Folio Chemistry Form 4 Chapter 9

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← 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 materiala.

(H4SO4)

← 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 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 dioxide SO2. S(s)+O2(g)(SO2(g)
sulphur
ii. sulphur dioxide is dried and purified.

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 condition to produce sulphur trioxide SO3. 2SO2(g)+O2(g) 2SO3(g)

ii. The optimum used are
a) Temperature:450-500°C
b) Pressure: 2-3 atmospheres
c) 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 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 directly into water.

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

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, alarge cloud of sulphuric acid fumes is produced, which is corrosive and causes severe air pollution.

In the converter

SULPHUR DIOXIDE AND ENVIRONMENTAL POLLUTION

1. Sulphur dioxide is one of the by-product of contact process. It is a colourless and 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 form sulphurous acidic.

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

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

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

Acid rain and environmental pollution

(NH3)

← 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...
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