The document discusses the manufacture of sulphuric acid, ammonia, alloys, synthetic polymers, glass and ceramics. Sulphuric acid is manufactured through the contact process involving combustion of sulphur to produce sulfur dioxide, oxidation of sulfur dioxide to sulfur trioxide and absorption of sulfuric acid. Ammonia is manufactured through the Haber process involving reaction of nitrogen and hydrogen gases at high pressure and temperature over an iron catalyst. Common alloys include steel, brass and bronze which have improved properties compared to pure metals. Synthetic polymers are long chain molecules formed by polymerization and include plastics such as polyethylene, PVC and nylon. Glass is made mainly from silica while ceramics such

3. The raw materials for the manufacture of sulphuric acid in Contact process are sulphur,oxygen and water.

4. There are three stages in Contact process:

5. a)Stage 1:Combustion of sulphur(To produce sulphur dioxide gas)

6. -Molten sulphur is burnt in excess air to produce sulphur dioxide gas.

7. S(l) + O2(g) → SO2(g)

8. -Sulphur dioxide gas is also produced by heating sulphide ores like iron persulphide, FeS2 in excess air.

9. 4FeS2(s) + 11O2(g) → 2Fe2O3(s) + 8SO2(g)

10. -The mixture is then purified,dried and cooled.

11. b)Stage 2:Oxidation of sulphur dioxide gas(To produce sulphur trioxide gas)

12. -Sulphur dioxide and excess oxygen gas are passed over Vanadium(V) oxide, V2O5 catalyst at 450C - 550C and pressure of 1 atmosphere.

13. 2SO2(g) + O2 ⇋ 2SO3(g)

14. △H = -197kJ mol-1

15. -99.5% of sulphur trioxide gas is produced via a reversible,exothermic reaction.

17. SO3(g) + H2O(l) → H2SO4(aq)

19. a) the burning of sulphur in the Contact process.

20. b) the extraction of metals from their sulphide ores.

21. c) the burning of fossil fuels (petroleum,natural gas,coal).

22. Inhaling sulphur dioxide causes coughing, chest pain, shortness of breath, bronchitis and lung diseases.

23. When sulphur dioxide dissolves in rainwater, it forms sulphurous acid and causes acid rain.

24. SO2(g) + H2O(l) → H2SO3(aq)

25. Sulphur dioxide can be oxidised to sulphur trioxide when:

26. a) reacted with nitrogen dioxide.

27. SO2(g) + NO2(g) → SO3 (g) + NO(g)

28. b) catalysed by dust particles or water droplets.

29. 2SO2(g) + O2(g) ⇌ 2SO3(g)

30. The sulphur trioxide produced dissolves in rainwater; it forms sulphuric acid and causes acid rain.

31. SO3(g) + H2O(l) → H2SO4(aq)

32. Acid rain produced may lead to the following effects:

33. a) Acid rain corrodes the buildings and statues made of limestone. Limestone reacts with sulphuric acid to form calcium sulphate.

34. CaCO3(s) + H2SO4(aq) → CaSO4(s) + CO2(g) + H2O(l)

35. b) Acid rain corrodes the metallic structures. Iron reacts with sulphuric acid to form iron (II) sulphate.

36. Fe(s) + H2SO4(aq) → FeSO4(aq) + H2(g)

37. c) Acid rain reduces the pH value of the soil as well as leaches out the minerals and nutrients in the land. Plants die of malnutrition and diseases, thus destroying the trees in forests.

38. d) Acid rain increases the acidity of water in lakes and rivers. Aquatic organisms cannot survive in acidic water, thus causing the death of aquatic organisms.

39. Emission of sulphur dioxide gas during the Contact process can be removed by reacting the gas with:

40. a) ammonia or ammonium hydroxide to produce ammonium sulphate (used as a fertilizer)

42. The major use of ammonia is in the production of nitrogenous fertilisers.

43. Ammonia is used in the manufacture of nitric acid via Ostwald process.

44. There three stages in Ostwald process:

45. a)Stage 1:

46. (To produce nitrogen monoxide gas)

47. Ammonia is oxidised to form nitrogen monoxide and water.

48. 4NH3(g) + 5O2(g) ⇌ 4NO(g) + 6H2O(l)

49. △H = -1170 kJ mol-1

50. b)Stage 2:

51. (To produce nitrogen dioxide gas)

52. Nitrogen monoxide reacts with excess oxygen to form nitrogen dioxide.

53. 2NO(g) + O2(g) → 2NO2(g)

54. c)Stage 3:

55. (To produce liquid nitric acid)

56. Nitrogen dioxide reacts with oxygen and water to form nitric acid.

57. 4NO2(g) + O2(g) + 2H2O(l) → 4HNO3(aq)

58. 2) Properties of ammonia

59. The physical properties of ammonia are as follows:

60. The chemical properties of ammonia:

61. a) It reacts with hydrogen chloride gas to form dense white fumes of ammonium chloride.

62. HCl(g) + NH3(g) → NH4Cl(s)

63. b) It neutralizes various acids to form ammonium salts.

65. The raw materials for the manufacture of ammonia in the Haber process are hydrogen and nitrogen gases.

66. Nitrogen gas is obtained from fractional distillation of liquefied air.

67. Hydrogen gas is obtained from natural gas.

68. a) Methane, CH4 in natural gas reacts with steam in the presence of nickel catalyst at 700C.

69. CH4(g) + H2O(g) → CO(g) + 3H2(g)

70. b) Carbon monoxide in the mixture is then oxidised to carbon dioxide using steam and iron catalyst.

71. CO(g) + H2O(g) → CO2(g) + H2(g)

72. The ratio of 1 mole of nitrogen gas to 3 moles of hydrogen gas is passed through a reactor.

73. The mixture is compressed to a high pressure of 200 atmospheres at 450C - 550C and catalysed by iron to speed up the reaction.

74. N2(g) + 3H2(g) ⇌ 2NH3(g)

75. △H = -180 kJ mol-1

76. Ammonia formed is liquefied and separated from the unreacted nitrogen and hydrogen gases. These gases are passed back into the reactor for further reaction.

78. The main characteristics of glass are:

79. a)Hard but brittle

80. b)Chemically inert

81. c)Transparent and impermeable(non-porous)

82. d)Withstand compression

83. e)Good heat and electrical insulatorsType of glassCompositionPropertiesUsesFused glassSiO2: 100%TransparentHigh melting pointGood heat insulatorLensTelescope mirrorsLaboratory apparatusSoda-lime glassSiO2: 75%Na2O:15%CaO: 9%Other:1%Low melting point, easily molded into desired shape and sizeLow resistant to chemical attacksBrittleDrinking glass, bottlesElectric bulbsWindow glassBorosilicate glassSiO2: 78%B2O3: 12%Na2O: 5%CaO: 3%Al2O3:2%Resistant chemical attack and durableHigh melting pointGood insulator to heatCooking utensilsLaboratory glassware such as conical flaks and boiling tubeLead crystal glass (flint glass)SiO2: 70%Pbo/PbO2:20%Na2O: 10%High refractive indexHigh densityAttractive glittering appearanceLenses and prismsDecorative glassware and art objectImation jewellery 2) Ceramics Traditional silicate ceramics are made by heating aluminosilicate clay such as kaolin to a very high temperature. Ceramics have many special properties that make them one of the most useful materials in our everyday life. That: Are hard, strong but brittle Have high melting point and remain stable at high temperature Are heat and electric instrument Are resistant to corrosion and wear Are chemically not reactive Do not readily deform under stress Ceramic play important role in our daily life. They are uses as Construction materials Decorative items Electrical insulator MaterialsMelting point/ °CDensity/G cm-3Elastic modulus/ GPaHardness/ mohsOxide ceramicAlumina,AL2O3Beryllia, BeOZirconia, ZiO2054257427103.973.015.68380370210988Non-oxide ceramicsBoron carbide,B4C3Silicon nitride, Si3, n42350283019002.503.163.17280400310999MetalsAluminiumSteel66015152.707.867020535