A blue coloured salt of copper sulphate becomes white on heating. Give reason.

Copper Sulphate exists in two forms. One form is the hydrated copper sulphate whose chemical formula is CuSO4.5H2O and hydrated copper sulphate is blue colour in appearance.

When hydrated copper sulphate is heated, the water molecule gets evaporated to form anhydrated copper sulphate which is white in colour.


CuSO4.5H2O CuSO4 + 5H2O


When we add water externally to anhydrate copper sulphate, it again turns blue in colour.



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