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Lesson: Heat of Fusion

Learn how the mass melted when heating an object consisting of a substance at its melting point depends on the heat entering the object and the object's latent heat of fusion; conversely, the mass frozen depends on the heat leaving an object.

Worksheet: Heat of Fusion • 6 Questions

Q1:

To help prevent frost damage to a fruit tree, 4.00 kg of water at is sprayed onto the tree and allowed to freeze. The specific latent heat of fusion of water is 334 kJ/kg.

How much heat transfer occurs as the water freezes?

The tree has a mass of 200 kg and a specific heat capacity of . How much would the temperature of the tree have decreased if it had not been sprayed by water, assuming that no state changes occur in the matter of the tree as it cools?

Q2:

An ice cube has a mass of kg. The ice cube is placed inside a perfectly insulated container that holds 0.400 kg of water at an initial temperature of . Find the final temperature inside the container. Use a value of for the specific heat capacity of water and 334 kJ/kg for the specific latent heat of fusion of water.

Q3:

A bag containing ice at a temperature of is much more effective in absorbing energy than a bag containing the same amount of water at a temperature of . The specific heat capacity of water is and the specific latent heat of fusion of ice is 334 kJ/kg.

How much heat transfer is necessary to raise the temperature of 0.800 kg of water from to ?

How much heat transfer is necessary to melt of 0.800 kg of ice at and then increase its temperature to ?

Q4:

A 0.800-kg iron cylinder at a temperature of is dropped into an insulated copper container of mass 1.50 kg, that contains 0.500 kg of ice at its melting point. The container is in thermal equilibrium with the ice. The specific heat capacity of copper is . The specific heat capacity of iron is . The specific latent heat of fusion of ice is 334 kJ/kg.

What is the final temperature of the container and its contents?

Q5:

An iron cylinder has a mass of 0.80 kg and a temperature of . The cylinder is dropped into an insulated chest containing 1.0 kg of ice at its melting point. What is the equilibrium temperature of the chest’s contents? Use a value of for the specific heat capacity of water, a value of 334 kJ/kg for the latent heat of fusion of water, and a value of for the specific heat capacity of iron.

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