Describe The Difference Between Hydrate And Copper Sulfate

A hydrate is any compound that contains water in the form of H2O molecules and usually has a definite content of water by weight. Hydrates typically have a crystal like appearance that can vary in colour and have a naming scheme based on the compound and number of water molecules that are in the hydrate. Copper(II) sulfate pentahydrate, or CuSO4 * 5H2O, is a ratio of one copper sulfate to five (penta) molecules of water. Copper sulfate pentahydrate is a blue hydrate while anhydrous copper sulfate (CuSO4) is white. To get anhydrous copper sulfate, copper sulfate pentahydrate must go through an endothermic reaction and have all of its water molecules evaporated. It then becomes the white, flaky, and chalky material anhydrous copper sulfate. Adding
water back to the anhydrous material will reform it into a hydrate. Hydrate have fairly simple formulas. They are the anhydrous material multiplied by the amount of water molecules. For example cobalt(II) chloride hexahydrate, a deep purple colour, is CoCl2 * 6H2O. CoCl2 or anhydrous cobalt chloride is a sky blue and is simply just without the water molecules that the hydrate form has. Such a small change as adding water to the compound changes the colour drastically. The point of the experiment done in class was to calculate the molar mass of the anhydrous solution of a compound and to figure out what the ratio of water molecules the hydrous solution had. By massing the compound before and after evaporating the water through heating calculating the moles of water and the compound would be possible. To figure out the empirical formula of the compound, we would have to calculate the ratio. By getting the mass of the water (through evaporation) we could figure out how many moles there were and then by using the amount of moles of the the compound we could figure out the ratio. Simply dividing both values by the smaller one would provide us with the ratio of water to salt.