9.1 Manufacture of Sulphuric Acid

Sulphuric acid
■ Sulphuric acid

	►	A non-volatile diprotic mineral acid with the molecular formula H2SO4
	►	A pungent, colorless viscous liquid which is soluble in water at all concentrations.
	►	One of the most important chemical industries.

■ This video contains information on the uses of sulphuric acid

Uses of sulphuric acid
■ Uses of sulphuric acid

Fertiliser	Detergents	Synthetic fibre
Paint pigments	Electrolyte

Manufacture of sulphuric acid in industry
■ Sulphuric acid

	►	Sulphuric acid
	►	Raw materials used to manufacture the sulphuric acid are sulphur, air and water.

■ This video contains information on the syntheis of sulphuric acid through the Contact process in industry.

■ Contact Process

	►	Stage I: Production of sulphur dioxide gas, SO2 ○ Sulphur dioxide gas, SO2, is produced by burning sulphur in air. S(s) + O2(g) → SO2(g)
	►	Stage II: Conversion of sulphur sulphide to sulphur trioxide, SO3 ○ Pure and dry sulphur dioxide with excess oxygen are passed through a converter. ○ The gas mixture is passed over vanadium(V) oxide, V2O5 (catalyst) at temperature 450°C – 500°C and under the pressure of 1 atmosphere. ○ A high percentage of the sulphur dioxide is converted into sulphur trioxide. 2SO2(g) + O2(g) ⇌ 2SO3(g)
	►	Stage III: Production of sulphuric acid, H2SO4 ○ The sulphur trioxide produced is dissolved in concentrated sulphuric acid to produce oleum, H2S2O7, a viscous liquid. SO3(g) + H2SO4(l) → H2S2O7(l) ○ Oleum is then diluted with an equal volume of water to produce concentrated sulphuric acid (98%). H2S2O7(l) + H2O(l) → 2H2SO4(l)
	►	The animation below shows the industrial process in the manufacture of sulphuric acid.

■ This video contains information on the manufacture of sulphuric acid in industry.

Environmental pollution by sulphur dioxide
■ Sources of sulphur dioxide:

	►	Volcanoes eruptions.
	►	Waste gases from various industrial process.
	►	Burning of fossil flues such as petroleum and coal.

■ Effects of sulphur dioxide in air:

	►	Sulphur dioxide is a poisonous and acidic gas.
	►	It can diffuse into our respiratory system and cause diseases such as bronchitis, asthma and lung infections.

■ Acid rain:

	►	Sulphur dioxide gas dissolves in atmospheric water to produce a mixture of sulphurous acid, H2SO3 and sulphuric acid, H2SO4. ○ SO2 + H2O → H2SO3 ○ 2SO2 + O2 + 2H2O → 2H2SO4
	►	Both acids presence in rainwater results in acid rain.
	►	The animation below shows the formation of acid rain.

■ Effects of acid rain:

	►	Increase the metal corrosion speed.
	►	Results in highly acidic soil which is not conducive for agriculture activities.
	►	Cause the destruction of concrete buildings.
	►	Lower the pH value of water in river and seas.
	►	Destroy the nutrients in the soil.

↶ SPM Chemistry

9.2 Manufacture of Ammonia and its Salt →

⇲ For exercise(objective and subjective), download for free on Android OS.