It is manufactured by the contact process.

2SO2 (g)+O2 (g)→2SO3 (g)

The sulphite is dissolved in concentrated sulphuric acid to form oleum.

SO3 (g)+H2SO4 (aq)→2H2S2O7 (l)

The oleum is dissolved in calculated amount of water to give sulphuric acid.

H2S2O7 (l)+H2O(l)→2H2SO4 (aq)

It forms fumes.

Physical Properties

176. Concentrated sulphuric acid is a corrosive, oily and colorless liquid.
176. The concentrated acid is hydroscopic. I.e. When allowed in the atmosphere, it will absorb moisture and increase in volume.

Chemical Properties

• It is a strong dibasic acid. It reacts with alkalis to form carbonate and metals as a typical acid.
• Concentrated sulphuric acid is a dehydrating agent. It dehydrates blue hydrated copper II sulphate to white anhydrous copper II sulphate.

• Concentrated sulphuric acid is an oxidizing agent. It oxidizes copper I to copper II oxide.

• It also oxidizes carbon to carbon dioxide.

Uses of Sulphuric acid

•   It is used in making fertilizers. Eg (NH₄)₂SO₄.
•   It is used in paints and pigments.
•   It is used in synthetic fibersdetergents and dyes.
•   It is used in car batteries.
•   It is used in making dyes.