Experiment No. 1 Exercise No 1 - Heating and Cooling.pptx

Thermodynamics Lab

1. HEATING AND COOLING Experiment No. 1

2. Introduction In this experiment, an example of the different mechanisms of heat transfer will be observed. A bowl/cup of water will be used. The cup/bowl is set on a gas stove, and the gas stove is turned on. Heat transfer can be observed. The gas stove transfers heat to the cup/bowl, and the cup/bowl transfers heat to the water at the bottom of the cup/bowl. This is conduction. Heat is then transferred through convection when the hot water at the bottom moves to the top. If the heat source is shut off or removed, thermal energy is being radiated by the water until the water reaches room temperature. The amount of heat added, the mass, and the specific heat of water all affect how quickly the water would heat up.

3. Learning Outcomes At the end of the experiment, the student must be able to: 1. Measure temperature and mass using SI units. 2. Make and use graphs to describe the change in temperature of water as it heats up and cools down. 3. Explain the similarities and differences in these two changes.

4. Materials Gas stove (or any kind of burner/cooker) Aluminum cup (outer vessel of the calorimeter) 150mL of water 2 thermometers Stopwatch (or timer) Weighing scale

5. Procedure Measure the mass of your cooking bowl or cup. Pour approximately 150 mL of water into your cooking bowl and measure the combined mass of the water and the bowl/cup. Calculate the mass of the water inside the bowl/cup. Record this in the data table. Measure the initial temperature of the water. Make sure that the bulb end of the thermometer must not touch the bottom or sides of the bowl/cup. Measure the temperature of the air in the room. Take care that the bulb end of the thermometer must not touch a table or your hands.

6. Procedure 6. Turn on the gas stove. 7. Place the bowl/cup with water on the stove. 8. Record the temperature of the water inside the bowl/cup every minute for five (5) minutes. 9. Turn off the gas stove. Carefully remove the bowl/cup from the stove. 10. Record the temperature of the water inside the bowl/cup every minute for the next ten minutes. 11. At the end of the ten minutes, record the temperature of the air in the room. 12. When finished, allow all the equipment to cool and dispose of the water carefully.

7. T able 1. Data Table for the Measurement of the Mass of Water and Air Temperature. Mass of water   Initial water temperature   Initial air temperature   Final air temperature   Change in air temperature  

8. Time (min) Temperature (◦C)                     Table 2. Temperature of Water for Heating

9. Time (min) Temperature (◦C)                                     Table 3: Temperature of Water for Cooling