Question

Distinguish by a chemical test, ammonium sulphate and sodium sulphate.

Distinguish between the following pair of compounds using a reagent as a chemical test:

Ammonium sulphate crystals and Sodium sulphate crystals.

Answer 1

These salts can be distinguished by using KOH. When KOH is added to ammonium sulphate, ammonia gas is evolved. Whereas there is no evolution of ammonia gas in the case of sodium sulphate.

Answer 2

Ammonium sulphate with NaOH produces NH₃ ↑.

\[\ce{(NH4)2SO4 + 2NaOH ->[\Delta] Na2SO4 + 2H2O + 2NH3}\]

Meanwhile, sodium sulphate with NaOH does not produce ammonia gas.