Calculate the percentage of water of crystallization in $CuS{O}_4.5H_{2}O$?

[H=1, O=16, S=32, Cu=64].

Copper sulphate is hygroscopic by nature. When copper sulphate and water interact, a hydrated version of the salt is created. Pentahydrate copper sulphate is created when copper sulphate combines with five water molecules.

The molecular weight of water$=2 \left(1\right) +16=18 g/mol$ 

The Molecular weight of $CuS{O}_4.5H_{2}O$ $= 64+32+4\left(16\right)+5\left(18\right)= 250g/mol$

The percentage of water of crystallization-

${\mathrm{CuSO}}_4.5{\mathrm{H}}_2\mathrm{O}=\frac{5\times 18}{250}\times 100=36\%$
 

Hence, the percentage of water of crystallization is 36%.