The heat of fusion for water is 6.01 kJ/mol and for ethyl alcohol is 5.01 kJ/mol.The amount of heat that would melt 25.0 grams of water would melt how many grams of ethyl alcohol?
A)76.7 g
B)53.3 g
C)11.7 g
D)8.2 g
E)30.0 g

Question

Quizplus · Accepted Answer

First, calculate the moles of water in 25.0 grams (molar mass of water = 18.015 g/mol), which gives approximately 1.387 moles. The heat required to melt this amount of water is 1.387 moles * 6.01 kJ/mol = 8.33 kJ. To find the mass of ethyl alcohol that can be melted with the same amount of heat, divide the total heat by the heat of fusion for ethyl alcohol (5.01 kJ/mol) to get the moles of ethyl alcohol, then multiply by its molar mass (46.07 g/mol) to get the mass in grams. This calculation yields approximately 76.7 grams.

The Heat of Fusion for Water Is 6