Question

Calculate ΔHfus of water, in kJ/mol, by dividing the heat transferred from the water by the moles of ice melted.

Heat transferred from water = -8.01 kJ

Moles of ice melted = 1.3432 mol

I got -10.75 kJ/mol. Could someone explain what this means?

Edit: wrong I got -5.96 kJ/mol

Answer 1

The heat which a solid (ice here) absorbs when it melts is called the enthalpy of fusion or heat of fusion.

When ice melts a large amount of energy can be absorbed by the ice in the form of potential energy. So if you talk about all the energy that the ice is asborbing, most of it is due to the heat of fusion (5.96 kJ/mol here). You can actually have zero degree ice and it can still absorb this huge amount of energy just by melting it, without even changing its temperature.

So, your answer -10.75 kJ/mol is higher than expected (5.96 kJ/mol) dut to addition of potential energy absorbed by ice.