Question

Give reasons:

In the lab, preparation of ammonia calcium hydroxide is used in excess.

Answer 1

In the laboratory preparation of ammonia, calcium hydroxide is used in excess because it helps to completely liberate ammonia gas from ammonium chloride.

Excess of Calcium hydroxide (Slaked lime) is taken (Ratio by weight of Slaked lime & Ammonium Chloride taken is 3:2), as it can absorb the excess heat produced in this exothermic reaction and prevent the loss of Ammonium Chloride by Sublimation.