Presence of water can be detected by

Presence of water can be detected by copper sulphate test. As we know, 4 2 .5 CuSO H O (copper sulphate pentahydrate) is blue in colour due to its 5 water molecules of crystallization. While anhydrous 4 CuSO is white in colour. Therefore, by the addition of water to anhydrous copper sulphate, it can be easily detected.