Action of heat on washing soda. Observations and identification of gas.

Dear Student,

Sodium Carbonate - Na₂CO₃.10H₂O
Na₂CO₃.10H₂O $\stackrel{∆}{\to }$ Na₂CO₃ + 10H₂O (water vapor)
If it is strongly heated, then, Na₂CO₃ → Na₂O + CO₂
Carbon dioxide is evolved and identified by lime water test.
CO₂ + Ca(OH)₂ $\to$CaCO₃ + H₂O. Milkiness appears. This confirms carbon dioxide.

​​​​​​​Regards