Question

Convert i) NaHCO3. ii) NaCO3 to unstable carbonic acid by action with dil H2SO4. State the reason why ammonia is evolved when an ammonium salt and alkali are heated.

Answer 1

i) 2NaHCO₃ + H₂SO₄ → Na₂SO₄ + 2H₂CO₃
​ii) Na₂CO₃ + H₂SO₄ → Na₂SO₄ + H₂CO₃

When ammonium salt is heated in the presence of an alkali,decomposition of the salt takes place wherein the bond between the cation and the anion breaks giving off ammonia gas.
NH₄Cl + NaOH → NH₃ + NaCl + H₂O