pricin banner

Questions & Answers

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

In this question, law of conservation of mass is used to calculate mass of water present.

                MgSO4.XH20 →MgSO4+H20

Mass of water of hydration= Mass of hydrated Magnesium Sulfate – Mass of Anhydrous      Magnesium Sulfate

Mass of H20 =3.210g-1.567g=1.643g

Moles of MgSO4= Mass of MgSO4/ Molecular Mass of MgSO4

                           = 1.567/ 120= 0.0131 mol

Moles of MgSO4.XH20= Moles of MgSO4= 0.0131 mol

Moles of H20 present in 0.0131 mol of Hydrated Magnesium Sulfate

= Mass of Water/ Mr of H20

= 1.643/18 = 0.0912 mol

Moles of Water present in 1 mol of Hydrated Magnesium Sulfate

= 0.0912mol/0.0131



Related Chemistry A-LEVELS answers