Question

Calculate the heat of hydration of MgSO4·7H2O if the enthalpy change for dissolving 1 mol of MgSO4 in water is -26.83 kJ/mol, and the enthalpy change for hydrating 1 mol of MgSO4·7H2O with 7 moles of water is -233.80 kJ/mol.

Answer 1

To calculate the heat of hydration of MgSO47H2O, we can use the following equation:Heat of hydration = Enthalpy change for dissolving MgSO4 + Enthalpy change for hydrating MgSO47H2OGiven:Enthalpy change for dissolving 1 mol of MgSO4 in water = -26.83 kJ/molEnthalpy change for hydrating 1 mol of MgSO47H2O with 7 moles of water = -233.80 kJ/molNow, we can plug these values into the equation:Heat of hydration =  -26.83 kJ/mol  +  -233.80 kJ/mol Heat of hydration = -260.63 kJ/molTherefore, the heat of hydration of MgSO47H2O is -260.63 kJ/mol.