Chapter 9: Manufactured Substances in

Industry

School’s name: SMK (P) St. George, Penang

Name: Suhaila Bt. Hj. Mohamed

Class: 4 Mutiara

Teacher’s name: Mr. Teo Seah Ping

Year: 2012

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CONTENT

No. Title Page no.1.

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A. Sulphuric acid- Uses of sulphuric acid- Manufacture of sulphuric acid- Sulphur dioxide and environment pollution

B. Ammonia and its salts- Uses of ammonia- Properties of ammonia- Manufacture of ammonia in industry- Ammonium fertilisers

C. Alloys- Arrangement of atoms in metals- What are alloys?- Composition, properties, uses of alloys

D. Synthetic polymers- What are polymer?- Synthetic polymers in daily life

E. Glass and ceramics- What are glass?- Ceramics

F. Composite material- What are composite materials?

References

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A. SULPHURIC ACID

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SULPHURIC ACID (H 2 SO 4 )

# USES OF SULPHURIC ACID

1. Sulphuric acid is used to produce chemical fertilizer such as ammonium sulphate and potassium sulphate, which are highly soluble in water and can be easily obsorbed by plant.2. Car batteries contain sulphuric acid which is used as the electrolyte.3. Sulphuric acid also used in the making of artificial silk-like fibres and rayon.4. Chemical like paints, dyes and drug use sulphuric acid as one of their component materials.

Manufacture of detergents Manufacture of fertilizer

Leather tanning Manufacture of paint

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# MANUFACTURE OF SULPHURIC ACID

1. Sulphuric acid is manufactured in industry though contact process2. The process contain three stage

STAGE1: Production Of Sulphur Dioxide From Sulphuri. Combustion of sulphur or sulphide ores in the air produce sulphur dioxide SO2.

S(s) + O2(g) SO2(g) sulphur

ii. Sulphur dioxide is dried and purified.

STAGE2: Production Of Sulphur Trioxide From Sulphur Dioxidei. The purified sulphur dioxide SO2 and excess air are passed over vanadium(V)oxide V2O5 at controlled optimum condition optimum condition to produce sulphur trioxide SO3.

2SO2 (g) + O2(g) 2SO3(g)

ii. The optimum used area) Temperature:450-500°Cb) Pressure: 2-3 atmospheresc) Catalyst: Vanadium(V) oxide

iii. Under controlled optimum conditions, 98% conversion is possible. Sulphur dioxide and oxygen that have not reacted are allowed to flow back again over the catalyst in the converter.

STAGE3: Conversion of trioxide to sulphuric acidi. Sulphur trioxide SO2 is dissolved in concentrated sulphuric acid H2SO4 to form oleum H2S2O7 which is then diluted with water to form sulphuric acid H2SO4.

SO3(g)+H2SO4(l) H2S2O7(l) Oleum

H2S2O7(l)+ H2O(l) 2H2SO4(aq)

ii. The two reactions in stage3 are equivalent to adding sulphur trioxide directly into water.

SO3(g)+H2O(l) H2SO4(aq)

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iii. The addition of sulphur trioxide directly into is not carried out because the reaction is vary vigorous; a lot of heat is given off. As a result, a large cloud of sulphuric acid fumes is produced, which is corrosive and causes severe air pollution.

The Contact Process

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# SULPHUR DIOXIDE AND ENVIRONMENTAL POLLUTION 1.Sulphur dioxide is one of the by-product of contact process. It is a colourless andpoisonous gas with a vary pungent smell.2.Sulphur dioxide which escape into the air causes air pollution. 3.Sulphur dioxide is an acidic which dissolves in water to form sulphurous acidic, H2SO3. In the atmosphere, sulphur dioxide dissolve in water droplets to form sulphurous acidic.

SO2(g) + H2O(l) H2SO3(aq)

4.Oxidation of sulphur acid by oxygen produce sulphuric acid, H2SO4, which falls to theearth as acid rain. Sulphur trioxide is also easily oxidised in the air to form sulphurtrioxide. Sulphur trioxide dissolve in rainwater to produce sulphuric acid.

SO3(g) + H2O(l) H2SO4(aq)

Acid rain and environmental pollution

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B. AMMONIA AND ITS SALTS

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AMMONIA AND ITS SALTS (NH 3 )

# USES OF AMMONIA

1.Ammonia that is produce commercially has many uses.2.It uses:i) In the manufacture of chemical fertilizers such as ammonium sulphate, ammonia nitric, ammonia phosphate and urea.ii) To manufacture nitric acid and explosive.iii) In the making of synthetic fibre and nylon.iv) As a degreasing agent in aqueous form to remove greasy stains in the kitchen.

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# PROPERTIES OF AMMONIA GAS

1.The physical properties of ammonia gas include the following:i) It colourless and has a pungent odour.ii) It is vary soluble in water and form a weak alkaline solution.iii) It less dense then water.iv) It easily liquified (at about 35.5°C) when cool.2.The chemical properties of ammonia gas:a) Ammonia gas dissolves in water to form a weak alkali.

NH3(g) + H2O(l) NH4+(aq) + OH-(aq)

b) The presence of hydroxide icon causes the aqueous solution to become alkaline. Thus aqueous ammonia solution:i) Turns red litmus paper blue.ii) Reacts with acid to form only salt and waterin neutralization reaction.

NH3(aq) + HCI(aq) NH4CI(aq)

2NH3 + H2SO4(aq) (NH4)2SO4(aq)

iii) Reacts with solution of metallic cations to produce precipitates.

Fe²+(aq) + 2OH(aq) Fe (OH)2(s)(Form ammonia solution) Dirty green precipitate

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# MANUFACTURE OF AMMONIA IN INDUSTRY 1. Ammonia is manufacture on a large scale in industry through the haber process. In this process, ammonia is formed form direct combination of nitrogen and hydrogen gas in the volume ratio 1:3.2. The gas nitrogen obtain form the fractional distillation of liquefied air. The hydrogen gas is obtained form the cracking of petroleum or from the catalysed reaction of natural gas, CH4, with steam.

CH4(g) + H2O(g) CO(g) + 3H2(g)

3.The mixture of nitrogen and hydrogen gases is passed over an iron catalyst undercontrolled optimum condition as below to form ammonia gas.i)Temperature: 450-500°Cii)Pressure: 200-500 atmospheresiii)Catalyst used: Iron fillings

N2(g) + 3H2(g) 2NH3(g)

4.Under these control optimum condition, only 15% of the gas mixture turn into ammonia gas. The nitrogen and hydrogen that have not reacted are then flow back over the catalyst again in the reactor chamber.5.The ammonia product is then cooled at a low temperature so that it condenses into a liquid in the cooling chamber.

The Haber Process

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# AMMONIUM FERTILIZERS 1. Nitrogen is required in large amount by plant to make proteins which are necessary for growth and cell repair.2. Most plant are not able to get a nitrogen supply directly from the air although it is abundant in the air (78%). Plants can only absorb soluble nitrogen compounds from soil through their roots.3. The nitrogen compounds are usually soluble nitric salt, ammonia and ammonia salt which are manufacture as chemical fertilizer.4. Reactions of ammonia with acids produce ammonium fertilizers.

NH3(aq) + HNO3(aq) NH4NO3(aq) Ammonium nitrate

3NH3(aq) + H3PO4(aq) (NH4)3PO4(aq) Ammonium phosphate

2NH3(aq) +H2SO4(aq) (NH4)2SO4(aq) Ammonium sulphate

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C. ALLOYS

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ALLOYS

# ARRANGEMENT OF ATOMS IN METALS 1. The atom of pure metals are packed together closely. This causes the metal to have a high density2. The forces of attraction between atoms (metallic bonds) are strong. More heat energy is needed to overcome the metallic bond so that the atoms are further apart during the melting. This is why metals usually have hight melting point.3. Heat energy can be transferred easily from one atom to the next by vibration. This make metal good conduct of heat.4. The freely moving outermost electrons within the metal’s structure are able to conduct electricity. Metal are, therefore, good electrical conductors.5. Since atoms of pure metal are of the same size, they are arranged orderly in a regular layered pattern. When a force is applied to metal, layer of atom slide easily over one another. This make pure metals soft, malleable and ductile.

Metals are ductile

Metals are malleable

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# WHAT ARE ALLOYS 1. Pure metal are usually too soft for most uses. They also have a low resistance tocorrosion. They rush and tarnish easily.2. To improve the physical properties of metal, a small amount of another element(usually metal) is added to form another an alloy.3. An alloy is a mixture of two or more metals (something non-metal) in a specificproportion. For example:a) Bronze (90% of copper and 10% of tin)b) Steel (99% of iron and 1% of carbon)4.The purposes of making alloys include the following:a) Increase the strengthi. Pure iron is soft and vary malleable. When a small amount of carbon is added toiron, an alloy, steal is formed. The more carbon is added, the stronger the steelbecomes.ii. Pure aluminium is light but not strong. With a small amount of copper andmagnesium are added to aluminium, a strong, light and durable alloy callduralumin is produced.

b)Improving the resistance to corrosioni. Iron rust easily but stainless steel which contains 80.6% of iron, 0.4% of carbon,18% of chromium and 1% of nickel does not rush. These properties makestainless steel suitable for making surgical instrument and cutlery.ii. Pure copper tarnish easily. When zinc (30%) is added, the yellow alloy which isknown as brass develops a high resistance to corrosion.

c) Enhancing the appearancei. Pewter, an alloy of tin (97%), antimony and copper is not only hard but also hasa more beautiful white silvery appearance.ii. When copper is mixed with nickel to form cupronickel, an alloy that has anattractive silvery, bright appearance is formed which is suitable for making coins.

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The composition, properties and uses of some alloys

The formation of alloy

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D. SYNTHETIC POLYMERS

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SYNTHETIC POLYMERS

# WHAT ARE POLYMER 1.Molecule that consist of a large number of small identical or similar units joined together repeatedly are called polymer.2.The smaller molecules that make up the repeating unit in polymer are caller monomer.3.The process of joining together a large number of monomers to form a long chainpolymer is called polymerisation.

Formation of a polymer

4.Polymer can be naturally occurring or man-made (synthetic). Natural polymer are found in plant and in animals for example of natural polymers are starch cellulose, protein and rubber.5.Two type of polymerisation in producing synthetic polymer are additionalpolymerisation.6.Double bonds between two carbon atoms usually undergo addition polymerisation.

Uses of synthetic polymers

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# SYNTHETIC POLYMERS IN DAILY LIFE 1.Synthetic polymers have many advantages over other type of materials:a)They are cheap, light-weight and translucent.b)They are easily coloured, easily moulded and shaped.c)They are non-corrosive, waterproof and good insulator.d)They are durable and long lasting because they are resistant to decay, rusting andchemical attacks.2.There are disadvantage using synthetic polymer:a)Most of the synthetic polymer are flammable. When a synthetic polymer materialcatches fire, poisonous fumes are produce causing air pollution.b)Synthetic polymers are non-biodegradable. When there are discharge, they causelitter problem and pollute the environment.c)Plastic container that are left aside in an open area collect rainwater which becomes the breeding ground for mosquitoes.d)There are limitation in recycle have to be separated out as the addition of nonrecyclable polymers in the mixture affect the properties of the recycled polymers.

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E. GLASS AND CERAMICS

GLASS AND CERAMICS

# WHAT ARE GLASS 1.Glass is one of the most useful but inexpensive materials in the world. Many products aremade from glass because of its specials properties.2.Glass is:a) Transparent, hard but brittle.b) A heat and electric insulator.

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c) Resistant to corrosion.d) Chemical not reaction and therefore resistant to chemical attack.e) Easy to maintain.

Types of glass used in our daily lives

# CERAMICS 1. Traditional silicate ceramics are made by heating aluminosilicate clay such as kaolin to a vary high temperature.2. Ceramics have many special properties that make them one of the most useful materials in our everyday life. That:a) Are hard, strong but brittleb) Have high melting point and remain stable at high temperaturec) Are heat and electric instrumentd) Are resistant to corrosion and wear

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e) Are chemically not reactivef) Do not readily deform under stress3. Ceramic play important role in our daily life. They are uses asa) Construction materialsi. Ceramic are strong and hard, uses to make roof tiles, bricks cement, sinks, andtoilet bowls.ii. They are also used to make refractory bricks because high resistant to heat.

b) Decorative itemsi. To make pottery, china plates, and porcelain vases since they do not tarnisheasily and are durable.ii. They are used to make bathroom fixture such as floor and wall tiles.

c) Electrical insulatori. Ceramic are used to make electrical insulator in electrical items such as toasters,fridges and electrical plug.

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F. COMPOSITE MATERIALS

COMPOSITE MATERIALS

# WHAT ARE COMPOSITE MATERIALS 1. A composite materials (or composite) is a structure of materials that is formed by two or more different substances such as metal, glass, ceramic and polymer.2. Some common composite materials are:a) Reinforces concreteb) Superconductorc) Fibre opticd) Fibre glasse) Photochromic glass

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- REINFORCES CONCRETE1. Concrete is hard, fireproof, waterproof, comparatively cheap and easy to maintain. It is more important construction materials.2. The reinforces is a combination of concrete and steel.

- SUPERCONDUCTOR1. Metal such as copper and aluminium are good conductor of electricity, but 20% of the electric energy is lost in the form of heat during transmission.2. Super conductor are materials that have no resistance to the flow of electricity at a particular temperature. Hence, 100% electricity transmission is possible.3. One of the most dramatic properties of a superconductor is its ability to levitate a magnet. Superconductor are used to build magnetically levitate high-speed train (at about 552 km/h).4. Superconductor are used to make chips for smaller and faster supercomputer.Superconductor also play an important role in high speed data processing in internet communication.

- FIBRE OPTIC1. Fibre optic is a composite material that in used to transmit signals for light wave.2. Fibre optic is used ina) Telecommunicate where the telephone substation are liked by fibre optic cables.b) Domestic cable television networkc) Closed circuit television security system.3. Fibre optic also used in medical fields. It is used in a number of instrument which enable the investigation for internal body part without having to perform surgery.

- FIBRE GLASS1. Fibre glass is glass in the form of fine threads. Molten gas is dropped onto a refractory rating disc when the glass flies off the disc glass to form fibre.2. Fibre glass is strong than steel, do not burnt, stretch or rot, resistant to fire and water but is brittle.3. When fibre glass added to a plastic, a new composite material fibre glass reinforces plastic is formed.4. Fibre glass reinforces plastic has more superior properties than glass and plastic. It is :a) Extremely strongb) Light weigh

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c) Resistant to fire and waterd) Can be molded, shaped and twisted

- PHOTOCHROMIC GLASS1. When 0.01 to 0.1% of silver chloride (a type of photochromic substances) and a small amount of copper (II) chloride are added to molten silicon dioxide, photochromic glass is formed.2. The photochromic glass has a special properties. It darken when exposed to strong sunlight or ultraviolet.3. Photochromic glass is suitable for making sunglasses.

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REFERENCES

1. http://www.slideshare.net/faridahhamat/chapter-9-manufacture-substances

2. Tan Yin Toon, Loh Wai Leng, Tan On Tin, Success Chemistry SPM, Oxford Fajar Sdn Bhd.

3. Form 4 Chemistry Text Book.

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4. Jamalia Jamil, Au Wei Leong, Smart Chemistry Form 4,Preston Corporation Sdn Bhd.

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