Calculate the smallest whole number ration of moles of water to moles of anhydrous salt.

Question

H₂O: 1.53g

= 8.5 x 10^-2 moles 

CuSo₄ : 0.87g

= 5.5 x 10^-3 moles

Answer 1

If your values are correct, and they may not be, the procedure to determine ratio of water to the anhydrous salt is..

moles H2O/moles anhydrous salt = 0.085/0.0055 = 15.5 = 16.  Water of hydration rarely exceeds 10:1 so this does not seem like the correct masses of water and anhydrous salt.  But, nonetheless, this is the procedure.