When a finely crushed mixture of dry solid ammonium chloride and slaked lime (calcium hydroxide) is heated in the ratio of 2:1, they react with each other to release ammonia gas.

\(\rm 2NH_{4}Cl \)+\(\rm Ca(OH)_{2} \) → \(\rm CaCl_{2} \) + \(\rm 2H_{2}O\)+\(\rm 2NH_{3} \)