Describe how washing soda is produced starting from sodium chloride(common salt). Write equations of all the reactions involved.

Sodium carbonate is manufactured by the thermal decomposition of sodium hydrogen carbonate.

NaCl + CO₂ + NH₃ + H₂O ⇨ NH₄Cl + NaHCO₃

The sodium carbonate obtained in this process is dry. It is called soda ash or anhydrous sodium carbonate. Washing soda is obtained by rehydration of anhydrous sodium carbonate.

Na₂CO₃ + 10H₂O ⇨ Na₂CO₃.10H₂O

Since there are 10 water molecules in washing soda, hence it is known as Sodium bicarbonate decahydrate.