A. Visit the Gas Laws web site and answer the following questions:

1. State the four variables that are commonly used to quantify a gas.
 

Variable
Name	Symbol

2. State the following gas laws in equation form using the above symbols and give an example or device that uses each law.
 

	Law	Example
Boyle's law
Charles's law
Gay-Lussac's law

B. Pressure sensor check   

Equipment needed: PC, interface, and pressure sensor.

1) Look at the pressure sensor and find out the following:

    a. What type (absolute or gauge) of pressure it measures?_________________

    b. Range of pressure it can measure?________________  

2) Connect the pressure sensor to analog channel A on the Interface.

3) Open DataStudio. Click 'Create Experiment', Double-click Pressure Sensor (Absolute), and click Digits display.

4) Click Start and measure the atmospheric pressure.

            Atmospheric pressure = _______________________

5) Is the above atmospheric pressure reasonable? Explain._____________________________________

 _________________________________________________________________________________  

_________________________________________________________________________________  

C. Boyle's law: Pressure vs. Volume              

Equipment needed: PC, interface, pressure sensor, and syringe.

1)         Connect the pressure sensor to analog channel A on the Interface.

2)         Open DataStudio.  Select “Open Activity”, select "Library", select Physics Labs, and open “P18 Boyle’s Law”.

3)         Take the syringe, and pull out the piston to the 20 ml mark.

4)         Line up the quick-release connector with the corresponding end of the pressure sensor.  Push it in and turn it clockwise until you hear a small click.

5)         Double click on the Volume and Pressure Table icon under the displays list on the left side of the screen.

6)         One of you need to hold the syringe and change the volume and another person need to collect the data. Click the Start button.

7)        Check to make sure that the syringe position is still at 20 ml, and Click once on the Keep button.

8)     Make sure that the corresponding syringe volume reads “20”.  If it does not, click once on the box and type in the correct value.

9)     Push the piston of the syringe until it reaches the 19 ml mark and click once again on the Keep button.

10)     Again, change the corresponding syringe volume to 19. 

11)     Continue decreasing the volume by 1 ml and taking measurements each time until you reach 10 ml.

12)     Click on the Stop button.

13)     Double click on the Volume vs. Pressure graph and examine it. Do the pressure and volume seem to be directly or inversely proportional? Does this agree with Boyle’s Law?

_________________________________________________________________________________________

        _________________________________________________________________________________________

14)     Go back to the volume and pressure data table and high-light the volume column. (move the mouse arrow in the title cell and left-click). Click Edit and copy the volume column. Open a blank excel page and paste the volume data. Delete the time column. 

15)    Do the same as 14 for the pressure column. 

16)   Close the Data Studio window, without saving. 

17)     In the Excel page, create two more columns, one for 1/V and the other for PV. Plot P versus 1/V and print a hard copy of the graph and data table. Does your results verify Boyle's law?

________________________________________________________________________

________________________________________________________________________

________________________________________________________________________

18)  What are possible sources of error or limitations in this experiment?  Include some suggestions for improvement.

________________________________________________________________________

________________________________________________________________________

________________________________________________________________________

________________________________________________________________________

D. Gay-Lussac's law: Pressure versus Temperature

Purpose: To investigate the relationship between the pressure of a gas and the temperature of a gas when its volume is kept constant and determine the value of the absolute zero temperature. 

Apparatus: Pressure sensor, temperature sensor, PC w/interface, hot plate, magnetic stirrer, beaker(500-ml), stand w/clamp, flask with rubber stopper and connector, water, and ice.

Procedure: 

1. Place the stirrer in the beaker and place the flask inside the beaker. Fill the beaker with  some ice & water mixture, and put the beaker on the hot plate. Do not turn on the hot plate now. 

2. Attach the flask to the clamp of the stand so that it will be submerged in the ice-water mixture.

3. Connect the temperature sensor to analog channel A and place the probe in the ice-water mixture. 

4. Connect the pressure sensor to analog channel B, and to the connector-tube that connects to the flask.

5. Open "DataStudio", select "Open Activity", select "Library", select "Physics Labs", and select P17, Pressure versus Temperature. 

6. Click on the Pressure and Temperature Table display, and click "Start". 

7. Click "Keep" to collect the first temperature and pressure data.

8. Turn on the heat and stirrer on the hot-plate and watch the temperature.

9. When the temperature reaches about 8-9 degrees, click "Keep" to collect the data again. 

10. Continue collecting data, about every 10 degree temperature change, and until the water boils. It is important that the water is stirred well during the experiment. Stop the data collection at the end. 

11. Use the graph display to determine whether or not the relationship between pressure and temperature is linear.
Is the relationship between the pressure and temperature linear or not?

    ______________________________________________________________ 

12. Click 'Fit' and select 'Linear' from the menu. Use the fit to estimate the value of absolute zero. This is done by clicking the zoom out button until the x-axis is visible. 

Absolute zero temperature (experimental) = ________________

Absolute zero temperature (accepted)    =  ________________

                                    % Error             = _________________


E. Charles's Law: Volume vs. Temperature

In order to verify Charles' law we will visit the following Java site.  As you increase the temperature, the volume will increase and it will also fluctuate. We will collect three volume data and find the average volume. Set  N= 30, P =30.

Plot the Average Volume versus Temperature, print a hard copy of the graph, and describe how your results verify Charles's law.