In the synthesis of sodium carbonate, the recovery of ammonia is done by treating NH4Cl with Ca(OH)2. The by-product obtained in this process is
Sodium carbonate is prepared from sodium by Solvay process. The equations in the process involved are as follows:
2NH3 + H2O + CO2→ (NH4)2CO3
(NH4)2CO3 + H2O + CO2→ 2NH4HCO3
NH4CO3 + NaCl → NH4Cl + NaHCO3
2NaHCO3→ Na2CO3 + CO2 + H2O
2NH4Cl + Ca(OH)2→ 2NH3 + CaCl2 + H2O
Carbon dioxide is passed through a concentrated solution of sodium chloride saturated with ammonia, which forms ammonium carbonate followed by ammonium hydrogen carbonate. Ammonium hydrogen carbonate crystals separate and they are heated to form sodium carbonate. NH3 is recovered from the solution which contains NH4Cl is heated and treated with Ca(OH)2. Calcium chloride is obtained as a by-product. The correct answer is (i).