3 Hydrated salt

Example 5. 3.51 g of hydrated zinc sulphate were heated and 1.97 g of anhydrous zinc sulphate were obtained. Use these data to calculate the value of the integer x in ZnSO4 .xH2O Calculate the mass of H2O = 3.51 – 1.97 = 1.54g Calculate moles of ZnSO4 Calculate moles of H2O 1.97 161.5 = 1.54 18 = = 0.0122 mol =0.085 mol Calculate ratio of mole of ZnSO4 to H2O 0.0122 0.0122 = 0.085 0.0122 =1 =7 = X = 7