the chemical formula for washing soda is - Na₂CO₃.10H₂O

It is prepared by heating baking soda and then recrystallizing the product so obtained.

The equations related to the above reaction are:-

2NaHCO₃ Na₂CO₃ + H₂O + CO₂

Na₂CO₃ + 10H₂O → Na₂CO₃.10H₂O

Two applications of washing soda are:-

1. It is used in glass, soap and paper industries

2. It is used for removing permanent hardness of water.