Heating 3.210g of hydrated magnesium sulfate, MgSO4.XH2O, forms 1.567g of anhydrous magnesium sulfate. Find the value of X and write the formula of the hydrated salt

We need to find the value of X (the water of crystallisation) and to do this we can start by calculating the moles of water lost and the moles of the anhydrous salt (the salt product without water), we do this to establish a molar ratio and consequently deduce the formula of the hydrated salt. Step 1: Calculating moles of water lost:mass of water lost: 3.210 - 1.567 = 1.643g moles of water lost: mass/molar mass: 1.643 / 18 = 0.0913 molesStep 2: Calculating moles of anhydrous salt:molar mass of MgSO4 = 120gmol^-1number of moles: m/molar mass: 1.567/120 = 0.0131 molesStep 3: Calculate molar ratio between anhydrous salt and water0.0131 moles of salt : 0.0913 moles of water1 moles of salt : 0.0913/0.0131 = 6.97 moles of water rounded to 7X must be a whole number so we round 6.97 up to 7 and the formula thus is: MgSO4.7H2O where X = 7