When you are ready to activate the animation click the Start button in the animation rectangle.

What you will observe is plot of the temperature change for a sample of H2O, initially at -10 degrees Celsius being heated using a Bunsen burner. As heat is added we record the temperature change the sample of water experiences. At the end of the plot five numbered rectangles will appear. It is these rectangles that are referred to in the questions below. When the animation finally stops answer the questions. It is OK to view the animation more than once, just click on the Repeat button.

Important do not press the enter key or the Return key while you are answering these questions. Your Browser will interpret either key the same as clicking the mouse on the Submit button. So BE CAREFUL!

Give me some responses to the questions below and I'll give you some extra credit.

SID#:

Laboratory Section:

1. In general what happens to the temperature of the sample of H2O as heat is added?

Expert:

The temperature of the sample generally increase as heat is added. Interestingly there are two temperatures where the addition of heat does not change the temperature.

2. What phase is the sample of H2O at the beginning of the experiment before any heat is added?

Expert:

The H2O is in the solid phase at the beginning of the experiment.

3. There are two plateaus in the graph (#2 and #4). What is the temperature at plateau #2? #4? What is happening at each of these plateaus?

Expert:

At the first plateau the temperature is 0 degrees Celsius. This is the melting point for water. At the left most point on this plateau the sample is all solid at 0 degrees Celsius. As heat is added (moving to the right on the horizontal line) the solid H2O melts. At the right most point on the plateau at 0 degree Celsius the sample is all liquid.

At the second plateau the temperature is 100 degrees Celsius. This is the boiling point for water. At the left most point on this plateau the sample is all liquid at 100 degrees Celsius. As heat is added (moving to the right on the horizontal line) the liquid H2O vaporizes. At the right most point on the plateau at 100 degree Celsius the sample is all vapor.

4. What is the phase of the sample of H2O along the line identified as #3? What is happening to the temperature of the sample of H2O along this line?

Expert:

The phase along the line identified as #3 is liquid only. This line begins at 0 degrees and ends at 100 degrees. So the temperature is increasing as we move from lower left most point on the line to the upper right most point.

5. Can you define specific heat for me? If so write your definition below. If you are not sure if you understand specific heat try answering the following questions.

Expert:

Specific heat is the amount of heat required to change the temperature of 1 gram of a substance by 1 degree Celsius. Notice that specific heat includes the term 'change the temperature'. When we look at the heating curve the lines identified at #1, #3 and #5 indicate the temperature is changing. The lines #2 and #4 are plateaus. Those horizontal lines have constant temperature, so heat required to change the phase does not have a specific heat value associated with it.

6. Is there anything about this animation that you feel you do not understand? List your concerns/questions.