Sulphuric Acid1. Sulphuric acid is a highly corrosive strong mineral acid with the molecular formula H2SO4.2. Sulphuricacid is a diprotic acid.3. Sulphuricacid has a wide range of applications. It is also a central substance in the chemical industry.

Uses of Sulphuric Acid1. Applications of sulphuric acid include1. manufacturing fertiliser1. manufacturing detergent1. manufacturing pesticide1. manufacturing synthetic fibre1. as electrolyte in lead-acid accumulator1. removing metal oxide1. manufacturing paint

Manufacturing Sulphuric Acid: The Contact ProcessSulphuric Acid is Manufactured in Industry1. Sulphuric acid, H2SO4is manufactured in industry through Contact Process.2. The raw materials used are sulphur, air and water3. The Contact process consists of four stages.

Stage 11. Molten sulphur is burnt in dry air to produce sulphur dioxide2. The gas produced is then purified and cooled.

S+O2SO23. Sulphur dioxide can also be produced by burning metal sulphide such as lead(II) sulphide or zinc sulphide in dry air.

2PbS+3O22PbO+2SO2

Stage 21. In a converter, sulphur dioxide and excess oxygen are passed through vanadium(V) oxide.2. vanadium(V) oxide act as catalyst to expedite the process.3. The optimum condition for maximum amount of product are as follow:3. Temperature: 450 500 C3. Pressure: 2 3 atm1. About 99.5% of the sulphur dioxide, SO2is converted into sulphur trioxide, SO3through this reversible reaction.

Stage 3Sulphur trioxide is dissolved in concentrated sulphuric acid to form oleum H2S2O7.

SO3+H2SO4H2S2O7

Stage 4The oleum, H2S2O7is then diluted with water to produce concentrated sulphuric acid, H2SO4in large quantities.

H2S2O7+H2O2H2SO4

Note:1. The two reactions in the third and fourth stages are equivalent to adding sulphur trioxide, SO3directly to water.

SO3+H2OH2SO42. However, this is not done in industry because sulphur trioxide, SO3reacts too violently with water.3. This produces a lot of heat and a large cloud of sulphuric acid, H2SO4mist.4. The mist is corrosive, pollutes the air and is difficult to condense.

Summary

Environmental And Health Issues Of Sulphur DioxideSulphur dioxide, SO2is one of the by-products of the Contact Process. It is one of the source of environmental pollution.

Acid Rain1. Sulphur dioxide (SO2) is the pollutant primarily associated with acid rain.2. Acid rain occurs when pH of the rain is between 2.4 and 5.0. This is due to the reaction of sulphur dioxide,SO2with rainwater.

SO2+H2OH2SO33. The negative effect of acid rains include3. corrosion of concrete building and metal structure.3. corrosion of monuments and statues made from marble3. causes erosion of top soil.3. killing aquatic life.

Health Effects1. SO2is an irritant when it is inhaled and at high concentrations may cause severe problems in asthmatics such as narrowing of the airways, known as bronchoconstriction.2. Asthmatics are considerably more sensitive to the effects of SO2than other individuals.

Sources of SO21. The principal source of SO2is from the combustion of fossil fuels in domestic premises and , more importantly, non-nuclear power stations.2. Other industrial processes such as manufacturing of sulphuric acid also contribute to the presence ofSO2inthe air.

Ammonia1. Ammonia is a compound of nitrogen and hydrogen with the formula NH3.2. It is a colourless gas with a characteristic pungent smell.3. Ammonia is a very important compound in industry.4. Although in wide use, ammonia is both corrosive and hazardous.

Uses of Ammonia1. The uses of ammonia include1. manufacturing nitrogenous fertilisers1. as cooling agent in refrigerator1. to prevent coagulation of latex1. as raw material to manufacture nitric acid (Ostwald process)1. to make explosive1. as cleaning agent to remove grease

Manufacturing Ammonia Haber Process1. Ammonia is manufactured in industries through Haber Process.2. In Haber process, nitrogen gas, N2from the air is mixedwith hydrogen gas, H2derived mainly from natural gas.3. The mixture is compressed to a high pressure of 200 atmosphere at a temperature of about 450C.4. Iron is used as catalyst to speed up the rate of reaction.5. Chemical equation below shows the reaction.N2(g) + 3H2(g)2NH3(g)6. About 98% of mixture are converted into ammonia, NH3.7. The unreacted nitrogen gas,N2and hydrogen gas,H2are recycled and passed back into thereactortogether with the new source of nitrogen gas, N, and hydrogen gas,H2.

Summary

Characteristics Of AmmoniaCharacteristics of Ammonia1. Ammonia gas can turn a moist red litmus paper to blue.2. As an alkali, ammonia can react with acid to form salt and water.ExampleH2SO4(aq) + 2NH3(aq) (NH4)2SO4(aq)HNO3(aq) + NH3(aq)NH4NO3(aq)H3PO4(aq) + 3NH3(aq)(NH4)3PO4(aq)3. Ammonia dissolve into water to form ammonium and hydroxide ion.NH3+ H2ONH4++ OH-4. The hydroxide ion can react with many kinds of positive ion to form precipitate.ExampleMg2++ 2OH-Mg(OH)2Fe2++ 2OH-Fe(OH)2Al3++ 3OH-Al(OH)2

Testing for Ammonia1. Ammonia is the only common alkaline gas, so it can be identified with moist red litmus paper turning blue.2. Concentrated ammonia when reacts with concentrated hydrochloric acid produces white fume.Ammonia gas + Hydrogen chloride gasammonium chlorideNH3(g) + HC1 (g)NH4C1

Manufacturing Nitric Acid Ostwald ProcessIntroduction1. Industrially, nitric acid is made by the catalytic oxidation of ammonia over heated platinum.2. Oxidising ammonia produces oxides of nitrogen which can then be dissolved in water to produce nitric acid.

Reaction1. Initially, nitrogen(II) oxide will be formed from the catalytic oxidation of ammonia using the transition metal platinum.Ammonia + Oxygen Nitrogen(II) Oxide + Steam4NH3(g) + 5O2(g) 4NO (g) + 6H2O (g)2. The nitrogen(II) oxide is rapidly cooled before combining with oxygen (from excess air) to form nitrogen(IV) oxide.2NO (g) +O2(g) 2NO2(g)3. The nitrogen(IV) oxide, mixed with excess air, is then allowed to react with water to form nitric acid.Nitrogen(IV) Oxide + Oxygen (air) + Water Nitric acid4NO2(g) + O2(g) + 2H2O (1) HNO3(aq)

Uses of Nitric Acid1. Most of the nitric acid made is used to make the all-important fertilisers, such as ammonium nitrate.2. Other uses of nitric acid include making explosive, like nitroglycerine, or TNT (trinitrotoluene), and making dyes. Modern dyes are azo dyes, which can be formed by the reduction of various nitro-compounds.

Alloy1. An alloy is a mixture of two or more metals mixed in a certain percentage.2. Most pure metals are weak and soft. The properties of pure metals can be improved by making them into alloys.3. Alloys are made to3. increase the hardness of metals.Example:Magnalium is made from aluminium and magnesium to improve the hardness of the pure metals but at the same time, maintaining their lightness.3. prevent the corrosion of metals.Stainless steel which can resist rusting is made by adding carbon, chromium and nickel to iron.3. improve the beauty and lustre of metals.Copper and antimony added to tin produces pewter, used to make decorative items.

Copper Based Alloy1. Examples of copper base alloy are1. Cupro-nickel1. Bronze1. Brass1. Most copper base alloy has shiny surface

Cupro-nickelComponent:Cu 75%, Ni 25%

Applications:Coins

BronzeComponent:Cu 90%, Sn 10%

Applications:Decorative items, medals, artwork, pots and pans

BrassComponent:Cu 70%, Zn 30%

Applications:Decorative items, electrical appliances, musical instruments, bell, nails, screw, pots

Iron Based Alloy1. Examples of iron base alloy are1. steel1. stainless steel1. manganese steel1. The iron base alloys are usually very hard

SteelComponent:Fe 99%, C 1%

Applications:Vehicles, ships, bridges, buildings

Stainless steelComponent:Fe73%, Cr 18%, Ni 8%, C 1%

Applications:Kitchen appliances, watches, machine parts, knives, forks, spoons

Manganese steelComponent:Fe 85%, Mn 13.8%, C 1.2%

Applications:Helmet, spring

Aluminium Bases Alloy1. Examples of aluminium base alloy are1. Duralumin1. Magnalium1. Aluminium has low density, hence the density of aluminium base alloy is also low.

DuraluminComponent:Al 95%, Cu 4%, Mg 1%

Applications:Aeroplane parts, electric cables, racing bicycles

MagnaliumComponent:Al 70%, Mg 30%

Applications:Tyre rim of racing cars, skeletal body of aeroplanes

Tin Based Alloy1. Examples of tin base alloy are1. pewter1. solder1. Most tin base alloy has shiny surface and low melting point.

PewterComponent:Sn 91%, Sb 7%, Cu 2%

Applications:Decorative items, souvenirs

SolderComponent:Sn 50%, Pb 50%

Applications:Welding and soldering work

Welding

(Soldering)

PolymerPolymer1. Polymer is a large molecule that is in the form of a long chain with a high relative molecular mass (RMM).2. It is made up of many smaller units called monomers, which are joined together through a process called polymerisation. Thus the monomer is actually the repetitive unit of a long polymer chain.3. There are two types of polymers:3. Natural polymers3. Synthetic polymers

Natural Polymers1. These occur naturally in living things. Some examples of natural polymers are:1. Natural rubber1. Protein in meat, leather, silk, hair and fur1. Carbohydrates in cellulose, starch and sugar1. Natural polymers are made up of carbon, hydrogen, nitrogen and oxygen.

Synthetic Polymers1. Synthetic polymer is a polymer that is manufactured in industry from chemical substances through the polymerisation process.2. Examples of synthetic polymers are:2. plastics2. synthetic fibres2. elastomers1. The two types of polymerisation are:3. polymerisation by addition3. polymerisation by condensation

Polymerisation1. Polymerisation is the process of joining together the large number of monomers to form a polymer.2. There are 2 types of polymerisation process2. polylerisation by addition2. polylerisation by condensation

Polylerisation by AdditionPolymerisation by addition involves monomers with >C = C< bonding, where the monomers join together to make a long chain without losing any simple molecules from it.

Polylerisation by Condensation1. Polymerisation by condensation involves the elimination of small molecules like water, methanol, ammonia or hydrogen chloride during the process.2. Examples of products of this process are terylene and nylon-66.

Examples of Synthetic PolymersExamples Of Synthetic Polymers - Plastics

1. Plastics are light, strong and do not react with any chemical substances, like acids and alkalis.2. They can be made into many shapes and sizes.3. They are also good insulators of heat and electricity.

Examples of Plastics:

Polythene (polyethylene)Structure

Monomer:EtheneProduced by polymerisation: AdditionUses:Plastic bags containers and cupsAdvantages: light and strong

Polyvinyl chloride or PVC (polychloroethene)Structure

Monomer:ChloroetheneProduced by polymerisation: AdditionUses:Raincoat, Pipes to insulate electric wiresAdvantages:can be coloured; heat resistant

Polystyrene (polyphenylethene)Structure

Monomer:PhenyletheneProduced by polymerisation: AdditionUses:Packaging materials, children toys, ball-point pens, as heat and electric insulatorsAdvantages:light and strong

Perspex (polymethyl 2-methyl propenoate)Structure

Monomer:Methyl-2-methylpropenoateProduced by polymerisation: AdditionUses:Aeroplane window panes, Lenses, car lamp coversAdvantages:light, strong, translucent, stable towards sunlight

PolypropeneStructure

Monomer:PropeneProduced by polymerisation: AdditionUses:Plastics, Bottles, plastic tables and chairsAdvantages:strong and light

Teflon (polytetrafluoroethene or PTFE)Structure

Monomer:TetrafluoroetheneProduced by polymerisation: AdditionUses:To make non-sticky pots and pansAdvantages:hard, can withstand high temperatures and corrosives chemicals

Examples Of Synthetic Polymers - Synthetic Rubber1. Synthetic rubber is an elastomer or polymer which regains its size original shape after being pulled or pressed. [Natural rubber is an elastomer too.]2. Examples of synthetic rubber are neoprene and styrene-butadiene(SBR).

NeopreneStructure

Monomer:ChloropreneProduced by polymerisation: AdditionUses:to make rubber gloves and to insulate electric wires.

Styrene-butadiene or SBRStructure

Monomer:Styrene and butan-1,3-dieneProduced by polymerisation: AdditionUses:to make tyres, soles of shoes and mechanical belts.

Examples Of Synthetic Polymers - Synthetic Fibre1. Nylon and terylene are synthetic fibres which undergo the condensation polymerisation process.2. These fibres resemble natural fibres but more resistant to stress and chemicals, and more long-lasting.3. In both cases, water is eliminated during the polymerisation process.

NylonStructure

Monomer:Produced by polymerisation: CondensationUses:To make umbrellas, carpets, comb, curtains, nylon string and rope, socks, toothbrush and so on.

TeryleneStructure

Monomer:Produced by polymerisation: CondensationUses:To make fishing nets, clothes (quick-dry, non-iron), cassette and video tapes.

Issue In Using Synthetic Polymers1. Synthetic polymers have multiple uses in daily life because of the following properties:1. Light and strong1. Relatively cheap1. Withstand corrosion and chemical reaction1. Withstand action of water1. Non-flammable1. Can be colour easily1. Easily mould to shape1. Synthetic polymers are also used to replace natural polymers such as cotton, silk and rubber.1. However, synthetic polymers cause environmental pollution.3. Most polymers are not biodegradable . Disposal of polymers has resulted in environmental.3. The open burning of plastics gives rise to poisonous and acidic gases like carbon monoxide, hydrogen chloride and hydrogen cyanide. These are harmful to the environment as they cause acid rain.3. Burning of plastics can also produce carbon dioxide, too much of this gas in the atmosphere leads to the `greenhouse effect'.1. These problem can be overcome by the following ways:4. Recycling polymers: Plastics can be decomposed by heating them without oxygen at 700C. This process is called pyrolysis. The products of this process are then recycled into new products.4. Inventing biodegradable polymers: Such polymers should be mixed with substances that can be decomposed by bacteria (to become biodegradable) or light (to become photodegradable).

Glass And Ceramics1. The most important component of glass and ceramics is silica ( silicon(IV) dioxide, SiO2).2. Both glass and ceramic have the following properties:2. Hard and brittle2. Do not conduct heat electricity2. Inactive towards chemical reactions2. Weak when pressure is applied2. Can be cleaned easily

Glass1. It is a mixture of two or more types of metallic silicates but the main component is silicon(IV) dioxide.2. Glass has the following properties:2. Transparent and not porous2. Inactive chemically2. Can be cleaned easily2. Good insulators of heat and electricity2. Hard but brittle2. Can withstand compression but not pressure

Soda lime,glass

Composition:SiO2 70%, Na2O 15%, CaO 10%, Others 4%

Properties:

1. Low melting point (700C)2. Moldable into shapes3. Cheap4. Breakable5. Can withstand high heat

Uses:Glass containers, Glass panes, Mirrors, Lamps and bulbs, Plates and bowls Bottles

Lead glass (crystal)

Composition:SiO2 70%, Na2O 20%, PbO 10%

Properties:

1. High density and refractive index2. Glittering surface3. Soft4. Low melting point (600C)

Uses:Containers for drinks and fruit, Decorative glass and lamps, Crystal glassware, Lenses for spectacles

Borosilicate glass (Pyrex)

Composition:SiO2 80%, B2O3 13%, Na2O 4%, AI203 2%

Properties:

1. Resistant to high heat and chemical reaction2. Does not break easily3. Allows infra-red rays but not ultra-violet rays

Uses:Glass apparatus in laboratories, Cooking utensils

Fused silicate glass

Composition:SiO2 99%, Other - 1%

Properties:

1. High melting point (1700C)2. Expensive3. Allows ultraviolet light to pass through4. Difficult to melt or mould into shapeCeramics1. Ceramic is a substance that is made from clay and hardened by heat in a furnace maintained at a high temperature.2. Clay is composed of aluminosilicate with sand and iron(III) oxide as impurities.3. Examples of ceramics include3. Tiles3. Cement3. Bricks3. porcelain

1. The properties of ceramics include the following:1. The differences between the properties of ceramics, metals and non-metals are given below

PropertyMetalsNon-metalsCeramic

HardnessHard but malleable and ductileSoft and brittleHard but brittle

DensityHighLowAverage

Melting pointHighLowVery high

Resistance to heatHighLowVery high

Heat andElectrical conductivityGoodconductorGoodinsulatorGoodinsulator

Chemical reactionsCorrodesCorrodesStable, does not corrode

Comparing Glass And Ceramic

Common Properties of Glass and Ceramics

1. Hard2. Strong but brittle3. Chemically inactive4. Poor conductor of heat and electricity5. High melting point heat resistant6. Cannot be compressed easily

Uses Of Glass And Ceramics

Photochromic Glass1. Photochromic glass is very sensitive to light.2. It darkens in the presence of bright light and lightens when the amount of sunlight lessens.

Conductive Glass1. Conducting glass is a type of glass which can conduct electricity. It is obtained by coating a thin layer of a conducting material around the glass, usually indium tin(IV) oxide.2. It is used in the making of Liquid Crystal Display (LCD)

Car Engine Block1. When clay is heated with magnesium oxide, the ceramic that is produced has a high resistance to heat.2. This material is used to build the engine blocks in cars as they can withstand high temperatures.

Superconductors1. Superconductors are electrical conductors which have almost zero (0) electrical resistance. Therefore, this conductor minimises the loss of electrical energy through heat.2. Yttrium barium copper oxide is a type of ceramic superconductor3. Superconductors are used to make magnets which are light but thousands of times stronger than the normal magnet.

Composite Materials1. Composite materials are substances which contain 2 or more materials that combine to produce new substances with different physical properties from the original substances.2. Some composite materials and their components are:

Reinforced ConcreteComponent: Concrete (cement, sand, stones), steel

1. Ordinary concrete is strong but heavy. Concrete pillars must be big to support the weight. They take up space and cannot withstand stress for example from earthquakes.2. Steel pillars are too expensive and can rust.3. Reinforced concrete, containing steel rods in the concrete pillars, can make them stronger and able to support larger loads. It also does not rust.

Optical FibreComponent: SiO2, Na2CO3, CaO

1. This is a fine transparent glass tube that is made of molten glass.2. In telecommunications, light has replaced electrons as the transmitter of signals. This light transmits signals through optical fibre.3. Optical fibre is also used in the medical field as3. laser to do operation3. endoscope to examine the internal organs of patients

Photochromic GlassComponent: glass, AgCl (or AgBr

1. Photochromic glass is very sensitive to light.2. It darkens in the presence of bright light and lightens when the amount of sunlight lessens.

FibreglassComponent: Fibreglass and polyster resin

1. Fibre glass is obtained by adding a polyester resin to molten glass. It cannot be compressed easily and is more tensile than the original materials.2. Fibre glass is light, withstands corrosion, can be cast into different shapes, is impervious to water, not very flammable, not brittle and stronger than even steel.3. It is used to make racquets, construction panels, electrical appliances, pipes, and water tanks.

SuperconductorComponent: Ytrium oxide (Y2O3), BaCO3, CuO

1. Superconductors are electrical conductors which have almost zero (0) electrical resistance. Therefore, this conductor minimises the loss of electrical energy through heat.2. Yttrium barium copper oxide is a type of ceramic superconductor3. Superconductors are used to make magnets which are light but thousands of times stronger than the normal magnet.