Question

Calculate the percentage of water of crystallisation in green vitriol.

Answer 1

The chemical formula of $FeS{O}_4.7H_{2}O$
$=55.8+32.1+16\times 4+7\times 18=277.9$
The percentage of water of crystallization=
$=\frac{7\times 18}{277.9}\times 100\%=45.34\%$