Note: the sodium hydrogen carbonate formed is insoluble in the brine solution because of the common ion effect.
The overall reaction that occurs in the Solvay tower can be written as:
NaCl (aq ) + H2O(l) + NH3 ( aq ) + CO2 NaHCO3 (s) + NH4Cl( aq )
Stage 3 – Formation of Sodium Carbonate
The solid sodium hydrogen carbonate is filtered, washed and heated to dryness. When the temperature reaches 150 C, sodium hydrogen