Answer:
36.0%.
Explanation:
The mass of water = mass of hydrated copper (II) sulfate - mass of copper (II) sulfate after heating = 4.56 g - 2.92 g = 1.64 g.
The percent by mass of water in the hydrate = (mass of water/mass of hydrated copper (II) sulfate)*100 = (1.64 g/4.56 g)*100 = 35.96% ≅ 36.0%.
