The molar heat of fusion for water is 6.01 kj/mol. how much energy is released when 36.8 g of water freezes at its freezing point?

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.

4d^55s^1 ( third choice)