by Hall’s process which involves carbon reduction.(C) Extraction of lead does not involve bessemerisation(D) Silver is extracted by cyanide process



68. Poling process is used for the :(A) Reduction of CuO to Cu in impure copper(B) Purification of silver(C) Reduction of Al2O3 to Al(D) none

SECTION (B) : ONE OR MORE THAN ONE CORRECT CHOICE :

1. Which of the following statement(s) is(are) correct for the extractive metallurgy of aluminium ?(A) Red bauxite contains the impurities of iron oxides SiO2 and TiO2.(B) Red bauxite is purified by Hall’s and Serpeck’s process(C) Hall-Heroult process is used for the electrolytic reduction of molten alumina dissolved in molten cryolite.(D) In electrolytic reduction of alumina fluorine gas is liberated at anode as by product.

2. Which of the following processe(s) occur(s) during the extraction of copper from chalcopyrites ?(A) Froth floatation (B) Roasting (C) Bessemerisation (D) Leaching

3. Poiling process is used for the refining of :(A) Iron (B) Copper (C) Tin (D) Lead

4. Calcium silicate (slag) formed in the slag formation zone in extraction of iron from haematite ore :(A) does not dissolve in molten iron (B) being lighter floats on the molten iron(C) is used in cement industry (D) prevents the re-oxidation of molten iron

5. The major role of fluorspar (CaF2) which is added in small quantities in the electrolytic reduction of aluminadissolved in fused cryolite (Na3AlF6) is :(A) As a catalyst (B) To make the fused mixture very conducting(C) To lower the temperature of the melt (D) To decrease the rate of oxidation of carbon at anode

6. In the extraction of copper from chalcopyrites, the impurity of iron sulphide is removed as FeSiO3 in :(A) Electrolytic refining (B) Bessemerisation(C) Roasting (D) poling

7. Which of the following statement(s) is (are) incorrect ?(A) In Serpeck’s process silica is removed by heating the bauxite to 1800°C with coke in a current of N2

(B) In extraction of lead from galena roasting and self reduction takes place in the same furnance butunder different conditions of tempt and supply of air

(C) The tin is obtained by the carbon reduction of black tin.(D) None

8. Dolomite is a mineral of :(A) Aluminium (B) Magnesium (C) Calcium (D) Potassium

9. The anode mud obtained during electro refining of copper may contain :(A) antimony (B) Platinum (C) silver (D) gold

10. Liquation process may be applied for the purification of :(A) Copper (B) tin (C) iron (D) lead

11. In alumino-thermite process, aluminium is used as :(A) oxidising agent (B) flux (C) reducing agent (D) solder

12. Carnallite is an ore of :(A) Sodium (B) Potassium (C) Magnesium (D) aluminium

13. Which of the following statement(s) is/are correct :(A) Cuprite and Zincite are oxide ores (B) Magnesite and carnallite are carbonate ores(C) Chalcocite and azurite are ores of copper (D) Felspar and mica minerals contain aluminium.



Exercise - 1SECTION (A) :

1. Above 1270 K 2. ZnS, Cu2S, PbS

3. Substances which are used to prevent certain type of particles, from forming the froth with the bubbles bycomplexation.

4. Magnetic separation. 5. Aluminium, alkali metals and alkaline earth metals.

6. Copper, Lead, Mercury etc.

7. (i) Copper , (ii) Iron, (iii) Chrominum, Manganese (iv) Tin, Iron

8. (i) Carbon reduction of SnO2 , (ii) Self-reduction (i.e air reduction) of PbS , (iii) oxidation–reductionFor chemical reactions refer text.

9. By heating in a current of dry hydrogen chloride gas.

10. Oxide of Pb and Hg are unstable while that of zinc is stable towards heat, therefore, oxides of mercury andlead are reduced by their respective sulphides to the corresponding metals but zinc oxide does not.

11. Stabiliser like cresol and aniline tend to stabilise the froth (i.e. the froth last for longer period).

12. CO ; above 983K, CO being more stable does not act as a good reducing agent but carbon does.

13. Cyanides form soluble complex with silver and native gold from which siliver and gold can be extracted byelectrolysis or by displacement with more electropositive elements.

14. MgO acts as a basic flux and removes certain acidic impurities present in steel in the form of slag.

MgO + SiO2 MgSiO3 ; 3MgO + P2O5 Mg3(PO4)2

15. It will combine with tin to form calcium stannate.

16. It acts as a getter or scavenger as it readily combines with O2 and N2. So to remove last traces of O2 and N2

lithium is added.

17. If carbonate ore is present in haematite ore then

FeCO3 FeO + CO2

FeO reacts with SiO2 to form FeSiO3 which causes loss of iornSo ore is calcined in limited supply of air

4FeO + O2 Fe2O3

18. CaO + SiO2 CaSiO3 (slag) ; PbO + SiO2 PbSiO3

CaO converts the PbSiO3 to PbO, PbSiO3 + CaO PbO + CaSiO3 , and also prevents the formationof PbSO4.

19. In presence of air the equilibrium is shiffted in the forward direction according to the following reactions.

Ag2S +4 NaCN 2Na [Ag(CN)2] + Na2S ; 4Na2S + 5O2 + 2H2O 2Na2SO4 + 4NaOH + 2SNa2S is converted to Na2SO4 and sulphur.

20. Ca3(PO4)2, used as a valuable fertilizer

21. It reduces ZnO to Zn and also reduces CO2 to CO which is used as a fuel.

22. 97-98% pure zinc is called as spelter.

23. Zinc is highly reactive metal, so it is not possible to replace it from its salt solution like ZnSO4 , easily.

24. Remove the infusible impurities of silica as slag

CaCO3 CaO + CO2 ; CaO + SiO2 CaSiO3 (slag)

ANSWER KEY


FINAL LAP - 2019METALLURGY25. As they have low ionisation energies and are more electropositive elements, they themselves act as strong

reducing agent.

26. Selenium, tellurium, silver, gold and platinum are the metals present in anode mud. This is because theseare less reactive than copper.

27. Silica removes Fe2O3 remaining in the matte by forming silicate, FeSiO3.

28. Cast iron is made from pig iron by melting pig iron with scrap iron and coke. It has slightly lower carboncontent (>> 3%) than pig iron (>> 4% C)

29. To remove basic impurities, like iron oxide.

30. To lower the melting point and increase conductivity of the mixture.

31. The reduction may require very high temperature if CO is used as a reducing agent in this case.

32. Carbon is better reducing agent. 33. Above 1600K Al can reduce MgO.

Exercise - 2SECTION (A) :

1. A 2. D 3. C 4. B 5. C 6. B 7. A

8. B 9. C 10. C 11. C 12. C 13. A 14. C

15. D 16. C 17. C 18. D 19. B 20. A 21. D

22. B 23. A 24. B 25. A 26. C 27. B 28. C

29. A 30. B 31. A 32. A 33. C 34. A 35. C

36. C 37. A 38. D 39. A 40. C 41. C 42. C

43. B 44. B 45. C 46. D 47. D 48. B 49. C

50. C 51. D 52. B 53. A 54. C 55. C 56. D

57. B 58. C 59. C 60. D 61. D 62. C 63. C

64. B 65. A 66. B 67. B 68. A

SECTION (B) :

1. AC 2. ABC 3. BC 4. ABCD 5. BC 6. BC 7. D

8. BC 9. ABCD 10. BD 11. C 12. BC 13. ACD

objective questions based on fundamentals

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