### *Purpose*

The purpose of this experiment is to measure how the evaporation of a
liquid affects temperature.

### *Performing the experiment*

1)  Read the temperature on the thermometer and record it in the table.

2)  Dip the thermometer bulb into the rubbing alcohol and remove it.
    Hold the thermometer, by its top, in your hand.

3)  After one minute, read the temperature on the thermometer and record
    it in the table.

4)  Wipe the thermometer bulb with a paper towel, and wait until the
    temperature on the thermometer has increased to almost room
    temperature.

5)  Now, repeat steps 1 to 4 using water instead of rubbing alcohol.

6)  Subtract the final from the initial temperature and record this
    difference in the table.

7)  Deposit your paper in the door prize drawing box.

### 

### 

### 

### 

### *Questions to think about*

1\) Did the evaporation of the rubbing alcohol cool the thermometer more
than the water?

2\) Does the alcohol evaporate faster than the water?

## *Explanation*

Evaporation is a cooling process because it removes heat from a
substance. Alcohol is a liquid that evaporates easily. When alcohol
evaporates, the molecules on the surface of the liquid can very easily
escape from the liquid into the air. Increasing the temperature of the
alcohol can increase the rate of evaporation. This makes the molecules
move faster and faster so that they can more easily escape from the
surface of the liquid. When the molecules evaporate, some of the energy
from the surrounding substance is transferred to the molecules.

  ----------------- ------------- ----------- ---------------- ------------- ----------- ----------------
                    **Rubbing                                  **Water**                 
                    Alcohol**                                                            

                    **Initial**   **Final**   **Difference**   **Initial**   **Final**   **Difference**

  **Temperature**                                                                        
  ----------------- ------------- ----------- ---------------- ------------- ----------- ----------------

# Student Name\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_

  ----------------- ------------- ----------- ---------------- ------------- ----------- ----------------
                    **Rubbing                                  **Water**                 
                    Alcohol**                                                            

                    **Initial**   **Final**   **Difference**   **Initial**   **Final**   **Difference**

  **Temperature**                                                                        
  ----------------- ------------- ----------- ---------------- ------------- ----------- ----------------

#### Student Name\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_

  ----------------- ------------- ----------- ---------------- ------------- ----------- ----------------
                    **Rubbing                                  **Water**                 
                    Alcohol**                                                            

                    **Initial**   **Final**   **Difference**   **Initial**   **Final**   **Difference**

  **Temperature**                                                                        
  ----------------- ------------- ----------- ---------------- ------------- ----------- ----------------

# Student Name\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_

  ----------------- ------------- ----------- ---------------- ------------- ----------- ----------------
                    **Rubbing                                  **Water**                 
                    Alcohol**                                                            

                    **Initial**   **Final**   **Difference**   **Initial**   **Final**   **Difference**

  **Temperature**                                                                        
  ----------------- ------------- ----------- ---------------- ------------- ----------- ----------------

# 

# Student Name\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_