Name : Fatin Nadzirah Binti Yusof

No Maktab : 11435

Kelas : 4B (2011)

Guru MP : Miss Zurina

9.1 Sulphuric Acid

Uses of sulphuric acid

1. Sulphuric acid is used to manufacture almost all products. Some of the example are : Fertilisers Paint pigment Detergents Synthetic fibres Electrolyte in car batteries Cleaning metals Plastics Other chemicals

2. Sulphuric acid is also used in laboratory in school as follows: As drying agent As dehydrating agent As catalyst As strong acid

Manufacture of sulphuric acid in industry

CONTACT PROCESS

Stage 1: Combustion of Sulphur In the furnace, molten sulphur is burnt in dry air to produce sulphur dioxide, SO2. The

gas produced is purified and cooled.S(l) + O2(g) SO2(g)

Stage 2: Conversion of sulphur dioxide to sulphur trioxide in the converter In the converter, sulphur dioxide, SO2 and excess oxygen gas, O2 are passed over a

few plates of vanadium (V) oxide, V2O5 catalyst at 4500C to produce sulphur trioxide, SO3.2SO2(g) + O2(g) 2SO3(g)

About 99.5% of the sulphur dioxide, SO2 is converted into sulphur trioxide, SO3 through this reversible reaction.

Stage 3: Production of sulphuric acid in absorber and diluter In the absorber, the sulphur trioxide, SO3 is first reacted with concentrated sulphuric

acid, H2SO4 to form a product called oleum, H2S2O7.SO3(g) + H2SO4(l) H2S2O7

The oleum, H2S2O7 is then diluted with water to produced concentrated sulphuric acid, H2SO4 in large quantities.H2S2O7(l) + H2O(l) 2H2SO4(l)

The two reactions in the third stage are equivalent to adding sulphur trioxide, SO3 directly to water.SO3(g) + H2O(l) H2SO4(l)

Environmental pollution by sulphuric acid

1. Sulphur dioxide is an acidic and poisoinous gas that pollutes the environment.

2. The sources of sulphur dioxide :

3. Sulphuric acid is formed by atmospheric oxidation of sulphur dioxide in the

presence of water. It also produces sulphurous acid.

4. Sulphuric acid and sulphurous acid are constituents of acid rain.

5. Acid rain can cause many effects such as :

i. Corrodes concrete buildings and metal structure

ii. Destroys trees and plants

iii. Decrease the pH of th soil and make it become acidic

iv. Acid rain flows into the rivers and increases the acidity of water and kill

aquatic living things.

6. Hence, we must reduce the sulphur dioxide from the atmosphere by:

i. Use low sulphur fuels to reduce the emission of sulphur dioxide in exhaust

gases

ii. Remove sulphur dioxide from waste air by treating it with calcium

carbonated before it is released

iii. Neutralise the acidic soil and water by treating them with calcium oxide,

calcium hydroxide and calcium carbonate.

9.2 Ammonia and Its Salts

Uses of ammonia

1. Ammonia is produced industrially as an intermediate compound and as raw material

for many other chemical processes.

2. The main uses of ammonia are as follows :

To manufactured nitrogenous fertilisers needed for plant growth

As raw material for the manufactured of nitric acid

As cooling agent in refrigerators

To produce ammonium chloride used as electrolyte in dry cells

To prevent coagulation of latex

To make synthetic fibres such as nylon

As smelling salts to revive people who have fainted

Making of explosives

Properties of ammonia

1. Ammonia is a covalent compound with the following physical properties :

Manufacture of ammonia in industry

HABER PROCESS

1. Gases mixed and scrubbed Haber process combines N2 gas from the air with H2 gas from natural gas to form

NH3. The two gases are mixed. The mixture is scrubbed to get rid of impurities.2. Compressor

One volume of N2 gas and three volume of H2 gas is compressed to a pressure of 200 – 500 atm

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

Then, it goes to the converter. It is then passed through layers of iron catalyst with aluminium oxide as a promoter at a temperature of 4500C – 5000C

4. Cooler A mixture of three gases leaves the converter. It is cooled until the ammonia

condenses. The nitrogen and hydrogen are pumped back to the converter for another chance to react.

5. Storage tanks NH3 is formed and then liquefy and separated to get a better yield. The NH3 is run

into tanks and stored as a liquid under pressure.

Ammonium Fertilisers

1. Nitrogen is used by plant to make protein. Protein is important for the growth of

plants. Other nutrients needed by plants include phosphorus, potassium, calcium and

magnesium.

2. Nitrogenous compounds are removed from the soil by the plants. Some are replaced

naturally by bacteria. To restore the balance, nitrogenous fertilisers are added to the

soil.

3. Nitrogenous fertilisers contain ammonium ions.

4. In the soil, the ammonium ions are converted to nitrate ions by the bacteria. This is

because nitrogen can only be absorbed by plants in the form of soluble nitrate ions.

5. Examples of ammonium fertilisers are :

Ammonium nitrate

Ammonium sulphate

Ammonium phosphate

Urea

6. The effectiveness of ammonium fertilisers is determined by the percentage of nitrogen

by mass in them.

7. The fertilisers with a higher percentage of nitrogen is more effective for growth than

those fertilisers with a low percentage of nitrogen.

8. The percentage of nitrogen by mass can be calculated from the formulae of the

fertilisers using the following formula.

9.3 Alloys

Pure Metal

Typical pure metals have the following physical properties :

Ductile

Malleable

Lustrous

High density

High melting and boiling points

Good conductors of heat and electricity

2. Pure metals are weak and soft because the arrangement of atoms in pure metals make

them ductile and malleable.

3. A pure metal contains atoms of the same size arranged in a regular and organized

closed-packed structure.

4. Pure metals are soft because the orderly arrangement of atoms enables

the layers of atoms to slide over each other easily when an external force

is applied on them. This makes the metals ductile and can be

drawn to form long wires.

5. There are imperfections in the natural arrangements of metal atoms.

Empty space exist in the structures of pure metals. When hammered or

pressed, groups of metal atoms may slide into new positions in the

empty spaces. This makes metals malleable, able to be made into

different shapes or pressed into thin sheets.

6. The strong forces of attraction between metal atoms requires high energy to overcome

it. Hence, most metals have high melting points.

7. The close-packed arrangement of metal atoms results in the high density of metals.

Alloys

1. An alloy is a mixture of two or more elements with a certain composition in which the

major component is a metal.

2. In the process of alloying, one or more foreign elements are added to a molten metal.

When the alloy hardens, the positions of some of the metal atoms are replaced by the

atom of foreign elements, which size may be bigger or smaller than the original metal

atoms.

3. In an alloy, these atoms of foreign elements disrupt the orderly

arrangement of the metal atoms and also fill up any empty space in the

metal crystal structure.

4. Hence, the layers of metal atoms are prevented from sliding over each

other easily. This makes the alloy harder and stronger, less ductile and less

malleable than its pure metals.

5. The properties of a pure metal are thus improved by making them into alloys.

6. There are three aims of alloying a pure metal:

a) To increase the hardness and strength of a metal

b) To prevent corrosion or rusting

c) To improve the appearance of the metal surface

The Composition, Properties and Uses of Some Alloys

Alloy Composition Properties Uses

Bronze80% copper

20% tin

Hard, strong, does not

corrode easily, shiny

surface

Medals, statues, monuments,

arts,materials

Brass70% copper

30% zincHarder than copper

Musical instrument,

kitchenware, door knobs,

bullets cases, decorative

ornaments, electric parts

Cupro-nickel75% copper

25% nickel

Beautiful surface,

shiny, hard, does not

corrode easily

Coin

Steel99% iron

1% carbonHard, strong

Buildings, bridges, body of

cars, railway track

Stainless steel

74% iron

8% carbon

18% chromium

Shiny, strong, does

not rust

Cutlery, sinks, pipes, surgical

instruments

Duralumin

93% aluminium

3% copper

3% magnesium

1% manganese

Light, strongBody of air crafts, bullet trains,

racing bicycles

Pewter

96% tin

3% copper

1% antimony

Shiny, strong, does

not corrodeArt objects, souvenirs

Solder50% tin

50% lead

Hard, shiny, low

melting point

Soldier for electric wires and

metal

9-carat gold

37.5% gold

51.5% copper

11% silver

Shiny, strong, does

not corrodeJewellery

9.4 Synthetic Polymers

Polymers

1. Polymers can be defined as large molecules composed of numerous smaller, repeating

units known as monomers which are joined by covalent bonds.

2. Polymerisation is the chemical process by which the monomers are joined together to

form the big molecule known as the polymers.

3. There are two types of polymerization process:

a) Addition polymerization

Involves monomers with the carbon-carbon double bonds between the carbon

atoms smaller and simple molecules such as water.

b) Condensation polymerization

Involves the joining up of monomers with the formation of other

4. A polymer is a very big molecule (macromolecule). Hence, the relative molecular

mass of a polymer is large.

5. The properties of polymer are different from its monomers.

6. Polymers can be divided into two types:

Naturally occurring polymers

This type of polymer exists in living things in nature like the plants and

animals.

Examples of naturally occurring polymers are:

Protein

Carbohydrate

Natural rubber

Naturally occurring polymers are formed by the joining of monomers by

polymerization.

Synthetic polymers

These types of polymer are man-made by chemical process in the laboratories.

The raw materials for synthetic polymers are obtained from petroleum.

The types of synthetic polymers include:

Plastics

Fibres

Nylon

Plastic

1. Plastics are made from the products of cracking of petroleum fractions such as

alkenes molecules through addition polymerisation.

2. Plastics are the largest group of synthetic polymers with the following properties :

Can be easily moulded and coloured

Low density

Strong

Inert to chemicals

Insulators of heat and electricity

Impermeable

Non-biodegradable

Monomers, Properties and Uses of Some Commonly Plastic

Name of polymer Monomers Properties Uses

Polythene Ethane

Durable, light,

impermeable, inert to

chemistry, easily melt,

insulator

Shopping bags, plastic

cups and plate, toys

Polypropene Propene

Durable, light,

impermeable, inert to

chemistry, easily melted,

insulator, can be moulded

and coloured

Bottles, furniture, battery

casing, pipes, toys

Polystyrene PhenyletheneHeat insulator, light, can

be moulded, impermeable

Disposable cups and

plates, packaging

materials, toys, heat

insulator

PerspexMethyl

methacrylateTransparent, strong, light

Replacement for glass.

Lenses, optical fibres

Teflon Tetrafluoroethene

Durable, non-stick,

chemically inert, strong,

impermeable

Coating for non-stick

pans, electrical insulators

Advantages of synthetic polymers

Strong and light

Cheap

Able to resist corrosion

Inert to chemical reactions

Easily moulded or shaped and be coloured

Can be made to have special properties

Environmental pollution caused by synthetic polymers

As most of polymers are non-biodegradable, they will not decay like other organic

garbage.

Burning of polymers release harmful and poisonous gases.

Methods to overcome the environmental pollution caused by synthetic

polymers

Reduce, reuse and recycle synthetic polymers

Develop biodegradable polymers

9.5 Glass and Ceramics

1. The main component of both glass and ceramic is silica or silicon dioxide, SiO2.

2. Both glass and ceramic have the same properties as follow :

Hard and brittle

Inert to chemical reactions

Insulators or poor conductors of heat and electricity

Withstand compression but not stretching

Can be easily cleaned

Low cost of production

3. Differences between glass and cerement are, glass is transparent, while ceramic is

opaque. Ceramic can withstand a higher temperature than normal glass.

4. Types of glass are :

a) Fused glass

It is consist mainly of silica or silicon dioxide

It has high heat resistance

b) Soda lime glass

It cannot withstand high temperatures

c) Borosilicate glass

It can withstand high temperature

d) Lead glass

High refractive index

5. Uses of improved glass for specific purpose

a) Photochromic glass

It is sensitive to light intensity

b) Conducting glass

It conducts electricity

6. Ceramic is a manufactured substances made from clay, with the main constituent of

aluminosilicate with small quantity of sand and feldspar.

7. Superconductor is one improved ceramics for specific purposes.

Glass

1. Glass is made up from sand.

2. The major component of glass is SiO2.

3. There are four types of glass which are as follows :

Fused glass

Soda-lime glass

Borosilicate glass

Lead crystal glass

Composition, Properties and Uses of Different Types of Glass

Name of glass Properties Composition Uses

Fused glass

High melting

point

High

temperature

High chemical

durability

Resistant to

thermal shock

Transparent to

ultraviolet and

infrared light

Silicon dioxide

Laboratory

glassware

Arc tubes in lamps

Lenses

Telescope mirrors

Optical fibres

Soda-lime glass Low melting

point

High thermal

expansion

coefficient

Does not

withstand heat

Cracks easily

with sudden

change in

temperature

Silicon dioxide

Sodium oxide

Calcium oxide

Containers such as

bottles, jars and

tumblers

Flat glass

Windowpanes

Mirrors

Light bulbs

Industrial and art

objects

Good chemical

durability

Easy to mould

and shape

Transparent to

visible light

Borosilicate glass

Transparent to

visible light

Resistant to

chemicals

Lower thermal

expansion

coefficient

Resistant to

thermal shock

Can withstand

wide range of

temperature

changes

Silicon dioxide

Boron oxide

Sodium oxide

Calcium oxide

Cookware

Laboratory

glassware

Automobile

headlights

Glass pipelines

Electrical tubes

Lead crystal glass

Soft and easy to

melt

Transparent to

visible light

High density

High refractive

index

Silicon dioxide

Lead(11) oxide

Sodium oxide

Tableware

Art objects

Crystal

Prism

Lenses

Ceramics

1. Ceramics are made from clay and composed of aluminium silicate mixed with sand.

2. The white clay used to ceramics is kaolin which is in rich in kaolinite or hydrated

aluminosilicate.

3. Red clay consists of iron(III) oxide which gives the red colour.

4. Brick, tiles, mugs and clay pots are some examples of traditional ceramics

5. During the making of ceramics, the shaped objects are heated to very high

temperature. They undergo a series of chemical reactions and are hardened to form

ceramics.

6. These chemical reactions are irreversible and the ceramics cannot be melted and

moulded.

How Ceramic are Made

1. Wet clay can be shaped easily because the tiny crystals in it can slide over each other.

Clay has a plastic property. When the clay dries up, it keeps its shape as the crystals

are now stuck together.

2. When heated to above 15000C, a series of chemical reaction produce other chemicals

and glass which packs the tiny mineral crystals together.

3. The object is now glazed and heated again. The reactions in the glaze cause the

surface to be waterproof.

Properties of Ceramics

Very strong and hard

Brittle

Chemically inert and does not corrode

Good insulator of electricity and heat

Very high melting point and heat resistance

Porous but can be made impervious by glazing

Uses of Ceramics

Property Uses Examples

Hard and strong Building materialsTiles, bricks, roofs, cement,

abrasive for grinding

Attractive, easily moulded

and glazed

Decorative pieces and

household items

Vases, porcelain ware, sinks,

bathtubs

Chemically inert and non-

corrosiveKitchenware Cooking pots, plates, bowls

Very high melting point and

good insulator of heatInsulation

Lining of furnace, engine

parts

Electrical insulatorsInsulating parts in electrical

appliances

Spark plugs, insulators in

ovens and electric cables

Inert and non-compressible Medical and dental apparatus Artificial teeth and bones

9.6 Composite Materials

1. Composite material is a structure material that is formed by combining two or more

different substances like metals, alloys, glass, ceramics and polymers. Usually, the

new composite materials formed have properties that are superior to those of the

original components.

2. The composite materials produced are harder, stronger, lighter, more resistant to heat

and corrosion and also for specific purposes.

3. When composite material is formed, the weakness of the components will not exist

anymore.

Comparison of the Properties between Composite Materials with Those of Their Original

Components

Composite

materials

Original

components

Properties

Original Composite

Reinforced

concrete

Concrete

Hard, low tensile strength,

does not rush, high

compression strength,

brittle, fireproof,

waterproof, easy to

maintain and cheap

High tensile strength,

tough, does not crack

easily, relatively cheap,

can be moulded easily,

very low building cost

and needs very little

maintenance SteelGood tensile strength, rust,

expensive

Superconductor

Yitrium oxide,

barium carbonate,

copper(III) oxide

Non-conductor with high

resistance to electricity

Very good conductor

with very little

resistance

Fibre optic

GlassHigher refractive index,

non-conductor

Transparent, cheaper in

materials cost, much

thinner, easily bend and

lighter, less susceptible

to interference, much

greater bandwidth, carry

more data, chemically

more stable than metal

wires and data is

transmitted digitally

PlasticLower refractive index,

non-conductor

FibreglassPlastic Soft, flexible, low density

Hard, strong, densityGlass Brittle, strong, hard

Photochromic

glass

GlassTransparent, not sensitive to

lightTransparent and

sensitive to intensity of

lightSilver chloride,

Silver bromide

Sensitive to intensity of

light