Discuss the various reactions that occur in the Solvay process

Explanation

Solvay process is used to prepare 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.
Step 1: Brine solution is saturated with ammonia.
`2NH_(3)+H_(2)O+CO_(2)rarr (NH_(4))_(2)CO_(3)`
This ammoniated brine is filtered to remove any impurity.
Step 2: Carbon dioxide is reacted with this ammoniated brine to result in the formation of insoluble sodium hydrogen carbonate.
`NH_(3)+H_(2)O+CO_(2)rarrNH_(4)HCO_(3)`
`NaCl+NH_(4)HCO_(3)rarr NH_(4)HCO_(3)downarrow +NH_(4)Cl`
Step 3: The solution containing crystals of `NaHCO_(3)` is filtered to obtain NaHCO3.
Step 4: NaHCO3 is heated strongly to convert it into NaHCO3.
`2NaHCO_(3)rarr Na_(2)CO_(3)+CO_(2)+H_(2)O`
Step 5: To recover ammonia, the filtrate (after removing NaHCO3) is mixed with Ca(OH)2 and heated.
`Ca(OH)_(2)+2NH_(4)Clrarr LNH_(3)+2H_(2)O+CaCl^(2)`
The overall reaction taking place in Solvay process is
`2NaCl+CaCO_(3)rarrNa_(2)CO_(3)+CaCl_(2)`