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
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)
41.
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.
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.
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