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Chemistry 12th ClassCOMPLETION AND BALANCING OF EQUATIONS

Complete and balance the following equations:

1. K2MnO4 + Cl2

2. S + HNO3

3. CuSO4 + KI

4. P + HNO3

5. HCl + HNO3

6. Al + NaOH + H2O

7. FeCl3 + H2S

8. CH2 = CH2 + H2O 4SO2H

9. Zn + NaOH

10. Al + H2SO4 (conc)

11. KMnO4 + H2O2 Medium

Neutral

12. AgNO3 + NH3

13. C2H6 + O2

14. Co + NaOH

15. Ag + HNO3

16. C + H2SO4

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17. CaH2 + H2O

18. N2 + Al eTemperatur

Elevated

19. KOH + Al + H2O

20. H2O + Cl2

21. KMnO4

Heat

22. HNO3 + Fe Dilute

Cold

23. HNO3 + Fe Conc

Hot

24. HNO3 + C

25. CH3COONa + NaOH

26. CH3MgBr + C2H5OH

27. C2H5Cl + Ag2O

28. HCHO + Ag(NH3)2OH

29. Zn + NaOH

30. CuSo4 + NH3

31. K2Cr2O7 + KCl + H2SO4

32. HC º CH + AgNO3





33. C2H6 + Cl2 h

34. H2SO4(90%) + Zn

35. HNO3 + Zn Conc

Hot

36. HNO3 + Zn Dilute

Cold

37. NaH + C2H5OH

38. Al + H2SO4

Dilute

39. ZnS + HCl

40. Cu + HNO3

Dilute

41. HNO3 + NH4OH Conc

42. PbCrO4 + NaOH

43. Co + H2 + NaOH

44. Zn + NaOH

45. Cu + HNO3

Conc

46. Cu + HNO3

Dilute

47. Zn + HNO3

Dilute





48. S + HNO3

49. Si + HNO3

50. HCl + HNO3

51. Cu + H2SO4 Conc

Hot

52. NH4Cl + NaOH

53. Cu2O + Cu2S

54. Na2CO3 + SiO2

55. PbO + O2

Heat

56. Na2B4O7 + H2O

57. AgNO3 + NaOH

58. Ca(OH)2 + Cl2

59. NaOH + H2O + Al

60. Al + Fe2O3

61. Al + HCl

62. CH º CH + H2O + [O] Cold

4KMnO

63. CH º CH + 4[O] Hot

4KMnO





64. H-HO + [Ag(NH3)2]OH Warm

65. H-CHO + Cu(OH)2 + NaOH Warm

66. CH3-HO + [Ag(NH3)2]OH Warm

67. C2H5 – Mg – Cl + H+OH-

68. C2H5OH + Na

69. C2H5OH + C2H5-COOH 4SO2H

70. HCHO + NaOH

71. CH3-CO-CH3 + I2 + Na2CO3

72. H2S + Br2

73. H3BO3 + NaOH

74. SO2 + Cl2

FILL IN THE BLANKS

Five Year Papers

1. Plastics are polymers of __________.

2. From crude oil, additional quantity of petrol is obtained by __________ process.

3. Tertiary alkyl halides react by __________ reaction mechanism.

4. __________ period is incomplete.

5. Elements, which follow actinium, are called __________ elements.

6. Ionic hydrides are also called __________.

7. Compounds with the general formula CnH2n + 2O are called __________.

8. Resorcinol is not an alcohol but a __________.





9. A ketone contianing different alkyl radicals is called __________ ketone.

10. The hydrolysis of fats and oils with a strong alkali is called __________.

11. __________ is active in the stomach of young children.

12. The chemical name of Lunar caustic is __________.

13. Aluminium resists corrosion due to the formation of __________.

14. EDTA is a __________ ligand.

15. The chemical formula of rust is __________.

16. Sub-Group B elements are called __________ elements.

17. The hybridization of carbon in graphite is __________.

18. The chemical name of vitamin B2 is __________.

19. The reactions between metallic sodium and alkyl halides are called __________ reaction.

20. The fractional distillation of crude petroleum yields only __________% petrol.

21. Starch and Cellulose are the examples of __________ carbohydrates.

22. AgCl dissolves in ammonia to form __________.

Chapter 1

Periodic Classification of Elements

1. In 1913 Moseley, A British physicist, found that a __________ is the fundamental property of an atom.

2. In the modern Periodic table recommended by the International Union of Pure and Applied Chemistry (IUPAC) in 1982, the elements are arranged in the ascending order of __________.

3. Horizontal rows of elements in the periodic table are called __________.

4. The vertical columns of elements arranged in the Periodic table are called __________.

5. In the Modern Periodic Table there are __________ periods.

6. The first period of Modern Periodic Table contains __________elements.

7. Hydrogen lies in __________ Period.

8. Helium lies in __________ Period.

9. All the elements belonging to the second period are __________.

10. Second period contains __________ elements.

11. The elements of the second period of the modern Periodic table are __________.

12. Third period of periodic table contains __________ elements.

13. The elements of the fourth period of the modern periodic table are __________.Url: http://www.pakchoicez.com | http://www.smsbundle.com | http://www.jazzbudget.com Page - 6




14. Fourth period of Modern Periodic Table contains __________ elements.

15. Fifth period of Modern Periodic Table contains __________ elements.

16. Those elements, which have ‘d’ orbitals in the process of completion in the form of ions or atoms, are called __________.

17. Elements in IB group are called __________.

18. Those elements, which involve ‘s’ orbital filling in their valence shells, are called __________.

19. The sixth period of Modern Periodic Table contains __________ elements.

20. The longest period of modern Periodic Table is __________.

21. The eight ‘s’ and ‘p’ block elements in the 4th and 5th periods are known as __________.

22. The elements of group IA and IIA are classified as __________ elements.

23. The seventh period of modern Periodic table contains __________ elements.

24. The elements on the right hand side of the Periodic table are called __________.

25. The outer most shell involved in chemical bonding are called __________.

26. The number of electrons in the outermost or valence shells is called __________.

27. Na2O is strongly __________ in nature.

28. Cl2O7 is strongly __________ in nature.

29. Greater the electronegativity of an element, stronger is the __________ character of its oxide.

30. In case of transition elements, the last electrons are received by __________.

31. Elements in group IB, IIB through VIIB are known as __________.

32. Elements in group IB, IIB through VIIB are known as __________.

33. Elements in the group VI A and __________ are the most active non-metals.

34. The correct order of second ionization potential of carbon, nitrogen, oxygen and fluorine is __________.

35. The elements having seven valence electrons are known as __________.

36. The elements of group IIIA to VIIA are called __________.

37. Maximum number of electrons present in sixth period is __________.

38. The elements of group VIIIA are called __________.

39. In case of inner transition elements the last electrons are received by __________.

40. In case of outer transition elements the last electron are received by __________.

Chapter 2

HydrogenUrl: http://www.pakchoicez.com | http://www.smsbundle.com | http://www.jazzbudget.com Page - 7




1. Hydrogen was first prepared by Cavendish in 1766 by the action of __________.

2. Hydrogen is evolved by the action of cold diluted HNO3 on __________.

3. Hydrogen is found in nature in combined state. The most abundant compound of hydrogen is __________.

4. The electronic configuration of hydrogen atom is __________.

5. Hydrogen forms slat like hydrides with the elements of __________.

6. Hydrogen forms interstitial hydrides with the elements of __________.

7. An example of covalent hydride is __________.

8. Alkali metals need __________ electron to complete their outermost shells.

9. The number of isotopes of hydrogen is __________.

10. 1H1 is symbol of __________.

11. 1H2 is the symbol of __________.

12. 1H3 is the symbol of __________.

13. The number of neutrons in the nuclei of tritium atom is __________.

14. The number of neutrons in the nucleus of protium is __________.

15. The mass number of deutrium is __________.

16. Tritium is present to the extent of one atom in __________ atoms.

17. Chemical formula of heavy water is __________.

18. Hydrogen is obtained industrially as a by-product during electrolysis of __________.

19. Hydrogen is commercially prepared by the thermal decomposition of

20. Hydrogen burns in air with __________ flame.

21. Density of hydrogen is about of 1/14th of that of __________.

22. The electronegativity of hydrogen is __________.

23. The bond energy of hydrogen is __________.

24. Hydrogen liquefies at __________.

25. Hydrogen freezes at __________.

26. The symbol of hydride ion is __________.

27. Hydrogen burns on ignition in the presence of oxygen to produce __________.

28. Hydrogen reacts on heating with P directly to form __________.

29. The hydrides formed by the combination of non-metals of groups IVA, VA, VIA and VIIA with hydrogen are called __________.





30. LiAlH4 is an example of __________.

31. The atomic weight of heavy hydrogen is __________.

32. __________ is the commonest gas in the atmosphere.

33. The element, which does not make salt like hydride is __________.

Chapter 3

S-Block Elements

1. In s-block elements the outermost orbitals are filled with __________ electrons at the outer most.

2. S-block elements consist of __________.

3. The colour of the flame of potassium is __________.

4. On bunsen flame sodium gives __________.

5. On bunsen flame Potassium gives __________.

6. On bunsen flame Cesium gives __________.

7. On bunsen flame Calsium gives __________.

8. On bunsen flame Strontium gives __________.

9. On bunsen flame Barium gives __________.

10. Alkaline earth metals are relatively __________ reactive than alkali metals.

11. An apparatus used for commercial preparation of sodium is named as __________.

12. Baking soda is also called __________.

13. The radius of K-atom is 2.31A°. The radius of K+ will be __________.

14. Bicarbonate of alkali metals and alkaline earth metals are formed by passing __________ through a solution of the carbonates of alkali metals or a suspension of carbonates of alkaline earth metals in water.

15. Metallic sodium was first obtained by Sir H. Davy in 1807 by the electrolysis of fused __________.

16. Gay Lussac and Thenard in 1811 prepared sodium by reducing sodium hydroxide with __________.

17. The process in which sodium was prepared by distilling sodium carbonate with carbon and a small amount of chalk as a catalyst was introduced by __________.

18. Down’s cell is used for the production of __________.

19. The density of sodium metal is __________.

20. Melting point of sodium is __________.

21. Boiling point of sodium is __________.

22. The annual consumption of NaCl is about __________.





23. __________ percentage of NaCl is present in sea water.

24. __________ percentage of NaCl or Common salt is present in rock salt.

25. Sodium carbonate is generally called __________.

26. Sodium carbonate is prepared by __________.

27. Aqueous solution of sodium carbonate on heating gives sodium carbonate and __________.

28. __________ is medically used for the treatment of hyperacidity in the stomach.

29. In firge extinguishers __________ is used as a source of carbon dioxide.

30. Mixture of sodium bicarbonate and crystals of vegetable acids, e.g. tartaric acid or citric acid is known as __________.

31. Anhydrous sodium carbonate is called __________.

32. Industrial use of sodium carbonate is in the manufacture of __________.

33. __________ is used in the smelting of iron ores of high sulphur content.

34. Sodium Hydroxide is manufactured on large scale by electrolysis of aqueous solution of __________.

35. Nelson’s cells is used for the manufacture of __________.

36. Castner-Kellner Process is used for the production of __________ on industrial scale.

37. The melting point of NaOH is __________.

38. NaOH decomposes into its elements at about __________.

39. Bleaching powder is manufactured by treating lime with chlorine in __________.

40. The colour of bleaching powder is __________.

41. Bleaching powder smells strongly like __________.

42. When bleaching powder is treated with strong solution of ammonia, __________ gas is evolved.

43. Calsium sulphate occurs in nature as dihydrate salt called __________.

44. Gypsum can be prepared by the action of dilute sulphuric acid on __________.

45. At __________ temperature gypsum loses its three fourth of water.

46. Gypsum is sparingly soluble in water. Its solubility increases with rising temperature up to __________.

47. Magnesium sulphate is usually sold as hydrated salt called __________.

48. Epsom salt is prepared from magnesite MgCO3 on boiling with dilute __________.

49. Epsom salt loses six molecules of water at __________.

50. Epsom salt becomes anhydous at __________.

51. Epsom salt is converted into magnesium oxide by heating it with carbon at about __________.Url: http://www.pakchoicez.com | http://www.smsbundle.com | http://www.jazzbudget.com Page - 10




52. __________ is used in medicine as purgative.

Chapter 4

P-Block Elements

1. The elements, which belong to III-A group to VIII-A group, are called __________.

2. In p-block elements the metallic character __________ down the group.

3. In p-block elements the orbital in the process of completion is __________.

4. Crystalline boron is a hard substance which is __________ in colour.

5. Out of all the elements of group IIIA, the highest Ionization potential is for __________.

6. Boron possesses close resemblance with __________.

7. Orthoboric acid is prepared by the acidification of hot concentrated solution of borax with calculated quantity of __________.

8. In the Hall-Berou.t process for producing aluminium the substance produced at the cathode is __________.

9. Hydrogen gas many be produced by the reaction of aluminium with a concentrated solution of __________.

10. The most widely distributed element in the earth’s crust after oxygen and silicon is __________.

11. Aluminium resists corrosion due to the formation of a coat of __________.

12. Hall’s Process is used for the production of __________.

13. Duralum is an alloy which contains Mg + Cu + __________ + Mn.

14. The group IV-A of the periodic table consists of __________.

15. Diamond has a high refractive index of __________.

16. At 700°C graphite burns in air to form __________.

17. Red lead is commonly known as __________.

18. __________ is the product of thermal decomposition of sodium bicarbonate.

19. Lead Monoxide is a yellow powder and also called __________.

20. Nitrogen, phosphorus, arsenic, antimony and bismuth are the members of the group __________.

21. All members of group VA exhibit maximum oxidation state of __________.

22. The shape of diamond is __________.

23. On an industrial scale nitric acid is prepared by __________.

24. Poisonous gas present in the exhaust fumes of car is __________.

25. The boiling point of nitric acid is __________.Url: http://www.pakchoicez.com | http://www.smsbundle.com | http://www.jazzbudget.com Page - 11




26. The freezing point of nitric acid is __________.

27. Oxygen, sulphur, selenium, tellurium and polonium are the members of group __________.

28. The first four members of the group VI-A are collectively called __________.

29. There are __________ electrons in the valence shell of elements of group VI-A.

30. The maximum valency of oxygen is __________.

31. Oxygen has __________ allotropic forms.

32. The transition temperature of sulphur is __________.

33. X-rays analysis shows that __________ sulphur consists of chains of sulphur atoms.

34. The purest H2S is obtained by passing vapours of sulphur and hydrogen over finely divided __________ at 450°C.

35. __________ was first prepared in the laboratory by Jabir Bin Hayyan.

36. __________ is called king of chemicals.

37. Lead Chamber process is used for the preparation of __________.

38. Contact Process is used for the production of __________.

39. __________ is called Oleum.

40. Freezing point of pure sulphuric acid is __________.

41. Dilute sulphuric acid dissolves many metals with the evolution of __________ and the corresponding sulphates are formed.

42. Formic acid is converted into carbon monoxide by the action of concentrated __________ and heating.

43. Gases such as oxygen, hydrogen, carbon dioxide, chlorine and sulphur dioxide are often dried by bubbling them through __________.

44. Concentrated sulphuric acid absorbs sulphur trioxide forming __________.

45. Carbon is oxidized to __________ in the presence of sulphuric acid.

46. In a process called pickling the metal sheets are soaked in __________ to remove rust or by chemical action.

47. Phosphine may be produced by the action of water on __________.

48. In the refining of petroleum, __________ is employed to remove tarry materials and sulphur compound.

49. In the Ostwald process, the substance which is used to oxidize NH3 is __________.

50. In the periodic table, halogens, namely fluorine, chlorine, bromine, iodine and astatine are placed in group __________.

51. The brown gas formed when metals reduce HNO3 is __________.

52. __________ is used as catalyst in the Contact Process.Url: http://www.pakchoicez.com | http://www.smsbundle.com | http://www.jazzbudget.com Page - 12




Chapter 5

Transition Elements

1. Annual production of antimony being mined in Pakistan is __________.

2. Annual production of Orchro being mined in Pakistan is __________.

3. Annual production of Chromite being mined in Pakistan is __________.

4. Annual production of manganese being mined in Pakistan is __________.

5. Transition elements other than Sc, Y and Ti have density above __________.

6. Due to d-d transition of electrons, Cu2+ ion appears __________ in colour.

7. The colour of Fe3+ ion is __________.

8. The colour of Fe2+ ion is __________.

9. The colour of Cr3+ ion is __________.

10. The colour of Mn3+ ion is __________.

11. The colour of Mn2+ ion is __________.

12. The colour of the fmale of potassium is __________.

13. The magnetic moment is related to the number of unpaired electron ‘n’ by the equation __________.

14. All the 3-d series elements show an oxidation state of __________ in addition to higher oxidation states except Sc.

15. The majority of transition metal’s ion complexes contain __________ ligands surrounding the central octrahedrally.

16. Copper is known since __________.

17. In Pakistan copper mines at Saindak in __________ were first discovered in 1962.

18. It is estimated that the Saindak mines will yield an annual production of __________ tones of copper from its sulphide ore for a period of 16 years on the commencement of production.

19. __________ percentage of total copper metal is obtained from sulphide ore.

20. The colour of copper is __________.

21. Copper becomes __________ when it is heated.

22. Copper melts at __________ °C.

23. Cu2O is __________ in colour.

24. The colour of CuO oxide is __________.

25. When copper is heated in air, then CuO + __________ are formed.

26. Bronze contains __________% Cu and 10% Sn.Url: http://www.pakchoicez.com | http://www.smsbundle.com | http://www.jazzbudget.com Page - 13




27. __________ is prepared in the laboratory by the action of dilute sulphuric acid on cupric oxide or cupric carbonate.

28. __________ is prepared by dissolving metallic silver in warm dilute nitric acid.

29. The highest common oxidation state of chromium is __________.

30. __________ is prepared in the laboratory by the addition of potassium chloride to hot concentrated solution of sodium dichromate.

31. __________ is used an an indicator in silver nitrate titration for the estimation of halide ions.

32. Potassium permanganate oxidizes acid in presence of dilute __________.

33. __________ is used as a disinfectant for purification of water.

34. __________ is used in bleaching paper pulp.

35. The rusting of iron is catalyzed by __________.

36. Conversion of any metal into its oxide by the action of environment is called __________.

37. Rusting of iron is an example of __________.

38. Aluminium resists the process of corrosion due to the formation of __________.

39. An alloy of iron, which contains chromium 18%, nickel 8% and carbon 0.18% is __________.

40. The black image on an exposed and developed photographic film is composed of __________.

41. In photography printing is accomplished by using an emulsion of __________.

42. All transition elements are __________.

43. Iron rust has the composition of __________.

44. When hydrated, Fe2+ ions are __________.

Chapter 6

Organic Chemistry

1. The main component of coal is __________.

2. When coal is heated in the absence of air, temperature ranging from __________, it is converted into coke, coal gas and coal tar.

3. The octane number of gasoline may also be increased by ading __________ as knoc inhibitor.

4. In Houdry process the breaking down of long-chain hydrocarbons is accelerated in the presence of a catalyst, made up of a mixture of __________.

5. The process of cracking takes place between temperature __________.

6. Molecular formula of ethers is __________.

7. Alkanes have general formula __________.





8. How many isomers can be obtained from the alkane C6H14.

9. Each alkane differs from its neighbours by __________.

10. The structural formula of ethane is __________.

11. Alkenes have general formula __________.

12. Alkyl halides have general formula __________.

13. On destructive distillation of 1000 kg of coal amount of coal tar formed is __________.

14. Natural gas consist of methane __________.

15. An alkane forms isomers if the number of least carbon atoms is __________.

16. The functional group of alkyle halids is __________.

17. The formula of alkane is __________.

18. The functional group o primary amines is __________.

19. The functional group of ether is __________.

20. The functional group of primary alcohol is __________.

21. The formula of methanol is __________.

22. The formula of ethanol is __________.

23. The formula of propanal is __________.

24. The formula of butanal is __________.

25. Formula of formic acid is __________.

26. The formula of acetic acid is __________.

27. The formula of propnoic acid is __________.

28. The formula of butyric acid is __________.

29. The formula of valeric acid is __________.

30. The formula of capric acid is __________.

31. Phenyl group is represented by __________.

32. The molecular formula of ethane is __________.

Chapter 7

Hydrocarbons

1. An example of alkane is __________.

2. __________ is the smallest hydrocarbon.





3. Natural gas consists of about __________% of methane.

4. A reaction catalyzed by the presence of __________ is called a photochemical reaction.

5. C2H2 reacts with HCl to produce __________.

6. __________ is used as catalyst in the oxidation of methane.

7. Methane reacts with superheated steam, on passing through hot tubes containing a __________ catalyst to yield carbon monoxide and hydrogen.

8. In methane H – C – H bond angles are __________.

9. The structural formula of ethylene is __________.

10. __________ is called ozone.

11. When ethene is passed through a dilute alkaline solution of KMnO4, the pink colour of the solution __________.

12. __________ reagent distinguishes ethylene from acetylene.

13. __________ polymerizes at 100 atmosphere pressure and 400°C to give polyethylene.

14. The polyethene produced in the presence of __________ and titanium tetrachloride as catalyst, shows improvement in its properties such as higher softening temperature, low permeability and greater rigidity.

15. __________ is called Dutch Liquid.

16. General formula of alkynes is __________.

17. __________ is called Acetylene.

18. Carboxylic acids combine with acetylene in the presence of __________ as catalyst, forming vinyl esters and the reaction is termed as Vinylation.

19. When a mixture of acetylene and nitrogen is submitted to an electric discharge, it forms __________.

20. When acetylene is passed through a copper tube at about 300°C it polymerizes to __________.

21. The brand of synthetic rubber is made by Polymerization of __________.

22. The process in which orbitals of different energies and shapes mix with each other to give equivalent hybrid orbital is called __________.

23. The sp3 signifies that each sp3 orbital is made up of s and p orbitals in the ratio of __________.

24. A molecule of methane has __________sigma bond(s).

25. A molecule of ethane has __________ sigma bond(s).

26. The sp3 hybridization occurs when carbon is bonded to __________ other atoms.

27. Sp2 hybrid orbitals are composed of s and p orbitals in the ratio of __________.

28. __________ bond is weaker.





Chapter 9

Organic Compounds

1. The general formula of alcohol is __________.

2. The general formula of aldehyde is __________.

3. Alcoholic fermentation is brought out by the action of __________.

4. The general formula of carboxylic acid is __________.

5. The general formula of esters is __________.

6. The general formula of ketone is __________.

7. The general formula of ether is __________.

8. The general formula of phenol is __________.

9. Methyl alcohol is used as the starting matrial in the manufacture of __________.

10. The formula of ethyl alcohol is __________.

11. To start the reversibility Estrification we use concentrated __________ used as absorbent of water produced during the reaction.

12. Dehydration means removal of __________.

13. The compound formed when silver powder is ehated with chloform is __________.

14. __________ is used as a fuel for internal combustion engines in many European countries and Brazil.

15. The formula of formaldehyde is __________.

16. The derivatives of carboxylic acids are obtained by replacing the –OH group of the carboxylic group with –OH and __________.

17. The formula of Fehling’s solution is __________.

18. The formula of Iodoform is __________.

19. Melting point of Phenol is __________.

20. Boiling point of Phenol is __________.

21. Phenol when treated with __________, yields both ortho and para sulphonic acids.

22. General formula of Grignard’s Reagent is __________.

23. The formula of Cyanogen chloride is __________.

24. The formula of Chloramine is __________.

MULTIPLE CHOICE QUESTIONS

Five Year Papers





1. On passing steam over red-hot coal we get __________.

(Water gas, Ethane, Carbonmonoxide)

2. ‘d’ and ‘f’ block elements are called __________.

(Heavy metals, Rare elements, Transition elements)

3. The correct formula of pyrosulphuric acid is __________.

(H2SO4, H2S2O7, H3S2O5)

4. Aqua regia is mixture of one part of __________ by volume and three parts of __________.

(H2SO4, H3PO4, HNO3, HCl)

5. Heavy hydrogen is also called __________.

(Proteum, Deuterium, Hydronium)

6. When boric acid (H3BO3) is heated of 140°C, it forms __________.

(Boric Acid, Pyroboric acid, Metaboric acid)

7. Photographic film is made of sheets of __________.

(Cellulose Acetate, P.V.A, Nylon)

8. C4H8 is a saturated hydrocarbon because it is __________.

(Cyclic, Open chain, Polymer)

9. n-Octane is __________ at room temperature.

(Gas, Liquid, Semi-solid)

10. The compound formed between an element A of group IIIA and an element B of group VIA has the formula __________.

(AB, A2, B3, A2B3)

11. The oxide formed by AI is __________.

(Acidic, Amphoteric, Basic)

12. Bakelite is a polymer of __________ and form aldehyde.

(Ethane, Methanol, Phenol)

13. The plastics, which can be heated only once, are known as __________ plastics.

(Perspex, Thermoplastic, Thermosetting)

14. The deficiency of __________ in the human body is the cause of diabetes.

(Insulin, Alamin, Ptyalin)

15. If the level of cholesterol increases in the blood serum, it causes __________.Url: http://www.pakchoicez.com | http://www.smsbundle.com | http://www.jazzbudget.com Page - 18




(Diabetes,Heart attact, High blood pressure)

16. The formula of baking soda is __________.

(NaHCO3, Na2CO3, Na2CO310H2O)

17. The formula of Plaster of Paris is __________.

(CaSO4.2H2O, 2CaSO4.H2O, (CaSO4)2H2O)

18. The atoms of the elements belonging to the same period of the Periodic table have __________.

(Same number of protons, same number of neutrons, same number of valence shells)

19. Sodium thiosulphate is used in photography because of its __________.

(Reducing power, Complex formation, Oxidizing behaviour)

20. The outer electronic configuration of copper is __________.

(4s14d10, 4s23d10, 4s13d10)

21. H2S solution in water is __________.

(Neutral, Acidic, Basic)

22. __________ is isomer of ethanol.

(CH3OH, CH3OCH3, C6H5OH)

23. Petroleum is a mixture of __________.

(Alkanes and alkenes, aromatic hydrocarbons, all of these)

24. Glucose is __________.

(Reducing sugar, oxidizing sugar, none of these)

25. Pentane shows __________.

(Two isomers, three isomers, four isomers)

Chapter 1

Periodic Classification of Elements

1. __________ elements have been discovered so far.

(100, 110, 120, 150)

2. so far 110 elements have been discovered. Out of these __________ elements are naturally occurring.

(100, 96, 92, 94)

3. __________ classified the then known elements into metals, non metals and their derivatives.

(Dobreiner, Al-Razi, Newlands, Mendeleeve)





4. In 1817, a German chemist, __________ made use of the idea of relationship between atomic weights and properties of elements for the classification of elements.


5. __________ presented the law of triads.


6. Dobreiner’s work led to the law of triads which states that __________.

(Atomic weight of any one lement was found to be approximately the mean of the other two elements of triad, Atomic weight of the middle element was found to be approximately the mean of the other two elements of a triad, Atomic number of any one element was found to be approximately the mean of the other two elements of a triad, Atomic number of the middle element was found to be approximately the mean of the other two elements of triad)

7. The law of octaves was given by __________.

(Dobreiner, Al- Razi, Newlands, None of these)

8. Law of octaves states that __________.

(The properties of every 6th element from the given one were similar to the first, the properties of every 9 th

element from the given one were similar to the first, the properties of every 8th element from the given one were similar to the first, the properties of every 7th element from the given one were similar to the second)

9. “Physical and chemical properties of elements are periodic functions of their atomic weight.” This is called __________.

(Dobereiner’s Law of Triads, Newlands’ Law of Octaves, Mendeleev’s Periodic Law, None of these)

10. Lother Meyer arranged the elements in order of their increasing atomic weights and found that __________.

(Physical propertis of the elements were the periodic function of their atomic weights, chemical properties of the elements were the periodic function of their atomic number, physical properties of the elements were the periodic function of their atomic number, chemical properties of the elements were periodic function of their atomic weights)

11. Mendeleev’s Periodic table was based on __________.

(Atomic number, Atomic mass, Atomic volume, Electronic Configuration)

12. Mandeleev formulated a rule for the classification of elements and concluded that __________.

(Physical and chemical properties of the elements are periodic functions of their atomic numbers, physical and chemical properties of the elements are periodic functions of their atomic weights, physical properties of the elements are periodic function of their atomic weights, Chemical properties of the elements are periodic functions of their atomic numbers)

13. Modern Classification of elements is based on __________.

(Doberiner’s law of Triads, Newlands’ law of Octaves, Mendeleev’s Periodic Table, None of these)

14. Excluding H and He, the smallest element in the periodic table is __________.

(Lithium, Fluorine, Cesium, Iodine)





15. “Physical and chemical properties of elements are the periodic functions of their atomic numbers.” This is called __________.

(Law of Triads, Law of Octaves, Periodic Law, None of these)

16. Moseley’s work led to the periodic law, which states that __________.

(the number of the electrons in the 1s energy level increases as the atomic number increases, The properties of the elements are a periodic function of their atomic masses, The x-rays spectra of the elements are more complex than the optical spectra, The properties of elements are the periodic function of their atomic number)

17. A pair of elements in the same family in the periodic table classification is __________.

(Chlorine and carbon, calcium and aluminium, nitrogen and neon, sodium and potassium)

18. In the period, the elements are arranged in strict sequence in order of __________.

(Increasing charges in the nucleus, increasing atomic weight, increasing number of electrons in valence shell, increasing valency)

19. Most of the known elements are metals of __________ of periodic table.

(d-block, p-block, III-group, Zero block)

20. __________ reflects combining capacity of an element.

(Valency, atomic number, ionization energy, ionization potential)

21. As we move from left to right in second period of the periodic table, the gram atomic volume of the elements __________.

(Increases at a constant rate, remains unchanged, decreases, will change indefinitely)

22. The volume in cubic centimeters occupied by one gram atom of the element is called __________.

(Atomic Volume, Atomic weight, Mass number, None of these)

23. In a __________, atomic volume increases with atomic number, from top to bottom, as new shells are added up with increase in atomic number.

(Group, Period, Sub-group, None of these)

24. __________ of the following is a transition element.

(Ni, Rb, Al, As)

25. On moving from left to right across a period in the periodic table, the size of atom generally __________.

(decreases, increases, remains constant, decreases up to IV A group and then increases)

26. The amount of energy required to remove an electron from an atom of an element in the gaseous state I called __________.

(Ionization Potential, Ionization energy, Electron volt, both a and b)

27. Each vertical row of the periodic table includes elements with chemical characteristics that are in general __________.





(identical, similar, different, sometimes identical and sometimes differents)

28. The ionization energy __________ in a group from top to bottom with the increase in atomic size.

(Increases, decreases, remains constant, none of these)

29. The lowest ionization energies are found in the __________.

(inert gases, alkali metals, Transition elements, Halogens)

30. Ionization energy is lowest for __________.

(Inert gases, alkali metals, halogens, alkaline earth metals)

31. In the periodic table, the highest ionization energies are for __________.

(Halogens, Noble gases, Alkali metals, Chalcogens)

32. The atomic weight of an element divided by its density is called __________.

(Atomic mass, Atomic volume, Atomic density, Atomic number)

33. Elements in the same family __________.

(have same atomic number, have the same molecular weight, have similar chemical properties, constitute a group of elements with the same electronic configuration)

34. In a given period, the alkali metals have __________.

(smallest atomic size, lowest ionization energy, lowest density, highest electron affinity)

35. Of the following given elements __________ atom has the highest ionization energy.

(Be, F, N, Ne)

36. The value of ionization energy __________ in a period from left to right due to the decrease in atomic size.

(increases, decreases, remains constant, None of these)

37. __________ is the most electronegative element.

(Fluorine, Iodine, Oxygen, Sodium)

38. The unit of ionization energy is __________.

(Joule, Calorie, electron volt, none of these)

39. Of the following elements, __________ element has the highest first ionization potential.

(Boron, carbon, nitrogen, oxygen)

40. The unit of ionization potential is __________.

(Joule, joule per mole, calorie per mole, none of these)

41. In a period, the ensity of normal elements first __________ and then __________ after reaching a maximum value somewhere in the middle.





(Increases, decreases, remains constant, none of these)

42. Most of the known elements are __________.

(Rrystalloids, Metals, Metalloids, Non metals)

43. Melting and boiling points gradually __________ in a periodic table from left to right up to the middle.

(increases, decreases, remains constnt, none of these)

44. The electropositive elements form __________.

(acidic oxides, basic oxides, neutral oxides, none of these)

45. __________ of the following elements has the lowest first ionization energy.

(Na, F, I, Cs)

46. The electronegative elements form __________.

(Acidic oxides, Basic oxides, Neutral oxides, none of these)

47. __________ is the most volatile compound.

(HI, HCl, HBr, HF)

48. The ionization energy of nitrogen is more than oxygen because of __________.

(more attraction of electrons by the nucleus, more peneration effect, the extra stability of half filled p-orbitals, the size of nitrogen atom is smaller)

49. The elements of group IIA are called __________.

(Metals, Non-metals, Alkaline earth metals, Transition elements)

50. __________ ion has the largest radius.

(Al+3, Cl-, F-, O-2)

51. __________ atom has the smallest size.

(C, F, Li, Rb)

52. __________ of the following has highest first ionization energy.

(Br, Cl, F, I)

53. The most electropositive among the following elements is __________.

(Fe, Na, Cs, Pb)

Chapter 2

Hydrogen

1. Large amounts of atomic hydrogen are present in the atmosphere of __________.

(Earth, Sun, Moon, none of these)Url: http://www.pakchoicez.com | http://www.smsbundle.com | http://www.jazzbudget.com Page - 23




2. Hydrogen atom contains __________ electrons.

(1, 2, 3, 4)

3. During the electrolysis of water hydrogen is liberated at the __________.

(Anode, Cathode, Diode, none of these)

4. The atomic weight of hydrogen is __________.

(1.00, 1.008, 1.08, 1.800)

5. In nature hydrogen exists in __________.

(Gaseous state, Solid state, Liquid state, Plasma state)

6. __________ is the lightest gas.

(Nitrogen, Helium, Oxygen, Hydrogen)

7. Alkali metals do not exist in __________.

(Monoatomic, Diatomic, Triatomic, none of these)

Names and Formulae of Chemical Compounds

S.No Names Formulae/Chemical Names

1. Vitamin E Tocopherol

2. Vitamin B1 Thiamine

3. Vitamin B2 Riboflavin or Lactoflavin

4. Vitamin B5 Niacin

5. Vitamin B6 Pyridoxine

6. Vitamin12 Cyanocoalamine

7. Vitamin C Ascorbic Acid

8. Vitamin A Retinol

9. Vitamin D Calciferol

10. Bleaching Poweder CaOCl2

11. Gypsum CaSO4.2H2O

12. Borax/Tincal Na2B4O7.10H2O

13. Oleum H2S2O7

14. Lunar Caustic AgNO3





15. Chrome Yellow PbCrO4

16. Fuming Sulphuric Acid SO3 + H2SO4

17. Plaster of Paris CaSO4.1/2 H2O

18. White Lead Pb3 (OH) 2 (CO3) 2

19. Water Glass CO + H2

20. Hypo Na2S2O3.5H2O

21. Baking Soda NaHCO3

22. Chrome Red Pb2CrO5

23. Pyroboric Acid H2B4O7

24. Blue Vitriol CuSO4.5H2O

25. Copper Pyrite CuFeS2

26. Chromite FeO.Cr2O3

27. Hydrogen Chromate H2CrO4

28. Aluminium Carbide Al4C3

29. Metabolic Acid HBO2

30. Potassium Maganate K2MnO4

31. Nila Thotha CuSO4.5H2O

32. Surkh Kahi K2Cr2O7

33. Ferricyanide ion Fe(CN)63

34. Formic Acid H-COOH

35. Acetic Acid CH3-COOH

36. Propionic Acid CH3 – CH2 – COOH

37. Butyric Acid CH3 – CH2 – CH2 – COOH

38. Valeric Acid CH3 (CH2)3 - COOH

39. Capric Acid CH3(CH2) 4 – COOH

40. Methanoic Acid H – COOH

41. Dutch Liquid/Ethylene dichloride

C2H4Cl2





42. Grignard’s Reagent R – Mg – X

43. Cyanogen Chloride ClCN

44. Chloramine ClNH2

45. Wood Spirit/Wood Naphtha

CH3OH

46. Iodo Form CHI3

47. Carbolic Acid C6H5OH

48. Glycogen (C6H10O5)x

49. Calcium Super Phosphate Ca(H2PO4)2

50. Phosphorite Ca3(PO4)2

51. Wavelite 2AlPO4.Al(OH)3.9H2O

52. Apatite Ca3(PO4)2 CaF2

53. Diammonium Hydrogen Phosphate

(NH4)2HPO4

SCIENTIFIC REASONS

Give the scientific reasons of the following: (Answers in the end.)

1. Transition elements form complex compounds.

2. Nitric acid is a strong oxidizing agent.

3. Na+ ion is smaller than Na atom.

4. Sulphuric acid has higher boiling point and viscosity.

5. 4s orbital is filled prior to 3d but on ionization the 4s electrons are lost first.

6. Anhydrous CuSO4 is white while hydrous CuSO4 is blue.

7. The heat of hydration of Li+ ion is greater than Cs+ ion.

8. Diamond does not conduct electricity while graphite does.

9. Nascent hydrogen is more reactive than ordinary molecular hydrogen.

10. Elements of group IA and group IIA readily loses their valence electrons.

11. Transition elements are paramagnetic.

12. Melting and boiling point of IA group elements are very low.





13. Ligands are generally called Lewis base.

14. Bromine is displaced from its salts by chlorine.

15. (NH4)+ and H3O+ ions donot act as ligands though H2O and NH3 act as ligands.

16. The salts of alkaline earth metals are hydrated than alkali metal salts.

17. Zn(OH)2 is soluble in excess of NaOH solution.

18. Why do chromium (24) and copper (29) shows an electronic configuration which is out of order.

19. Assign reasons for formation of coloured ion in case of transition elements except zinc.

20. Ionization enthalpies of IIA group elements are higher than IA group elements.

21. Graphite is used as Lubricant.

22. Metallic character of Aluminium is greater than Boron.

23. Plastic sulphur is elastic.

24. Alkaline earth metals are harder than alkali metals.

25. Ordinary hydrogen called as molecular hydrogen.

26. Electropositively increases from top to bottom.

27. Transition elements show variable oxidation state.

28. Na+ ions are discharged at the cathode in preference to H+ in the manufacture NaOH in Castner Kelner cell.

29. Li+/Li couple has exceptionally high negative electrode potential.

Answers to Scientific Reasons

1. Transition elements have small highly charged ions and vacant d-orbitals of suitable energy. These vacant d-orbitals form coordinate bond by accepting lone electron pairs from ligands. This is the reason why transition elements form coordination compounds.

2. The oxidizing properties of nitric acid is due to the stability of its molecule and because nitrogen is present in its highest oxidation state, i.e. 5. The degree of oxidation depends upon the concentration of acid and nature of element.

3. The number of protons in Na+ ion are greater than the number of electrons due to which the nuclear attraction increases. And Na+

has one shell less than Na atom, because the last shell consists of only one electron, which is not present in Na+ ion. These are the reason due to which Na+ ion has smaller radii than Na atom.

4. Sulphuric acid has higher boiling point and viscosity due to the presence of hydrogen bonding which link the molecules in larger aggregates.

5. According to Aufbau principle and n+l rule, the sequence of filling in atomic orbitals in dependent on the value of n + l.





Since,

n + l for 4s = 4 + 0 = 4

and,

n + l for 3d = 3 + 2 = 5s

Therefore, electron goes in the orbital having lowest energy i.e. 4s. In the same way, the electron in 4s orbital have less energy, therefore they are lost first during ionization.

6. Hydrated CuSO4.5H2O contains 5 molecules of water of crystallization and water act as ligand. The lone pair of electron of water molecules influence the 3d orbital of Cu by splitting it into eg and t2g. Thus by absorbing visible light an electron can jump from lower energy set (t2g) to higher energy set (eg). In doing so some of the component wavelength of light is removed, so the remaining component wavelength of light reflected shows the blue colour. An hydrous CuSO4 is colourless due to the absence of water molecule.

7. The atomic size of Lithium is much smaller than that of Cesium, therefore its charge density is more. Due to more charge density, the electrons are attracted with a greater force of attraction. This is the reason more amount of heat is liberated when one mole of Li+ ion is dissolved in water. This is the reason why heat of hydration decreases down the group.

8. In diamond, each carbon atom is sp3 hyberidized and is strongly bonded to four other carbon atoms. It utilizes its four unpaired electrons in the formation of four covalent bonds. Since, it has no free electrons; it is a poor conductor of electricity.Whereas, in graphite, each carbon is sp2 hybridized and covalently linked with three other carbon atoms to give basic hexagonal ring. These hexagonal rings are 3.35 A° away from each other and are held together by weak Vander Waal’s forces. The fourth electron of each carbon forms delocalized p bonds, which are spread uniformly. This is the reason graphite conducts electricity.

9. Molecular hydrogen is composed of two atoms of hydrogen. They are held together by a covalent bond. The bond energy of this covalent bond is 104 kcal/mole. In order to be reactive, the molecular hydrogen needs an energy to over come the bonding energy i.e. greater than 104 kcal /mole. Whereas in case of atomic hydrogen no such condition is required. This is the reason why atomic hydrogen is more reactive.

10. The elements in group IA and and IIA have only one or two electron in their valence shell. As we move from right to left in the periodic table, the nuclear charge decreases, which increases the atomic size and reduces the force on valence electron. This is the reason why elements of group IA and IIA readily lose their electrons.

11. The paramagnetic property of an element depends upon the availability of free electrons. Many compounds of the transition elements are paramagnetic. This is because they have unpaired electrons in their d-orbitals, which becomes active in a magnetic field.

12. The elements of group IA have large atomic radii and small nuclear charges. This is the reason why melting point, boiling points are lower than other elements in the periods.

13. Ligands are atoms, molecules or ions that donate a lone pair of electron to metal and form coordinate bond with them. According to Lewis, bases are substances that donate a lone pair of electrons. This is the reason why ligands are called Lewis base.





14. The electronegativity of chlorine is greater than that of bromine. Because it decreases down the group. Since, chlorine is more electronegative than bromine, it displaces bromine from its salts.

15. In case of NH3, the central atom nitrogen contains a lone pair of electron, which it can donate to metal. Whereas incase of NH4

+, the central atom nitragen has already donated its lone pair to hydrogen so it does not act as ligand. Similarly H2O act as ligand but H3O+ does not act as ligand.

16. Hydration of cations depend upon the nuclear charge and ionic radii. Smaller the ionic radii, greater would be the nuclear charge and more the salt will show the tendency for hydration. Since, the alkali earth metals have a greater nuclear charge and a stronger electric field than the alkali metals, therefore, they are more hydrated than alkali salts.

17. Zinc hydroxide I an emphotric substance, i.e. it shows both acidic and basic properties. Therefore, when Zn(OH)2 is dissolved in excess of NaOH solution it does not precipitate out but forms a complex ion and redissolves.

Zn(OH)2 + 2NaOH [Zn(OH)4]-2 + 2Na+

Tetra Hydroxozincate18. 24Cr = 4s23d4 (4s13d5)

29Cu = 4s23d9 (4s13d10)

The half filled or completely filled orbitals are more stable than other wise filled orbitals. In case of Cromium the one electron of 4s orbital jumps into 3d orbital, as a result 4s and 3d orbitals are half filled and stabized. Similarly in copper one electron of 4s orbital jumps into 3d orbital, as a result 4s is half filled whereas 3d is completely filled.

Hence electronic configuration of Cromium (Cr) is 4s13d5 instead of 4s23d4 and configuration of copper (Cu) is 4s13d10 instead of 4s23d9.

19. The formation of coloured ion in case of transition elements can be explained by Crystal Field Theory. According to the theory (C.F.T) the bonding between ligand and a metal ion is electrostatic. The ligands surrounding the metal ion create an electrostatic field around its d-orbital. This field splits five degenerated d-orbitals into two sets with different energies.

The energy difference between two sets (eg and t2g) of d orbital is equivalent to a wavelength in a visible region. Thus by absorbing visible light, an electron may be able to move from lower energy set (t2g) to higher energy set eg of d orbitals. In doing so some of the component wavelength of white light is removed, so the remaining component wavelength of light reflected or transmitted shows the colour of ion.

Hence the colour of the ion is due to the half filled 3d orbital, the electron can jump from d orbital of lower energy by the absorption of small amount of energy of a particular wavelength in a visible region. Since in case of zinc, the 3d orbital is completely filled therefore the compounds of Zinc are white or colourless.

20. The ionization enthalpies IIA (alkaline earth elements) is higher than the corresponding ionization enthalpies of IA group (alkali metals0, because elements of IIA group has an extra nuclear proton which causes an increase in the electrostatic Beautiful force between the nucleus and the outer most electron.

21. In Graphite, each carbon is Sp2 hyberidized and covalently linked with three other carbon atoms to give basic hexagonal





ring. These hexagonal rings then form layers in graphite. These layers are 3.35 A° away from one another and held together by weak Vander Waal’s forces of attraction. Due to large inter planner distance (3.35A°), the layers slide easily over one another that is why it is soft and used as Lubricant.

22. The maximum capacity of electron accomodation of boron in its outer most shell is eight electrons and that of Aluminium is eighteen electron.

5B = 1s2, 2s2, 2p1

13Al = 1s2, 2s2, 2p6, 3s2, 3p1

It means electron population of aluminium is less than boron. Due to less electron population, the number of neighbouring atoms in the lattice increases, that is why metallic character of aluminium is greater than boron.

23. The plastic sulphur or g-sulphur is composed of long chains of sulphur atoms. The elasticity of plastic sulphur is due to uncoiling of long sulphur chains and then recoiling of chains by the release of tension.

24. The alkaline earth metals (II group metals) are appreciably harder than alkali metals (I group) because the presence of divalent cations in their metallic structure produce greater bonding forces.

25. Ordinary hydrogen exist as diatomic molecule (H2) therefore it is also known as molecular hydrogen.

26. The tendency of atom to give out electrons is known as electropositivity. Electropositivity is inversely proportional to ionization potential and electron population. Both the factors decreases down the group, hence electropositivity increases from top to bottom.

27. The transition elemenets show variable oxidation states in their compounds. This variation is due to the very small energy difference in between 3d and 4s orbitals. As a result, electrons of 3d as well as 4s takes part in the bond formation.

28. In castner-kellner cell, H+ ions are not easily discharged due to high voltage of H+ ion, on the contrary Na+ ions are easily discharged over mercury surface.

29. Li+/Li couple has exceptionally high negative electrode potential because of its large value for the hydration enthalpy which promotes oxidation of Li to form Li+ ion.

TRUE AND FALSE

1. PVC is a polymer of benzene.

2. Fructose is a reducing sugar.

3. The deficiency of vitamin C causes scurvy.

4. Methanol causes blindness.

5. Diamond is the hardest known substance in the world.

6. The properties of boronoxide are acidic.

7. Graphite is a good conductor of electricity.

8. The deficiency of vitamin A causes night-blindness.





9. Wurtz reaction can be used to prepare Methane.

10. Bakelite is polymer of phenol and alkyl halide.

11. The heat of hydration of Li+ ion is equal to that of Cs+ ion.

12. The molecule of H2S is non-linear.

13. CuSO4 in excess of NH3 forms Cu(OH)2.

14. Compounds have benzene ring are called aeromatic.

15. Polyethenes are the most common plastics.

16. Lead-containing paints are banned because of the high cost.

17. Na2CO3 decomposes on heating.

18. The atomic weights of isotopes are different because of the difference in the number of protons.

19. Gastric juice is pale yellow in colour.

20. Ascorbic acid is enzyme.

21. The main function of carbohydrates is to circulate blood.

22. The preparation of vegetable ghee is a dehydrohalogenation process.

23. There are eight periods and seven groups in the Periodic table.

24. Hydrated copper sulphate is a white crystalline solid.

25. Pure diamond is colourless.

26. The first transition series starts from scandium and ends at zinc.

27. Markownikoff’s rule is not applicable to alkynes.

28. Methylated spirit is ethanol containing some methanol.

29. A functional group is the most reactive part of the molecule.

30. Vitamins A.D.K are water-soluble vitamins.

31. Kerosene oil is a petroleum product.

Answers to True and False

Five Year Papers1. False 2. True3. True 4. True5. False 6. True7. True 8. False9. False 10. False11. True 12. False





13. True 14. True15. False 16. True17. False 18. False19. False 20. False21. False 22. False23. False 24. False25. True 26. True27. False 28. True29. True 30. False31. True 32.





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