Changes in State Lab10/23/06

Alex Wenner

General Question: What are some energy transformations that can be observed in the earth processes?

Materials:

Test tube Stearic acid Test tube holder Thermometer

Method:1. Obtain a heated tube of Stearic acid. Be careful not to burn your self while

walking back to your station holding the test tube with a test tube clamp. Place the test tube of stearic acid in a test tube holder. Record the initial temperature of the stearic acid with the thermometer that is in the test tube as quickly as possible.

2. Record the temperature of the stearic acid every 20 seconds (see data table) for 20 minutes. Pay very close attention to the test tube and make not of any changes and at what temperature those changes occurred

3. Graph the results of this investigation, and label the graph with the appropriate phases

Conclusion: There are changes of states like seen in this lab (liquid to solid) and there can be transfers of heat, etc.

Questions (Introduction):1. The molecules are close together and are vibrating slightly.2. The molecules have more room than in a solid and bounce around.3. It is freezing

Questions (Observations):1. 0-1:002. 4:40-10:00 it was freezing

Questions (Inference):1. The latent heat of fusion is the phase change from solid to liquid or liquid to solid.

It happened in this lab when the acid changed from liquid to solid.2. Because during a phase change the energy can not be lost but temperature can.

3.

3. Because that is where the gas is before it is turned to a vapor and therefore is much hotter than the liquid.

6. loses, warms, gains, absorbed7. It is being evaporated into the atmosphere.