Discuss the various reactions that occur in the Solvay process

Explanation

In Solvay process, carbon dioxide is passed through a brine solution (about 28% NaCl) saturated with ammonia to give sodium bicarbonate.
`2NH_3 + H_2O + CO to underset("Ammonium carbonate") ((NH_4)_2CO_3)`
`(NH_4)_2CO_3 + H_2O + CO_2 to underset("Ammonium bicarbonate ")(2NH_4HCO_3)`
`NH_4HCO_3 + underset("Brine")(NaCl) to underset("Sodium bicarbonate (ppt.)")(NaHCO_3) + NH_4Cl`
The precipitated sodium bicarbonate is filtered and dried. It is ignited to give sodium carbonate.
`2NaHCO_3 + overset("Heat") underset("Sodium carbonate")(Na_2CO_3) + CO_2 + H_2O`
The carbon dioxide required for the reaction is prepared by heating limestone `(CaCO_3)` to about 1300 K in a lime kiln. Lime formed is dissolved in water to get calcium hydroxide which is transferred to the ammonia recovery tower.
`CaCO_3 overset("Heat")to underset("Calcium oxide (lime)")(CaO) + CO_2`
`CaO + H_2O to Ca(OH)_2`
Ammonia needed for the purpose is prepared by heating ammonium chloride obtained above with calcium hydroxide .
`2NH_4Cl + Ca(OH)_2 to 2NH_3 + CaCl_2 + 2H_2O`
Therefore , the only by product of the reaction is `CaCl_2` .