The answer there is 12.3 kJ. First you have to calculate the amount of heat released (n) based on the given. Just multiply 36.8 grams of water to a mole of water per 18.015 grams, which will give you 2.04 moles of H2O. Using the formula heat released (q) = number for moles of the substance (n) multiplied to the molar enthalpy of fusion of the substance (H), you will have the (2.04 mole)(-6.01 kJ/mole), giving you an answer of -12.3kJ.