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CHEMISTRY(FORM 4)

MANUFACTURED SUBSTANCESIN INDUSTRY(CHAPTER 9)

NAME:MUHAMMAD FARIZZUAN BIN

SAPURI

CLASS:405

1



OBJECTIVES

• Understand the manufacture of sulphuric acid.

• Synthesise the manufacture of ammonia and its salts.

• Understand alloys.

• Evaluate the uses of synthetic polymer.

• Apply the uses of glass and ceramics.

• Evaluate the uses of composite materials.

• Appreciate various synthetic industrial materials.

2



SULPHURIC ACID

(H4SO4)• USES OF SULPHURIC ACID

1. Sulphuric acid is used to produce chemical fertilizer such as ammoniumsulphate and potassium sulphate, which are highly soluble in water and can beeasily 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 SULPHURIC ACID

1. Sulphuric acid is manufactured in industry though contact process

2. The process contain three stage STAGE1: Production Of Sulphur Dioxide From Sulphur

i. Combustion of sulphur or sulphide ores in the air produce sulphur dioxideSO2.

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

ii. sulphur dioxide is dried and purified.

3



STAGE2: Production Of Sulphur Trioxide From Sulphur Dioxide i. The purified sulphur dioxide SO2 and excess air are passed over

vanadium(V) oxide V2O5 at controlled optimum condition optimum conditionto 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 againover the catalyst in the converter.

STAGE3: Conversion of trioxide to sulphuric acid i. 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 directlyinto water.

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

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

pollution.

4



In the converter

SULPHUR DIOXIDE AND

ENVIRONMENTALPOLLUTION

1. Sulphur dioxide is one of the by-product of contact process. It is a colourlessand poisonous 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 formsulphurous acidic.

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

4. Oxidation of sulphur acid by oxygen produce sulphuric acid, H2SO4, which fallsto the earth as acid rain. Sulphur trioxide is also easily oxidised in the air toform sulphur trioxide. Sulphur trioxide dissolve in rainwater to produce sulphuricacid.

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

5

Sulph

Ur

Oxygen

S(s) +

O2(g)SO2(g)

SO2(g) +

H2SO4(aq)H2S2O7(l)H2S2O7(l) +

H2O(l)2H2SO4(aq)

2SO(g) + O2(g) 2SO3(g)Temperature: 450-500°C

Pressure: 2-3 atmospheres

Catalyst: Vanadium(V) oxideOxyge

Unreacted

2%so2 is

flowed back

to converter together with

oxygen

The Contact Process

Outline Of Contact process



Acid rain and environmental pollution

(NH3)6



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.

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 becomealkaline. 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

MANUFACTURE OF AMMONIA IN INDUSTRY

7



1. Ammonia is manufacture on a large scale in industry through the haber process. In this process, ammonia is formed form direct combination of nitrogenand hydrogen gas in the volume ratio 1:3.

2. The gas nitrogen obtain form the fractional distillation of liquefied air. Thehydrogen 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 catalystunder controlled 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 intoammonia gas. The nitrogen and hydrogen that have not reacted are then flowback over the catalyst again in the reactor chamber.

5. The ammonia product is then cooled at a low temperature so that it condensesinto a liquid in the cooling chamber.

8

The Haber Process



AMMONIUM FERTILIZERS

1. Nitrogen is required in large amount by plant to make proteins which arenecessary for growth and cell repair.

2. Most plant are not able to get a nitrogen supply directly from the air althoughit is abundant in the air (78%). Plants can only absorb soluble nitrogencompounds from soil through their roots.

3. The nitrogen compounds are usually soluble nitric salt, ammonia andammonia 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

9

Nitrogen Hydrogen

N2 and H2 are mixed in the proportion of

1:3

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

Temperature: 450-500°C

Pressure: 200-500 atmospheresCatalyst used: Iron fillings

Liquidammonia

In cooling chamber Unreacted N2 and

H2 gases

In the reactor chamber

Outline Of Habert process



ARRANGEMENT OF ATOMS IN MATELS

1. The atom of pure metals are packed together closely. This causes the metal tohave a hight density

2. The forces of attraction between atoms (metallic bonds) are strong. More heatenergy 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 toconduct electricity. Metal are, therefore, good electrical conductors.

5. Since atoms of pure metal are of the same size, they are arranged orderly in aregular layered pattern. When a force is applied to metal, layer of atom slideeasily over one another. This make pure metals soft, malleable and ductile.

10

Force

Layer of atom slide

Metals are ductile

Force

The shape of the

metal change

Matel are malleable

Metals are ductile

Metals are ductile



WHAT ARE ALLOYS

1. Pure metal are usually too soft for most uses. They also have a lowresistance to corrosion. 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 aspecific proportion. 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 strength

i. Pure iron is soft and vary malleable. When a small amount of carbon isadded to iron, an alloy, steal is formed. The more carbon is added, thestronger the steel becomes.

ii. Pure aluminium is light but not strong. With a small amount of copper and magnesium are added to aluminium, a strong, light and durablealloy call duralumin 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. Theseproperties make stainless steel suitable for making surgical instrument

and cutlery.ii. Pure copper tarnish easily. When zinc (30%) is added, the yellow alloy

which is known as brass develops a high resistance to corrosion.c)Enhancing the appearance

i. Pewter, an alloy of tin (97%), antimony and copper is not only hard butalso has a more beautiful white silvery appearance.

ii. When copper is mixed with nickel to form cupronickel, an alloy that hasan attractive silvery, bright appearance is formed which is suitable for making coins.

WHAT ARE ALLOYS

4. Pure metal are usually too soft for most uses. They also have a lowresistance to corrosion. They rush and tarnish easily.5. To improve the physical properties of metal, a small amount of another element (usually metal) is added to form another an alloy.

11



6. An alloy is a mixture of two or more metals (something non-metal) in aspecific proportion. For example:


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 isadded to iron, an alloy, steal is formed. The more carbon is added, thestronger the steel becomes.




and cutlery.ii. Pure copper tarnish easily. When zinc (30%) is added, the yellow alloywhich is known as brass develops a high resistance to corrosion.

c)Enhancing the appearanceiii. Pewter, an alloy of tin (97%), antimony and copper is not only hard but

also has a more beautiful white silvery appearance.iv. When copper is mixed with nickel to form cupronickel, an alloy that has

an attractive silvery, bright appearance is formed which is suitable for making coins.

WHAT ARE ALLOYS

7. Pure metal are usually too soft for most uses. They also have a lowresistance to corrosion. They rush and tarnish easily.8. To improve the physical properties of metal, a small amount of another element (usually metal) is added to form another an alloy.9. An alloy is a mixture of two or more metals (something non-metal) in aspecific proportion. For example:



a)Increase the strengthi. Pure iron is soft and vary malleable. When a small amount of carbon is

added to iron, an alloy, steal is formed. The more carbon is added, thestronger the steel becomes.


b)Improving the resistance to corrosion

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i. 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. Theseproperties make stainless steel suitable for making surgical instrumentand cutlery.

ii. Pure copper tarnish easily. When zinc (30%) is added, the yellow alloy

which is known as brass develops a high resistance to corrosion.c)Enhancing the appearancev. Pewter, an alloy of tin (97%), antimony and copper is not only hard but

also has a more beautiful white silvery appearance.vi. When copper is mixed with nickel to form cupronickel, an alloy that has


WHAT ARE ALLOYS

10.Pure metal are usually too soft for most uses. They also have a lowresistance to corrosion. They rush and tarnish easily.11.To improve the physical properties of metal, a small amount of another element (usually metal) is added to form another an alloy.12.An alloy is a mixture of two or more metals (something non-metal) in aspecific proportion. For example:



i. Pure iron is soft and vary malleable. When a small amount of carbon is




carbon, 18% of chromium and 1% of nickel does not rush. Theseproperties make stainless steel suitable for making surgical instrumentand cutlery.



vii. Pewter, an alloy of tin (97%), antimony and copper is not only hard butalso has a more beautiful white silvery appearance.

viii. When copper is mixed with nickel to form cupronickel, an alloy that hasan attractive silvery, bright appearance is formed which is suitable for making coins.

13



WHAT ARE ALLOYS








ii. Pure copper tarnish easily. When zinc (30%) is added, the yellow alloywhich is known as brass develops a high resistance to corrosion.

c)Enhancing the appearance

ix. Pewter, an alloy of tin (97%), antimony and copper is not only hard butalso has a more beautiful white silvery appearance.

x. When copper is mixed with nickel to form cupronickel, an alloy that hasan attractive silvery, bright appearance is formed which is suitable for making coins.

WHAT ARE ALLOYS

16.Pure metal are usually too soft for most uses. They also have a low

resistance to corrosion. They rush and tarnish easily.17.To improve the physical properties of metal, a small amount of another element (usually metal) is added to form another an alloy.18.An alloy is a mixture of two or more metals (something non-metal) in aspecific proportion. For example:



14





ii. Pure aluminium is light but not strong. With a small amount of copper

and magnesium are added to aluminium, a strong, light and durablealloy call duralumin is produced.b)Improving the resistance to corrosion



c)Enhancing the appearancexi. Pewter, an alloy of tin (97%), antimony and copper is not only hard but

also has a more beautiful white silvery appearance.xii. When copper is mixed with nickel to form cupronickel, an alloy that hasan attractive silvery, bright appearance is formed which is suitable for making coins.

WHAT ARE ALLOYS

19.Pure metal are usually too soft for most uses. They also have a lowresistance to corrosion. They rush and tarnish easily.20.To improve the physical properties of metal, a small amount of another

element (usually metal) is added to form another an alloy.21.An alloy is a mixture of two or more metals (something non-metal) in aspecific proportion. For example:





and magnesium are added to aluminium, a strong, light and durablealloy call duralumin is produced.



15




c)Enhancing the appearancexiii. Pewter, an alloy of tin (97%), antimony and copper is not only hard but

also has a more beautiful white silvery appearance.

xiv. When copper is mixed with nickel to form cupronickel, an alloy that hasan attractive silvery, bright appearance is formed which is suitable for making coins.

WHAT ARE ALLOYS





ii. Pure aluminium is light but not strong. With a small amount of copper and magnesium are added to aluminium, a strong, light and durable

alloy call duralumin is produced.b)Improving the resistance to corrosion



c)Enhancing the appearancexv. Pewter, an alloy of tin (97%), antimony and copper is not only hard but


xvi. When copper is mixed with nickel to form cupronickel, an alloy that hasan attractive silvery, bright appearance is formed which is suitable for making coins.

WHAT ARE ALLOYS

16



25.Pure metal are usually too soft for most uses. They also have a lowresistance to corrosion. They rush and tarnish easily.26.To improve the physical properties of metal, a small amount of another element (usually metal) is added to form another an alloy.27.An alloy is a mixture of two or more metals (something non-metal) in a

specific proportion. For example:a. Bronze (90% of copper and 10% of tin)b. Steel (99% of iron and 1% of carbon)




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. Theseproperties make stainless steel suitable for making surgical instrumentand cutlery.


c)Enhancing the appearancexvii. Pewter, an alloy of tin (97%), antimony and copper is not only hard but

also has a more beautiful white silvery appearance.xviii. When copper is mixed with nickel to form cupronickel, an alloy that has


WHAT ARE ALLOYS





17







c)Enhancing the appearancexix. Pewter, an alloy of tin (97%), antimony and copper is not only hard but

also has a more beautiful white silvery appearance.xx. When copper is mixed with nickel to form cupronickel, an alloy that has


WHAT ARE ALLOYS


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:







c)Enhancing the appearancexxi. Pewter, an alloy of tin (97%), antimony and copper is not only hard but


18



xxii. When copper is mixed with nickel to form cupronickel, an alloy that hasan attractive silvery, bright appearance is formed which is suitable for making coins.

WHAT ARE ALLOYS









which is known as brass develops a high resistance to corrosion.c)Enhancing the appearancexxiii. Pewter, an alloy of tin (97%), antimony and copper is not only hard but

also has a more beautiful white silvery appearance.xxiv. When copper is mixed with nickel to form cupronickel, an alloy that has


WHAT ARE ALLOYS

37.Pure metal are usually too soft for most uses. They also have a lowresistance to corrosion. They rush and tarnish easily.38.To improve the physical properties of metal, a small amount of another element (usually metal) is added to form another an alloy.

19



39.An alloy is a mixture of two or more metals (something non-metal) in aspecific proportion. For example:








c)Enhancing the appearancexxv. Pewter, an alloy of tin (97%), antimony and copper is not only hard but

also has a more beautiful white silvery appearance.xxvi. When copper is mixed with nickel to form cupronickel, an alloy that has


WHAT ARE ALLOYS








20





which is known as brass develops a high resistance to corrosion.c)Enhancing the appearancexxvii. Pewter, an alloy of tin (97%), antimony and copper is not only hard but

also has a more beautiful white silvery appearance.xxviii. When copper is mixed with nickel to form cupronickel, an alloy that has


WHAT ARE ALLOYS










which is known as brass develops a high resistance to corrosion.c)Enhancing the appearancexxix. Pewter, an alloy of tin (97%), antimony and copper is not only hard but

also has a more beautiful white silvery appearance.xxx. When copper is mixed with nickel to form cupronickel, an alloy that has


21



WHAT ARE ALLOYS










xxxi. Pewter, an alloy of tin (97%), antimony and copper is not only hard butalso has a more beautiful white silvery appearance.

xxxii. When copper is mixed with nickel to form cupronickel, an alloy that hasan attractive silvery, bright appearance is formed which is suitable for making coins.

WHAT ARE ALLOYS





22









c)Enhancing the appearancexxxiii. Pewter, an alloy of tin (97%), antimony and copper is not only hard but

also has a more beautiful white silvery appearance.xxxiv. When copper is mixed with nickel to form cupronickel, an alloy that hasan attractive silvery, bright appearance is formed which is suitable for making coins.

WHAT ARE ALLOYS










23




c)Enhancing the appearancexxxv. Pewter, an alloy of tin (97%), antimony and copper is not only hard but


xxxvi. When copper is mixed with nickel to form cupronickel, an alloy that hasan attractive silvery, bright appearance is formed which is suitable for making coins.

WHAT ARE ALLOYS









c)Enhancing the appearancexxxvii. Pewter, an alloy of tin (97%), antimony and copper is not only hard but


xxxviii. When copper is mixed with nickel to form cupronickel, an alloy that hasan attractive silvery, bright appearance is formed which is suitable for making coins.

WHAT ARE ALLOYS

24








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. Theseproperties make stainless steel suitable for making surgical instrumentand cutlery.


c)Enhancing the appearancexxxix. Pewter, an alloy of tin (97%), antimony and copper is not only hard but

also has a more beautiful white silvery appearance.xl. When copper is mixed with nickel to form cupronickel, an alloy that has


WHAT ARE ALLOYS





25







c)Enhancing the appearancexli. Pewter, an alloy of tin (97%), antimony and copper is not only hard but

also has a more beautiful white silvery appearance.xlii. When copper is mixed with nickel to form cupronickel, an alloy that has


WHAT ARE ALLOYS


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:







c)Enhancing the appearancexliii. Pewter, an alloy of tin (97%), antimony and copper is not only hard but


26



xliv. When copper is mixed with nickel to form cupronickel, an alloy that hasan attractive silvery, bright appearance is formed which is suitable for making coins.

WHAT ARE ALLOYS










xlv. Pewter, an alloy of tin (97%), antimony and copper is not only hard butalso has a more beautiful white silvery appearance.

xlvi. When copper is mixed with nickel to form cupronickel, an alloy that hasan attractive silvery, bright appearance is formed which is suitable for making coins.

WHAT ARE ALLOYS

70.Pure metal are usually too soft for most uses. They also have a lowresistance to corrosion. They rush and tarnish easily.71.To improve the physical properties of metal, a small amount of another element (usually metal) is added to form another an alloy.

27



72.An alloy is a mixture of two or more metals (something non-metal) in aspecific proportion. For example:








c)Enhancing the appearancexlvii. Pewter, an alloy of tin (97%), antimony and copper is not only hard but

also has a more beautiful white silvery appearance.xlviii. When copper is mixed with nickel to form cupronickel, an alloy that has


WHAT ARE ALLOYS








28





which is known as brass develops a high resistance to corrosion.c)Enhancing the appearancexlix. Pewter, an alloy of tin (97%), antimony and copper is not only hard but

also has a more beautiful white silvery appearance.l. When copper is mixed with nickel to form cupronickel, an alloy that has


WHAT ARE ALLOYS











li. Pewter, an alloy of tin (97%), antimony and copper is not only hard butalso has a more beautiful white silvery appearance.

lii. When copper is mixed with nickel to form cupronickel, an alloy that hasan attractive silvery, bright appearance is formed which is suitable for making coins.

29



WHAT ARE ALLOYS










liii. Pewter, an alloy of tin (97%), antimony and copper is not only hard butalso has a more beautiful white silvery appearance.

liv. When copper is mixed with nickel to form cupronickel, an alloy that hasan attractive silvery, bright appearance is formed which is suitable for making coins.

WHAT ARE ALLOYS





30









c)Enhancing the appearancelv. Pewter, an alloy of tin (97%), antimony and copper is not only hard but

also has a more beautiful white silvery appearance.lvi. When copper is mixed with nickel to form cupronickel, an alloy that hasan attractive silvery, bright appearance is formed which is suitable for making coins.

WHAT ARE ALLOYS










31




c)Enhancing the appearancelvii. Pewter, an alloy of tin (97%), antimony and copper is not only hard but


lviii. When copper is mixed with nickel to form cupronickel, an alloy that hasan attractive silvery, bright appearance is formed which is suitable for making coins.

WHAT ARE ALLOYS









c)Enhancing the appearancelix. Pewter, an alloy of tin (97%), antimony and copper is not only hard but


lx. When copper is mixed with nickel to form cupronickel, an alloy that hasan attractive silvery, bright appearance is formed which is suitable for making coins.

WHAT ARE ALLOYS

32







c)Enhancing the appearancelxiii. Pewter, an alloy of tin (97%), antimony and copper is not only hard but

also has a more beautiful white silvery appearance.lxiv. When copper is mixed with nickel to form cupronickel, an alloy that has


34



Alloy Composition Properties Uses

High carbon steel 99% iron1% carbon

Strong,hard andhigh wear

resistance

• Making of cuttingtools, hammers

and chiselsStainless steel 80.6% iron

0.4% carbon18%chromium

1% nickel

Do not rust andtarnish, strong and

durable

• Making of surgicalinstrument,knives forks andspoons

Brass 70% copper 30% zinc

Hard, do not rust,bright appearance

• Making of ornaments,electrical wiringand plug.

Bronze 90% copper

10% tin

Hard, do not

corrode easily anddurable

• For casting bells,

medals, swordsand statues

Pewter 90% tin2.5% copper

0.5% antimony

Ductile andmalleable, white

silvery appearance

• Making of ornaments,souvenirs andmugs

Duralumin 95% aluminium4% copper

1%magnesium

Light, strong anddurable

• Making part of aircrafts andracing cars

Cupronickel 75%copper 25%nickel

Attractive, silveryappearance, hard

and tough

• Making of silver coins

Composition, properties and uses of alloys

35



The formationof alloy

WHAT ARE POLYMER

1. Molecule that consist of a large number of small identical or similar units joinedtogether 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 longchain polymer is called polymerisation.

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 starchcellulose, protein and rubber.

5. Two type of polymerisation in producing synthetic polymer are additionalpolymerisation.

6. Double bonds between two carbon atoms usually undergo additionpolymerisation.

Some Common Addition Polymers

Name(s) Formula Monomer Properties Uses

Polyethylenelow density

(LDPE)

–(CH2-CH2)n –

ethyleneCH2=CH2

soft, waxy solidfilm wrap,plastic bags

Polyethylenehigh density(HDPE)

–(CH2-CH2)n –

ethyleneCH2=CH2

rigid, translucentsolid

electricalinsulationbottles, toys

Polypropylene(PP) differentgrades

–[CH2-CH(CH3)]n –

propyleneCH2=CHCH3

atactic: soft,elastic solidisotactic: hard,strong solid

similar to LDPEcarpet,upholstery

Poly(vinyl

chloride)(PVC)

–(CH2-

CHCl)n –

vinyl chloride

CH2=CHCl strong rigid solid

pipes, siding,

flooring

Poly(vinylidenechloride)(Saran A)

–(CH2-CCl2)n –

vinylidenechlorideCH2=CCl2

dense, high-melting solid

seat covers,films

Polystyrene(PS)

–[CH2-CH(C6H5)]n –

styreneCH2=CHC6H5

hard, rigid, clear solid

toys, cabinetspackaging

36



soluble in organicsolvents

(foamed)

Polyacrylonitrile(PAN, Orlon,

Acrilan)

–(CH2-CHCN)n –

acrylonitrileCH2=CHCN

high-melting solidsoluble in organic

solvents

rugs, blanketsclothing

Polytetrafluoroethylene(PTFE, Teflon)

–(CF2-CF2)n –

tetrafluoroethyleneCF2=CF2

resistant, smoothsolid

non-sticksurfaceselectricalinsulation

Poly(methylmethacrylate)(PMMA, Lucite,Plexiglas)

–[CH2-C(CH3)CO2

CH3]n –

methylmethacrylateCH2=C(CH3)CO2CH3

hard, transparentsolid

lighting covers,signsskylights

Poly(vinylacetate)(PVAc)

–(CH2-CHOCOCH3

)n –

vinyl acetateCH2=CHOCOCH3

soft, sticky solid latex paints,adhesives

cis-Polyisoprenenatural rubber

–[CH2-CH=C(CH3)-CH2]n –

isopreneCH2=CH-C(CH3)=CH2

soft, sticky solidrequiresvulcanizationfor practical use

Polychloroprene(cis + trans)(Neoprene)

–[CH2-CH=CCl-CH2]n –

chloropreneCH2=CH-CCl=CH2

tough, rubberysolid

synthetic rubber oil resistant

Uses of synthetic polymers

37



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 and chemical attacks.2. There are disadvantage using synthetic polymer:

a. Most of the synthetic polymer are flammable. When a synthetic polymer material catches fire, poisonous fumes are produce causing air pollution.

b. Synthetic polymers are non-biodegradable. When there are discharge,they cause litter 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 non-recyclable polymers in the mixture affect the properties of therecycled polymers.

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WHAT ARE GLASS

1. Glass is one of the most useful but inexpensive materials in the world. Manyproducts are made from glass because of its specials properties.

2. Glass is:a. Transparent, hard but brittle.b. A heat and electric insulator.c. Resistant to corrosion.d. Chemical not reaction and therefore resistant to chemical attack.e. Easy to maintain.

Type of glass Composition Properties Uses

Fused glass SiO2: 100% • Transparent

• High meltingpoint

• Good heatinsulator

• Lens

• Telescope mirrors

• Laboratoryapparatus

Soda-lime glass SiO2: 75%Na2O:15%

CaO: 9%Other:1%

• Low meltingpoint, easily

molded intodesired shapeand size

• Low resistant tochemical attacks

• Brittle

• Drinking glass,bottles

•Electric bulbs

• Window glass

Borosilicate glass SiO2: 78%B2O3: 12%Na2O: 5%CaO: 3%Al2O3:2%

• Resistantchemical attackand durable

• High meltingpoint

• Good insulator toheat

• Cooking utensils

• Laboratoryglassware suchas conical flaksand boiling tube

Lead crystal glass(flint glass)

SiO2: 70%Pbo/PbO2:20%

Na2O: 10%

• High refractiveindex

• High density

• Attractiveglitteringappearance

• Lenses andprisms

• Decorativeglassware and artobject

• Imation jewellery

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CERAMICS

1. Traditional silicate ceramics are made by heating aluminosilicate clay such askaolin to a vary high temperature.

2. Ceramics have many special properties that make them one of the most usefulmaterials 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 e.Are chemically not reactivef. Do not readily deform under stress

3. Ceramic play important role in our daily life. They are uses asa.Construction materials

i. Ceramic are strong and hard, uses to make roof tiles, bricks cement,sinks, and toilet bowls.

ii. They are also used to make refractory bricks because high resistant toheat.

b.Decorative itemsi. To make pottery, china plates, and porcelain vases since they do not

tarnish easily and are durable.ii. They are used to make bathroom fixture such as floor and wall tiles.

c.Electrical insulator

i. Ceramic are used to make electrical insulator in electrical items such astoasters, fridges and electrical plug.

Materials Melting point/°C

Density/G cm-3 Elasticmodulus/ GPa

Hardness/mohs

OxideceramicAlumina,AL2O3

Beryllia, BeOZirconia, ZiO

205425742710

3.973.015.68

380370210

988

Non-oxideceramicsBoroncarbide,B4C3

Silicon nitride,Si3, n4

23502830

1900

2.503.16

3.17

280400

310

99

9

MetalsAluminium 660 2.70 70 3

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Steel 1515 7.86 205 5

WHAT ARE COMPOSITE MATERIALS

1. A composite materials (or composite) is a structure of materials that is formedby two or more different substances such as metal, glass, ceramic andpolymer.

2. Some common composite materials are:a.Reinforces concreteb.Superconductor c.Fibre opticd.Fibre glasse.Photochromic glass

REINFORCES CONCRETE

1. Concrete is hard, fireproof, waterproof, comparatively cheap and easy tomaintain. It is more important construction materials.

2. The reinforces is a combination of concrete and steel.

SUPERCONDUCTOR

1. 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 electricityat a particular temperature. Hence, 100% electricity transmission is possible.

3. One of the most dramatic properties of a superconductor is its ability to levitatea magnet. Superconductor are used to build magnetically levitate high-speedtrain (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 ininternet communication.

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FIBRE OPTIC

1. Fibre optic is a composite material that in used to transmit signals for lightwave.

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 instrumentwhich enable the investigation for internal body part without having to performsurgery.

FIBRE GLASS

1. Fibre glass is glass in the form of fine threads. Molten gas is dropped onto arefractory 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 andwater but is brittle.

3. When fibre glass added to a plastic, a new composite material fibre glassreinforces plastic is formed.

4. Fibre glass reinforces plastic has more superior properties than glass andplastic. It is

a. Extremely strongb. Light weighc. Resistant to fire and water d. Can be molded, shaped and twisted

PHOTOCHROMIC GLASS

1. When 0.01 to 0.1% of silver chloride (a type of photochromic substances) and asmall 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 tostrong sunlight or ultraviolet.

3. Photochromic glass is suitable for making sunglasses.

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