3. Some ionic compounds are hydrates - solid compounds to which is bound a specific percentage of
water. Some hydrates melt when heated and release energy when they solidify. For example, at
32°C, liquid Glauber's salt - sodium sulphatedecahydrate, Na2SO4. 10H2O(l) - solidifies and releases
78.0kJ/mol of energy. Calculate the enthalpy change when 2.50kg of Glauber's salt enters the solid
state? (ans: -605kJ]