Background : Boyle’s Law - If a gas is in a sealed container (______is constant) and the temperature is kept constant, then increasing the pressure should result in a(n) ______in volume; or a decrease in the pressure should result in a(n) ______in volume.

Procedure: For this lab you will apply an increasing force (pressure) to a sealed syringe (______of gas is constant). After adding each additional book (up to a total of 5 books), you will record the volume of the gas in the syringe. Assuming that each Chemistry book has a mass of 2.2 lbs (1.0 Kg), determine the pressure applied to the gas in the syringe.

# of Volume Surface area of Applied pressure Applied Pressure

books (liters) syringe (m2) (lbs./in2) (kPa)

0 books

1 book

2 books

3 books

4 books

5 books

Using EXCEL or other graphing software, plot the volume vs. pressure (kPa) for the above data. Make certain to include the appropriate title and make certain that you label the axis correctly.

1) Show how you calculated the area of the syringe in m2:

2) Show how you calculated the final pressure in kPa:

3) Calculate Boyle’s Law constant for this data.

4) What type of relationship exists between the pressure and volume of a gas in a sealed container at constant temperature? ______What type of graph should you observe when plotting your results? ______

Background : Charles’ Law – If a gas is in a sealed container (______is constant) and the pressure is kept constant, then increasing the temperature should result in a(n) ______in volume; or a decrease in the temperature should result in a(n) ______in volume.

Procedure:

·  For this lab, you will heat the air inside a 125 ml Erlenmeyer flask. This will be done by immersing the flask into a beaker of boiling water.

·  Measure the temperature of the boiling water. Record this as the initial temperature of the gas.

·  After boiling the water (heating the gas inside the flask) for a time of at least 2 minutes, you will seal the flask (to keep ______of gas constant) using a wooden or rubber stopper.

·  You will then carefully remove the sealed flask from the water and immerse that flask into a sink filed with water.

·  Measure the temperature of the water in the sink. Record this as the new temperature of the gas.

·  After doing this, remove the stopper and watch water flow into the flask (reduced volume due to the reduced temperature of the gas).

·  After keeping the flask in the water for a period of about 2 minutes, pull the flask up toward the surface of the water. When the water levels are equal (this assures that the pressure inside the flask is the same as the pressure outside the flask), re-seal the flask and remove from the water.

·  Measure the volume of water pulled into the flask. Record.

·  Measure the total volume of the flask. Record this as the initial volume of the gas.

·  Calculate the new volume of the gas by subtracting the volume of water pulled into the flask from the total volume of the gas.

·  Repeat this procedure a second time and record all data in the table below.

Data: Trial 1 Trial 2

Initial temperature of gas (T1) (oC) ______

Initial temperature of gas (T1) (K) ______

Initial volume of gas @ T1 (V1) ______

New temperature of gas (T2) (oC) ______

New temperature of gas (T2) (K) ______

Volume of water pulled into flask ______

New volume of gas @ T2 (V2) ______

Calculations:

BEFORE removing the flask from the boiling water, from the initial temperature of the gas (the temperature of the boiling water), the initial volume (total volume of the flask), and the new temperature of the gas (water temperature in the sink), determine what you would expect V2 (new volume of the gas) to be.

Trial 1:

Trial 2:

Using EXCEL, plot the Kelvin temperatures versus the volume of gas. Make certain to set the x-axis (temperature) scale to begin at zero Kelvin. Make certain to include the appropriate title and make certain that you label the axis correctly.

Questions:

1)  Which trial yielded the best results? ______Explain how you know this to be true.

2)  Using your best data, calculate Charles’ Law constant.

3)  Using your actual and expected new volumes, calculate the % error of your results. Do this for both trials. The results here should support what you chose as your answer to question #1 above.

4) What type of relationship exists between the temperature and volume of a gas in a sealed container at constant pressure? ______What type of graph should you observe when plotting your results? ______