Que. Discuss the various reactions involved in the Solvay process.
Ans. In the Solvay process.
When carbon dioxide is passed through a concentrated solution of brine saturated with NH3, NaHCO3 gets precipitated. NaHCO3 on subsequent heating gives Na2CO3.
NaCl + NH3 + CO2 + H2O → NaHCO3 + NH4Cl
2 NaHCO3 → Na2CO3 + CO2 + H2O
CO2 needed for the reaction is prepared by heating calcium carbonate and the quick lime, CaO is dissolved in water to form slaked lime, Ca(OH)2
CaCO3 → CaO + CO2
CaO + H2O → Ca(OH)2
NH3 needed for the purpose is prepared by heating NH4Cl and Ca(OH)2
2 NH4Cl + Ca(OH)2 → 2 NH3 + CaCl2 + H2O