Question

A blue coloured salt becomes white on heating. Give reason for the above
observation. What happens when we add water to the salt which is obtained after
heating? Also write its formula

Answer 1

Explanation:

The blue salt is hydrated copper sulphate (CuSO4. ... 5H2O), which loses its water of crystallization and becomes white anhydrous copper sulphate (CuSO4) upon heating it. On adding water, the anhydrous form again becomes hydrated and the blue colour is regained.