chem16 - 2ndle reviewers.pdf

8/10/2019 Chem16 - 2ndLE Reviewers.pdf

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s t r u c t u r e i I H u m \n ffi || ||| I

T h e C N b o n d is a d o u b l e b o n d .

B. T h e r e a r e n o l o n e p a i r s o n C .

C. Ther e is a lone pair of ele ctr ons on N.

D. The C-H bond is a single bond.

6. Of the followin g, which is a state function?

A. AH

B. q

C. w

D. All of the above

7. The shorter the internuclea r distance

between two bonded atoms, the

A. Less energy need ed to break the bond

B. Less multiple bonding chara cter there is

C. More resonance

D. More energy neede d to break the bond

8. Whic h of the following is an unstab le species

and is bound not to exist?

A. H 2

B. He 2 +

C. Be 2 +

D. Be 2

9. Whic h of the following pairs have similar

molecular geometry?

A. C H 3 , CH 3 -

B. PF 5 , CIF 5

C. H 2 0, NH 2

D. None cf these10 . Which of the following ions has the largest

atomic radius?

A. Na +

B. Mg +0 o 2

D. F

1 i. Which of the followi ng atoms has the largest

first ionization energy?

A. Rb

B. Sr

C. Al

D. All have same magnitude of energy.12. What is the corr ect electronic configurat ion

for a nickel attorn?

A. 1s 2 2s 2 2p 6 4s 2 3d 2 3d 2 3d 2 3d 1 3d 1

B. 1 s 2 2s 2 2p 6 3s 2 3p 6 4 s 2 4 p 6 3 d 1 3d 1

C. 1s 2 2s 2 2p 6 3s 2 3p 6 3d 1 0

D. none of the se

2 | D L R C C h e m 1 6 L E 2 S a m p l e x

l H : ] ( C a r 1 1 ' 1 WJJJ U A

C . H - C a - H '

D . C a - H

14. Wh ich of the following is best r e p r e s e n t e d ba set of resonance structures?

A. Ammonium

B. Methane

C. Oxyg en difluoride

D. Sulfur dioxide15 . Wha t is the formal charge on N in nitr ate

ion?

A. 2

B. 2-

C. 1

D. 1-16. If there is a negative change in the Gibb' s

energy, then the reaction is said to be .

A. Reversible

B. Spontaneous

C. Exothermic

D. Endothermic17 . In the experimen t on Corrosion, the por tio n

of the nail that was oxidized was in col

and acted as the .

A. Whit e, anode

B. Pink, anode

C. Blue green , cathode

D. Blue green, anode18. In the experiment on Corrosion, zinc act ed

as the while the nail is the

A. Protec ted Anode; Sacrificial Cat hod e

B. Protect ed Cathode; Sacrificial Anod e

C. Sacrificial Cathode ; Protected Anode

D. Sacrificial Anode ; Protected Cat hode

19 Which of the following reactions is non-

spontaneous?

A. Neutralizat ion of NaOH and HCI

B. Freezing water in room temp era tur e

C. Combus tion of octane fuel

D. None of the above

2 0 . Whic h of the following statements is fal se?

A. Ferrous hydroxide is forme d by add ingsoluble Fe 3 + sample to NaOH or NH 3 .

B. Calcium will not precipitate to limiting

excess ammonia.


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f e r r i c y a n i d e .

D. The formula o f the b r o w n r i n g i n then i t ra t e t e s t i s [ F e ( N O ) ]2 + .

2 W h i c h of t he fo llowin g ion i c compoun d s ha sthe h ighes t en t ropy?A. Ca lc ium ch lo r ideB. M a g n e s i u m a r s e n a t eC . Sod ium oxa la t eD. Tin( IV) oxide

F o r n u m b e r s 2 2 - 2 6 , re fer to the s t ruc ture ofc a p s a i c i n b e l o w :

IIH3C0

H O '

22.

>3.

24.

25.

26.

27.

H 2

CH ,

H 2 H 2

H 2

Hs-C.

^CH

H

SC H '

IC H3

C H ,

T h e E G G , M G G , a n d h y b r i d i z a t i o n of is:A . Te t r a h e d r a l ; a n g u l a r ; sp 2B. Tr igona l p lan a r ; t r i gona l py ra mid a l ; sp 3C . Te t r a h e d r a l ; a n g u l a r ; sp 3

D . Tr i g o n a l p la n a r ; a n g u l a r ; sp 2T h e d i f f e r e n c e / s b e t w e e n C 2 a n d C 5 is:A. The i r EGG an d hyb r id i za t ionB. T h e i r M G G a n d h y b r i d i z a t io nC . The i r EGG an d MG GD. The i r EGG, MG G, an d hyb r id i za t ionH o w m a n y o a n d b o n d s a r e in c a p s a i c i n ?A. 43 ; 5B. 42 ; 4C. 42 ; 5

D. 43 ; 4W h a t is t he hy br id i za t ion ove r l ap in 0 4 ?A . s p 2 - s p 3B. s p 3 - s p 2C . s p 2 - s p 2D . s p 3 - s p 3T h e f o r m a l c h a rg e of N 3 is a n d t heh y b r i d i z a t i on o v e r l a p in C - N 3 - C is .A. 0; sp2-sp3-sp2B. 0; sp3-sp3-sp2C. + 1 ; sp3-sp3 '-sp2D. +1 ; sp2-sp3-sp2Whic h o f t he fo l low ing is t rue?A . M a n g a n e s e ( ll ) c a t io n s a r e d o m i n a n t in

b a s i c m e d i u m .

2 8 .

2 9 .

30.

31 .

32.

C m o r e a c i d i c m e d i u m p r o m o te scorros ion of me ta l s .

D . Z inc , N icke l , an d Coba l t c an ac t ass a c r i f i c i a l a n o d e s for Iron.

W h a t is the ne t hea t cha ng e if 2 5 . 0 ml_ of3 . 7 8 M su lfur ic a c id is neut ra l ized by 5 0 0ml_ of 1 . 9 0 M po t a s s ium hydrox ide?A. - 5 . 2 7 kJB. 5 . 2 7 kJC. 5 . 3 0 kJD. - 5 . 3 0 kJW h a t is t he D e B r og l ie w a v e l e n g th a n df r e q u e n c y of a photon wi th mass 1 . 0 8 * 1 0 2 4n a n o g r a m s ?A. 2 . 0 5 * 1 0 7 m; 1 . 4 7 x 1 01 4 s 1

B. 2 . 0 5 * 1 0 6 m; 1 . 4 7 * 1 0 1 5 s 1

C. 2 . 0 5 x 1 0 6 m; 1 . 4 7 x 1 01 4 s 1

D. 2 . 0 5X 1 0 7 m; 1 . 4 7 x 1 01 5 s 1

If the un ce r t a in ty fo r a velocity of a pho ton is

3 . 1 4 x 1 0 1 5 m/s , g iven tha t the mass of thephoton is 7 0 9 x 1 0 9 kg, what is the

u n c e r t a i n t y of the pos i t ion of the ph ot on0A. 2 . 3 7 * 1 0 - 1 2 m

B. 2 . 6 3 x 1 0 1 2 m2 . 8 6 x i 0 1 2 m2 . 4 5 x 1 0 1 2 m

CD.N i t r o g e n g a s a n d H y d r o g e n g a s r e a c t tofo rm ammonia gas . G iven tha t AHf ofa m m o n i a is - 4 6 . 3 k J , h ow m a n y g r a m s ofa m m o n i a a r e p r o d u c e d if 176 .7 kJ of h e a t isr e l e a s e d ?A. 65 .0 gB. 130.0 gC. 7 .53 gD. 3 .81 gWhich ion / s can g ive an in t e r f e r ing f a l s e r ifor n i t ra te tes t?A . T h i oc y a n a t e o n lyB. A m m o n i u m a n d t hi oc y a n a t eC . Th iocy an a te , Bromide , Iod ide

D. Su lf a t e , B romid e , Th iocya na te

3 | D L R C C. h e m 1 6 L E 2 S a m p l e x


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1. In the ozo ne laye r, O 3 < 0 a b s o r b s ha rmfu l UV rad ia t ion and fo rm s oxy gen gasSff, ,^a tom. Th e en tropy ch ang e fo r th i s p r o c e s s i s equ a l to ze ro .

2 . T h e 4f orbitals c a n a c c o m m o d a t e a m a x im u m o f 1 0 e-.3 . Hess 's L a w i s a conseq uenc e o f the fi rs t l aw of the rm odyn am ics .4 . On a hum id day, we can obse rve water vapo r to cond ense a long the outer wal l of cold dr ink bot t les

Th e format ion of the vapor is an endothermic process .5 . Th e form of ca rbon wi th a A H 0 fo rmat ion va lue o f ze ro is d iam ond .6. The azimuthal qu an tum num ber te l ls us hew far f rom the nuc leus an e lectron is .7 . The oxidat ion s ta te ass ign ed to P in the phosp hate ion is +5 .8. In the a luminum atom , the outerm ost e lectron has the qu antu m num bers n =3 , 1=1, m,=1, and m s = + 1 / 2 .9 . q S0 n is still part of q c a i eve n i f the vo lum es of the solut ion u sed for cal ibrat ion a nd calculat ion are not

constant .10. X e 0 2 F 2 ha s a t r igonal bipyram idal e lectron grou p geom etry, and a squa re pyram idal moleculat g rou p

geometry.11 . Naph tha lene , C 1 0 H 8 , i s made up of two benzene r ings "s tacked" or "glued" together. The number of

dominant resonance s t ructures of naphthalene is two.

12 . The order of hydroh al idic acids ' ionic cha racter in increasing o rde r is : < Br < CI < F.13 . Prussian blue precipi ta te f rom potass ium ferr icyanide indicates the presence of Fe 3 + ions, while from

potass ium fe r rccyan ide ind ica tes the p resence o f F e 2 + ions.

14. The net dipole moment of water explains sodium chlor ide 's miscibi l i ty in i t .

15 . In excess am mon ia , Z n 2 + w i l l fo rm a co lo r less complex [Z n( NH 3)2 ] 2 + , whi le in excess NaOH, Z n 2 + willfo rm a co lo r less complex [Zn(OH)4 ]2 " .

13. Ni t ra te ion does not exhibi t p i bond dereal izat ion.17. Adding potass ium ferr icyanide to Z n 2 + w i ll fo rm ye l low prec ip i t a te K Zn [Fe(C N)3 ], while adding

potass ium ferrocyanide wil l form white precipi ta te KZn3 [ F e ( C N )6 ] .

18. There wil l be an exothermic change in heat i f the system gives off heat to the surroundings, and thesurroundings does work to the system.

19. An exothermic react ion f rom lew entropy to high entropy wil l only proceed at h igh temperatures .2 0 . I f a react ion is endothermic f rom high entropy to low entropy, the reverse react ion is non-spontaneous.

I. C A U S E A N D E F F E C T . Determ ine the effect of the cause s ta ted in the f i rs t column on the parame ter inthe second assuming al l o ther var iables are held constant .

E f f e c t s : Increase , Decrease, No Effect

C a u s e Paramete r Effect1. Ac tual molar i ty of the acid is grea ter than the

recorded va lue .Magni tude ofcalculated AH

2 . Th e cyl inder used for me asu ring the basesolut ion was wet .

Magni tude ofcalculated AH

3. Th e s tudent pul led the therm om eter out of these t -up to t ake t empera tu re read ings .

Magni tude ofcalculated AH

4 . Th ere is a t iny hole in the Cork, exp osin g theinside of the calor imeter."* - Ma gni tude of

calculated C c a i. Ac tual molar i ty of the base is greater than therecorded va lue .

- Ma gni tude ofcalculated C c a i

4 | D L R C C h e m 1 6 L E 2 S a m p l e x


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P S : T h e r m o c h e m i s t r y1. Calculate the standard enthalpy of formation of gaseous diborane, B 2 H 6

using the following thermochemical equations,4 B (S ) + 3 0 2 ( g ) ^ 2 B 2 0 3 ( S ) AH = -2509.1kJ2 H 2 ( g ) + 0 2 ( g ) - 2H 2 0 (l ) A H0 = -571.7kJB 2 H 6 ( S ) + 3 0 2 ( g ) - B 2 0 3 s) + 3H 20 (i) AH0 = -2147kJ

2. A 0.500 g sample of solid N H4 N 0 3 was completely dissolved in waterinside a coffee cup calorimeter with an initial temperature of 24.5C.The molar mass of N H 4 N 0 3 is 80.06 g/mol.a. If the final temperature was 22.8C, what is the heat capacity of the

calorimeter? The heat of dissolution of N H 4 N 0 3 ( s ) in water is 28.1kJ/mol.

b. What would be the expected temperature range in the sam ecalorimeter if 1.80 g of N H 4 N 0 3 ( s ) was completely dissolved inwater?

3. Determine the amount of heat (in kJ) given off when 1.26 x 1 04 g ofammonia are produced according to the equationN 2 ( g ) + 3 H 2 ( g ) - 2 N H 3 ( g ) AH0 = -92.6 kJ/mol

Assume that the reaction takes place under standard stateconditions at 25 C. ^

4. The alcohol in most liquor is ethanol, C 2 H 5O H . It is produced by thefermentation of the glucose in fruits and grains.

C 6 H 1 2 0 6 aq - 2C 2 H 5 OH i + 2C0 2 g )

AH = -82.4kJ, AG = -219.8kJCalculate AS 0. Is the sign reasonable?

5. Predict the sign of AS for the following:a. weeding of the gardenb. dissolv ing instant coffee in hot waterc. addition of Zn dust to aqueous hydrochloric acidd. CC I4 ( I ) + 5 0 2 ( g ) - C 0 2 ( g ) + 4 C I 0 2 ( g )c. Precipitating copper(ll) hydroxide

6. Discuss the effect of temperature change on the spontaneity of thefollowing reactions at 1.0 atm.

a. 2PbO ;s ) + 2 S 0 2 ( g ) - 2 P bS (s ) + 3 0 2 ( g ) A H0 = +830.8 kJ/molb. 2As (s ) + 3 F 2 ( g ) - 2AsF3(i) AH0 =-1643 kJ/molc. S0 2 (g ) + CO g ) + H 2 g) - COS(g) + 2H 20 (i) endothermic

7. A 1.397-gram sample of thymol, C 1 0 H 1 4 O (s ) a preservative and a moldand mildew preventive), is burned in a bomb calorimeter assembly.a. Show the balanced chemical equation for the combustion of thymol.b. The temperature increase is 11.23 C and the heat capacity of the

bomb calorimeter is 4.68 kJ/C. W hat is the heat of combustion ofthymol, expressed in kilojoules per mole?

8. Kalburo or calcium carbide (CaC 2), is used to hasten the ripening offruits. It is prepared by reacting calcium oxide w ith graphite, producing

carbon monoxide as by-product. When one mole of calcium carbide isformed, 468.4 kJ is absorbed.a. Write the thermochem ical equation for this reaction.b. Is this reaction exothermic or endothermic?c. What is the heat of reaction when 1.20 kg of Ca C 2 is produced?d. How many grams of graphite are used up when 40.00 kJ of heat is

absorbed?

9. Isooctane is a primary component of gasoline and gives gasoline itsoctane rating. Burning 1.00 mL of isooctane (density = 0.688g/mL)releases 33.0 kJ of heat. When 1 0.0 mL of isooctane is burned in abomb calorimeter, the temperature in the bomb rises from 23.2C to66.5C.What is the heat capacity of the bomb calorimeter?

10. Use bond energies to estimate the enthalpy of reaction for each of thefollowing gas phase reaction: CH 4 + Cl 2 -* C H 3CI + HCIBond energies (kJ/m ol of bond): C-H (413), C-CI (339), CI-CI (242),H-CI (432)

1 1 . Which substance has a AHf=0?a - 03 g) b. C cj, a n l 0 n c j) C Pt S) d. Cl g)

12 . Substitute natural gas (SNG) is a gaseous mixture containing C H 4 ( g jthat can be used as fuel. One reaction for SN G is

4 CO ,,, - 8 H f 3 C H . C 0 2 9 . 2 H 2 0,/,


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Use the appropriate data from the following list to determine AH for thisSNG reaction.

13. Compute AH, AS0 and AG 0 for each of the following reactions. Statewhether they are spontaneous or not.

a ) 4 NH3 g ) + 7 0 2 q i - 4 N O ^ + 6 H2Olg}

b ) 2 H 2 0 2 f f l + N 2 H 4 ^ - N 2^ ; 4 H 2 O w

species S J .mol K) A H k J m o l )N H : , ,y , 192 3 4 6.1

2 0 5 0N O , , . , 2 4 0 . 0 - 3 3 . 2H 2 O 0 1 8 8 . 7 241 . 8H O . . 6 9 . 9 2 8 5 . 8

H 2 O 2 - 109 6 187 8N 2 H 4 , a , 121 .2 r 5 0 . 6

N 2 , ; 191 .5C H , , . , , 186 2 7 4 . 8CI:- ,7 . 2 2 3 0

201 7 1 3 4 . 5H C I . ; 186 8 92 3

56 5 . 167 2116 12 2 3 0

I , M 1.3 -55 2

14. Write a balanced equation for the formation of 1 mole of CH3O H (l ) fromits elements in their standard states a nd include AH f. AHfCH30H(i) (-238.6kJ/mol)

15. Liquid hydrogen peroxide decomposes to liquid water and oxygen gasat constant pressure.

a. Write a thermochemical equation for the reaction.b. If 7.5 grams of H 2 2 was initially present, find the value of q

accompanying its decomposition.

16. For the reaction2 CO(g) + 2 H2(g) - C0 2 (g) + CH4(g)

a. Determine the AG for the reaction at 25C. Given AH' = -247 .3kJ/mol and AS' = -256.5 kJ/mol-K.

b. Is the reaction spontaneous at 15C?

17.50.0 mL 1.00 M HCI03 and 100.0 mL of 0.50 M NaOH aqueous. solutions are placed in a calorimeter. Initially, the solutions are at

23.5'C. After the reaction, the temperature reading was 25.8'C. The

calorimeter has a heat capacity of 1.45 kJ/'C and the resulting mixtureis assumed to have the same specific heat capacity as that of water(4.184 J/gC). If the solution has a density of 1.18 g/mL, calculate theheat of the system. (Hint: The heat of the system is the sum of the heatabsorbed by the calorimeter and the heat absorbed by the solution)

18. The combustion of hydrogen chloride vapor produces chlorine gas andwater and releases 101.2 kJ of heat per mole of oxygen used in thereaction.a. Provide balanced thermoch emical equation.b. How much heat was involved in combusting 50.0 grams of

hydrogen chloride?

19. Calculate the enthalpy (in kJ) of the reaction:H2(g) + Cl2(g) - HCI (g)

given the following reactions:NH 3(g) + HCI(g) NH4CI(s) + 176.0 kJN2(g) + 3H2(g) - 2NH3(g) + 92.22 kJN2(g) + 4H2(g) + Cl2(g) ^ 2NH4CI(s) + 628.86 kJ(Hint: Balance the equation first.)


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Chem 16 DG August 29, 2013

1. ) For each of the mo lecule be low, give the fo l low ing :

S Correct Le wis structureS Electron group geom etry

S Molecu lar group geometry

S Bon d Polar i ty

S Molecu lar Polar i ty

S Expected bond angles

S Designated bond types spec ify the bond foun d in between atoms)a. ) Xe F 4b. ) C O 32 anion

2. ) Draw the proper L ew is structure of the follo wi ng salts. Indicate the form al charge for each3-a . ) N a 3 B 0 3 s Y t #V i 8 = o * c ; d i k natom appearing in your structurea . ) N a 3 B 0 3

b. ) l i th ium tr iodide L i l3 ) r_L; 3 + rv i z 1'. J

3 . ) Given the molecular s tructure o f re t inol , or Vi ta min A , b elow:


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orrmm& [Aug 15 xii e CMCA3 ; : V c l \ . 4 U

: r t V \ o c - N l I - r

\

^ 0 = - j j


9/9

\ \ ^ f l ^ i c Y v o l

^

1 ^ ^ . - .

u

C xtl jrr ^WvJJ.

chem16 - 2ndle reviewers.pdf

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