1.034 g of a metal sulfate hydrate (if you have not heard of hydrates, look up online or in your lecture course textbook) was he
ated to a high enough temperature to remove all the water of hydration. The mass of the anhydrous salt left behind was found to be 0.956 g. What is the mass percentage of water in the hydrate?
A hydrate is a salt that has molecules of water incorporated into the crystals. It is represented by the molecular formula of the salt followed by how many molecules of water it has: XY.nH₂O.
So, the mass of water in the sample will be the difference between the hydrate and the salt without water:
mass of water = 1.034 - 0.956 = 0.078 g
The mass percentage is the mass of water divided by the total mass, and then multiplied by 100%:
