How many water molecules in blue vitriol are coordinated to the metal ?

Options

A. Five
B. Four
C. Three
D. Two

Answer

B

Explanation

The crystalline copper (II) sulphate, `CuSO_(4)` . `5H_(2)O`, has the structure in which four water molecules are coordinated to the central copper catio9n at the centre of a square but the fifth water molecule is held by hydrogen bonds between a sulphate ion and a coordinated water molecule. The fifth hudrogen bonded water molecule is deeply embedded in the crystal lattice and hence not easily removed: `[Cu(H_(2)O)_(4)]^(2+) SO_(4)^(2-).H_(2)O`