When a 3.00 g sample of KCl is dissolved in water in a calorimeter that has a total heat capacity of 1.413kjk-1 the temperature decreases by 0.490K calculate the molar heat solution of KCl?

To calculate the molar heat of solution of KCl, we first determine the heat absorbed by the calorimeter using the formula ( q = C \Delta T ), where ( C ) is the heat capacity and ( \Delta T ) is the temperature change. Here, ( q = 1.413 , \text{kJ/K} \times 0.490 , \text{K} = 0.69337 , \text{kJ} ). The number of moles of KCl in a 3.00 g sample (molar mass of KCl = 74.55 g/mol) is ( \frac{3.00 , \text{g}}{74.55 , \text{g/mol}} \approx 0.0402 , \text{mol} ). Therefore, the molar heat of solution is ( \frac{0.69337 , \text{kJ}}{0.0402 , \text{mol}} \approx 17.24 , \text{kJ/mol} ).