In: Chemistry
a hydrated form of copper sulfate (cuso4·xh2o) is heated to drive off all the water if we start with 9.57 g of hydrated salt and have 7.15 of anhydrous CuSo4 after heating find the num. of water molecules associated with each CuSo4 formula unit
mass of hydrated salt ( CuSO4.xH2O) = 9.57g
mass of anhydrous salt ( CuSO4) = 7.15g
mass of water = mass of hydrated salt ( CuSO4.xH2O) -mass of anhydrous salt ( CuSO4)
= 9.57-7.15 = 2.42g
no of moles of CuSO4 = W/G.M.Wt = 7.15/159.5 = 0.0448moles
no of moles of H2O = W/G.M.Wt = 2.42/18 = 0.1344 moles
divide with lowest no of moles
CuSO4 : H2O = 0.0448 : 0.1344
= 0.0448/0.0448 : 0.1344/0.0448
= 1:3
There fore hydrate salt is CuSO4.3H2O