Gas Laws

1
Gas Laws
General Chemistry 101/102Laboratory
ManualUniversity of North Carolina at Wilmington
2
Gas Laws

• Purpose

• To study the relationships that exist among the
  properties of temperature, pressure, and volume
  for gases.
• To learn methods for measuring the temperature,
  pressure, and volume of gases.

3
Gas Laws

• Part 1 Boyles Law

• Open the Applications folder on your computer and
  double click on the Microlab Prompt as shown in
  the photo.

4
Gas Laws

• Part 1 Boyles Law

• Click on the Gas Laws prompt and then double
  click on the Boyles Law program to open up the
  file for the first part of the experiment.

5
Gas Laws

• Procedure Part 1 Boyles Law

• Obtain the plastic tubing and two syringes
  located in the ziplock bag labeled Gas Laws
  Experiment, located in the plastic container for
  Microlab Equipment.
• Disconnect the plastic tubing from the syringe.
  Connect the fitting of the tubing to the port
  labeled Pressure on the back of the Microlab
  kit as shown in the picture to the right.

6
Gas Laws

• Procedure Part 1 Boyles Law

• Obtain a syringe with a plunger and open the
  plunger up to the 10 mL mark.
• Now, re-connect the other end of the plastic
  tubing to the top of the syringe.

7
Gas Laws

• Begin data collection by clicking the Start
  prompt.
• While holding the plunger of the syringe steady
  at 10 mL, type in the value 10 in the keyboard
  input box.
• Click on Enter and Continue for the volume and
  pressure data to be collected.

8
Gas Laws

• Move the plunger to the 9 mL mark and type in
  this value in the input box, then press Enter
  and Continue.
• Set the plunger to subsequent volume settings
  (ex. 8, 7, 6, 5 and then up to 6, 7, 8, 9, 10,
  11, 12 and 13 mL).
• Press Enter and Continue while holding the
  plunger at each volume setting.

9
Gas Laws

• After you have completed your measurements, press
  the Stop prompt.
• Volume and pressure data will be available in the
  table below the graph, as in the photo shown.

10
Gas Laws

• Your graph will look similar to the one on the
  photo, where the red line indicates pressure on
  the y-axis (in units of torr) versus volume on
  the x-axis (in mL).
• (Ignore the blue line.)

11
Procedure Part 2 Pressure vs Temperature
Gas Laws

• Before beginning Part 2 of the experiment you
  will be asked if you would like to save the data
  from Part 1. Always click NO.

12
Part 2 Pressure versus Temperature
Gas Laws

• To begin the second experiment open the
  Applications and Microlab folders.
• Click on Gas Laws and then double click on the
  experiment labeled Pressure vs. Temperature
  Relationship-CHM 102.

13
Gas Laws

• Connect the temperature sensor to the temperature
  port A in front of the Microlab Kit.
• Remove the syringe with the plunger and attach
  the syringe containing the black stopper to the
  plastic tubing.

• Remove the rubber stopper from the syringe and
  then push it back in making sure it fits tightly.
• Use a rubber band to attach the temperature
  sensor to the syringe as shown in the photo.

14
Gas Laws

• Procedure Part 2

• Place the syringe in each water bath, starting
  with ice water, for two minutes.
• Record both the temperature and pressure readings
  observed for each water bath.

15
Gas Laws

• Procedure Part 2

• Click Continue when the syringe and temperature
  probe are immersed in the water bath.

16
Gas Laws

• Procedure Part 2

• Pressure and temperature values will be collected
  for each water bath.
• You may wish to collect data for combinations of
  water bath temperatures by adding some ice to the
  tap water, or to the hot water. This will give
  you more than just 3 data points for your
  experiment.

17
Gas Laws

• Procedure Part 2

• When you have finished data collection click the
  Stop prompt.
• A graph of pressure on the y-axis (in torr)
  versus temperature on the x-axis (in Celsius)
  will be drawn for you, similar to the one in the
  photo.