How many grams of water in 8.22 grams of cuso4*5h2o?

Molar mass of CuSO4 * 5 H2O

= 63.546 + 32 + 16*4 + 5*18

= 249.546 g/mol

Mass of water in that formula: 5 * 18 = 90 g/mol

Percent by mass of water = 90 / 249.546 = 36%

So, 36% of your 8.22 g is water. 0.36 * 8.22 = 2.95 g of water