Question

Integral enthalpy of a solution of KCl when 1 mole of it is dissolved in 20 mole water is +15.90kJ. when 1 mole of it is dissolved in 200 mole water, the change in enthalpy is 15.58kJ. Calculate the enthalpy of hydration.

Answer 1

The enthalpy of hydration is the change in enthalpy, when a solution containing 1 mole of a solute is diluted from one concentration to another.
dH hyd = 18.58 - 15.90 = 2.68 kJ