# Measurement of the specific latent heat of fusion of ice

When ice, at zero degrees celsius, is added to warm water, it first melts and then its temperature increases as it takes heat from the water. If this occurs in an insulated container then the heat gained by the ice is equal to the heat lost by the container and the water. The specific latent heat of fusion of ice (l) can then be calculated using the formula:

mi l + mi cw (rise in temp of melted ice) = mc cc (fall in temp of calorimeter) + mw cw (fall in temp of water)

where mi, mc and mw are the masses of ice, calorimeter and water respectively and cw and cc are the specific heat capacities of water and of the material of the calorimeter.

Procedure:
1. To select a calorimeter click on the word "Copper" for other options. Mass is shown in the top pan balance.

2. Click in the Mass box and select the mass of water in the calorimeter. (min.50g, max. 90g). Press Submit.

3. Click on "Place Calorimeter" to put the calorimeter in the insulated container.

4. Record the starting temperature, mass of water, mass of calorimeter, and the material of the calorimeter.

5. Press "Add Ice" to add dry crushed ice to the water in the calorimeter.

6. After a temperature fall of 10 to 15 degrees, the temperature stops falling.

7. Press "Get Total Mass" to find the mass of calorimeter + water +ice. Record.

8. Press "Reset".

9. Repeat the experiment using a variety of calorimeters and masses of water.

Mass water:

Precautions:

• Ensure that only ice (not water) enters the water in the calorimeter. The melting ice should be dabbed with abosrbent paper.
• Ensure that the calorimeter is well insulated to avoid loss or gain of heat energy.
• Stir the water throughout the experiment to ensure that the thermometer reading reflects the actual temperature.
• Use a sensitive thermometer graduated to 0.1 or 0.2 degrees. An error of 1 deg. in 10 is a large relative error.
• Use warmed water (about 5 deg. above room temp.) at the start of the experiment so that, overall, heat is neither lost nor gained from the surroundings.

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