Lab 6: Latent Heat and Specific Heat



Specific Heat

  1. Suppose you place a hot piece of metal in a styrofoam cup containing some water. By how much will the temperature of the water increase? Try this out with one of the known pieces of metal. Then calculate the expected temperature rise as done in example 10.3 on page 145.
  2. Repeat the experiment with another piece of metal. Based on the temperature rise you observe, what is the specific heat of the metal?


Latent Heat

Let's calculate the latent heat of boiling for water.

  1. Pour some water into a beaker. Measure the mass of the beaker with the water in it.
  2. Place the beaker on a hot plate and put a thermometer in the water. Measure the temperature of the water once every thirty seconds. Record the temperature readings.
  3. Eventually the water will come to a boil. Keep making the temperature readings for another 5 minutes or so.
  4. Take the beaker off the flame. Be careful not to burn yourself. Measure the mass of the beaker again. It should be lighter since a bunch of the water will have boiled away.
  5. Based on how much mass was boiled and a knowledge of how long the water was boiling, you should be able to calculate the latent heat.


Power and Heat

  1. Measure a small amount (maybe .5 L) of water and put it in the hot pot. Let the water and the pot reach equilibrium and measure the temperature of water.
  2. Hook the hot pot up so that it's running through the power meter.
  3. Turn the hot pot on. Every 30 seconds measure the temperature of the water and the energy that's gone into the hot pot.
  4. What fraction of the energy flowing into the hot pot goes to heating the water?
  5. Now you know how much thermal energy is going into the water every 30 seconds. You should be able to use this information to predict how quickly a given mass of water will boil away, once It's reached 100 degrees. Make a prediction and test it.


[Dave] [Physics I] [COA]

Web page maintained by dave@hornacek.coa.edu.