When a solid dissolves in water, heat may be evolved or absorbed. The heat of dissolution (dissolving) can be determined using a coffee cup calorimeter. In the laboratory a general chemistry student finds that when 0.90 g of MgCl,(s) are dissolved in 117.70 g of water, the temperature of the solution increases from 22.94 to 26.11 °C. The heat capacity of the calorimeter (sometimes referred to as the calorimeter constant) was determined in a separate experiment to be 1.69 J/°C. Based on the student's observation, calculate the enthalpy of dissolution of MgCl,(s) in kJ/mol. Assume the specific heat of the solution is equal to the specific heat of water.

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