Determine the formula of copper nitrate crystalline hydrate if 0.7504 g of copper (II) nitrate was formed from 0.966 g

Determine the formula of copper nitrate crystalline hydrate if 0.7504 g of copper (II) nitrate was formed from 0.966 g of it after the loss of crystallization water. (Cu (NO3) 2 * 3H2O)

Mr (Cu (NO₃) ₂) = 64 + 17 * 2 = 188;
Let the molecular weight of the crystalline hydrate be x.

0.7504 / 188 = 0.966 / x;

x = 0.966 * 188 / 0.7504 = 242.

Let’s find the molecular weight of water in crystalline hydrate 242-188 = 54;

Mr (H₂O) = 18;

The number of H2O molecules in the crystalline hydrate: 54/18 = 3;

This means that the formula of the crystalline hydrate is: Cu (NO₃) ₂ * 3 H₂O.