In a calorimetry trial, 2.50 g of NaCl (molar mass 58.44 g mol⁻¹) is dissolved in 100.0 g of water at 22.0 °C. A coffee-cup calorimeter with a heat capacity of 35.0 J °C⁻¹ is used. After dissolution, the temperature is 22.7 °C. Assume the specific heat capacity of the solution is 4.18 J g⁻¹ °C⁻¹. Determine the enthalpy change per mole of NaCl, ΔH (kJ mol⁻¹), for this process.