The number of water molecules present in a molecule of copper sulphate crystal is

The colour of copper sulphate crystal is

White crystalline solid of calcium (A), is sparingly soluble in water and solubility decrease when temperature increases. It dissolves in ammonium sulphate due to the formation of double salt. The number of water molecules perestent in one molecule of the double salt is _____.

The number of water molecules is maximum in

What is the number of water molecules present in a Ferrous Sulphate crystal ?