A student adds 4.20 g of KOH pellets (molar mass 56.11 g mol⁻¹) to 150.0 g of water initially at 21.4 °C in a coffee-cup calorimeter. The final temperature of the solution is 25.0 °C. Assume the specific heat capacity of the solution is 4.18 J g⁻¹ °C⁻¹ and that the calorimeter itself absorbs negligible heat. Calculate the molar enthalpy change, ΔH (kJ mol⁻¹), for the dissolution of KOH as performed in this experiment, including the appropriate sign.