Question

Calculate the amount of energy required to melt 500 g of ice at 0oc. (δhfus=5.96 kj/mole; δhfus is the energy required to melt ice at a constant 0oc; note the units! )

Answer 1

When you want to melt an ice, you only need the latent energy of fusion, δhfus. We use the given value, then multiply this with the given amount to determine the amount of energy. Since the energy is per mole basis, use the molar mass of ice which is 18 g/mol. The solution is as follows:

ΔH = 5.96 kJ/mol * 1 mol/18 g * 500 g
ΔH = 165.56 kJ