Question

How is an acid prepared from a

(a) Non-metal

(b) Salt?

Give an equation for each.

Answer 1

Acids are prepared from non-metals by their oxidation. 

For example :

Sulphur or phosphorus is oxidized by conc. Nitric acid to form sulphuric acid or phosphoric acid.

S + 6HNO₃ H₂SO₄ + 2H₂O + 6NO₂

P + 5HNO₃ H₃PO₄ + H2O + 5NO₂

Acids are prepared from salt by displacement reaction. 

For example :

Nitric acid is prepared by using H2SO4 and sodium chloride.

NaCl + H₂SO₄ NaHSO₄ + HNO₃