To measure the heat capacity of mozzarella cheese.
Equipment:
Insulating styrofoam cup, thermometer, heater, glass beaker, stopwatch, ~ 200 gm of water, ~100 gm of mozzarella cheese.
Procedure:
Heat about 200 gm of water in a glass beaker to the temperature specified by the instructor. (Each group will start with a different water temperature.) Determine the mass of the mozzarella and measure its temperature. The cheese should be near room temperature.
When the water is near the specified temperature, pour it into the styrofoam cup and quickly replace the cover. Gently push the thermometer through the straw hole in the lid and record the temperature of the water.
Quickly place the cheese into the cup and gently stir with the thermometer. DO NOT stir quickly! The thermometer can be easily broken.
Record the temperature every 30 seconds for about five minutes. It will take time for the cheese and water to reach equilibrium. Look at the values for the temperature as you record them. If the recorded temperatures are still erratic after 5 minutes, keep stirring and recording until it "levels off". If in doubt, keep taking data and ask the instructor for advice.
Once the temperature is no longer changing erratically, you may notice the temperature slowly falling. Some heat may be escaping through the walls of the cup during this time. Discuss within your group ways in which to account and correct for this problem.
Using conservation of heat energy, determine the specific heat of the mozzarella. (It will be more accurate to determine the mass of the water by subtracting the masses of the mozzarella and the empty cup from that of the cup + contents.)
Conclusion:
The specific heat determined by each group, as well as the temperature ranges for their specific experiment, will be posted on the board. Analyze the specific heat values determined by all groups to determine whether or not there are any trends related to the temperatures at which the experiments were performed? You may wish to try a plot to help you identify those trends.