When 0.794 g of NH4NO3 was added to 150.0 g of water in a Styrofoam cup, the temperature dropped by 0.413°C. The heat capacity of H2O is 4.18 J/g°C. Assume the specific heat of the solution equals that of pure H2O and that the calorimeter neither absorbs nor leaks heat. The molar heat of solution of solid NH4NO3 is:
