The Solvay process is the major industrial process for production of sodium carbonate. When carbon dioxide gas is bubbled through a brine solution saturated with ammonia, sodium hydrogen carbonate is formed. This sodium hydrogen carbonate is then converted to sodium carbonate.

Various reactions of Solvay process are:

Step 1: CO₂ needed for reaction can be obtained by heating calcium carbonate and quick lime (CaO) is dissolved in water.

CaCO₃ (s) → CO₂ + CaO (II)

Step 2: Carbon dioxide is reacted with this ammonium hydroxide and Sodium Chloride to obtain Sodium Bicarbonate:

NH₃ + H₂O → NH₄OH

NaCl + NH₄OH + CO₂ → NaHCO₃ + NH₄Cl

Step 3: The solution containing crystals of NaHCO₃ is filtered to obtain NaHCO₃.

Step 4: NaHCO₃ is heated strongly to convert it into NaHCO₃.

2 NaHCO₃ (s) → Na₂CO₃ + CO₂ + H₂O (used again)

Na₂CO₃ + H₂O → Na₂CO₃.10H₂O

Reaction in one line:

NaCl + NH₃ + CO₂ + H₂O → NaHCO₃ + NH₄Cl