# Question #eb1dc

$C u S {O}_{4} o 5 \left({H}_{2} O\right)$. The mole ratio of water to the entire molecule is 5 moles ${H}_{2} O$/1 mole $C u S {O}_{4}$. The mass ratio is 90g/159.5g or 0.564 (56.4%). The amount of water in the entire molecule is 90/249.5 = 0.36 or 36%.