Q.Write balanced chemical equations for the following.
CO2 is passed into concentrated solution of NaCl, which is saturated with NH3.

Sodium carbonate, washing soda, Na2CO3.10H2O, is manufactured by the Solvay process. First, CO2 is passed into a concentrated NaCl solution saturated with NH3, forming ammonium bicarbonate in solution, which then undergoes a double-decomposition reaction with the dissolved sodium chloride to precipitate the comparatively less-soluble sodium bicarbonate: NH4HCO3(aq) + NaCl(aq) → NH4Cl(aq) + NaHCO3(s). Heating these NaHCO3 crystals gives sodium carbonate, 2NaHCO3 →(Δ) Na2CO3 + H2O + CO2. The ammonia used is recovered and reused by treating the leftover NH4Cl with slaked lime, Ca(OH)2, which regenerates NH3 and produces CaCl2 as a byproduct — this ammonia recycling is what makes the process economical. (Potassium carbonate cannot be made the same way, because potassium bicarbonate is too soluble to precipitate out.) Sodium carbonate itself is a highly water-soluble white solid that loses its water of crystallisation on heating (first to the monohydrate, then above 373 K to an …