Magnesium sulfate is often used in first aid hot packs because it gives off heat when dissolved in water. A coffee cup calorimeter contains 15.0 ml of water at 25°C. A 2.00g sample of magnesium sulfate is dissolved in the water and 1.51 kJ of heat is released. The specific heat of water is 4.184 J/g°C. Is the dissolving of MgSO₄ exo- or endothermic?