When water was added to a white anhydrous substance X, the colour changed to blue. X is

A. CuSO4
B. FeSO4
C. Na2SO4
D. PbSO4

Correct Answer: Option A

A. CuSO4

Explanation

When water is added to white coloured anhydrous copper sulphate, its colour changes to blue, indicating that the blue coloured copper sulphate pentahydrate is regenerated.