Name _________________________________________________ Date ____________ Period _______
Boyles and Charles Law Labs
Boyle’s Law describes the relationship between pressure and volume of a gas and Charles Law describes
the relationship between volume and temperature of a gas.
Purpose: To determine graphically the relationship between pressure and volume (Boyle’s Law) and
Volume and Temperature (Charles Law). In these two labs you will collect data in two different
experiments and graph the results to determine the relationships described above. One relationship is a
linear relationship. This means as one variable changes the other changes in a direct relationship. The
other is an inverse relationship. As one variable changes the other changes exponentially (more rapidly).
Boyles Law Lab
Hypothesis: (hint-which law will show a linear relationship and which will show an exponential
relationship?) _________________________________________________________________________
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Materials: 35 ml syringe, dish soap, sealed rubber stopper, wooden base and top, 12 books
Procedure:
1.) Place the syringe into the wooden block marked “base”. Push in the plunger until the volume
in the barrel is 35 ml. Place the wooden block marked top on top of the syringe. Your Boyles law
apparatus is now ready.
2.) Record the initial volume with no pressure pushing down on the syringe. This is 35 ml. Next
place one book on top of the wooden block. Record the new volume. Add one book at a time and
continue recording the changes in volume until you have placed a total of 10 books on top of the block.
Be careful not to let the pile of books fall over and land on your hand. You may get hurt. Two people
are needed to balance the books on the syringe.
3.) Plot the data on your graph and draw a smooth curve through the point on your graph.
Data Table:
# of Books
Zero
One
Two
Three
Four
Five
(Pressure)
Trial #1
35 mL
Volume in mL
# of Books
Six
Seven
Eight
Nine
Ten
(Pressure)
Trial #1
Volume in mL
Results: explain any pattern in the numbers ________________________________________________
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Conclusion: __________________________________________________________________________
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Graph of Boyles Law or a graph of Pressure verses ____________
1.) What two variables are graphed in the Boyles Law experiment?
2.) Which of the three variables that affect a gas is held constant?
3.) Predict what the volume of the gas would be if 15 books were used.
4.) Does this experiment show a direct relationship or an inverse relationship?
5.) Does the data show a constant change between pressure and volume? Explain your answer.
6.) Would the graph have a similar shape if you varied the volume of the gas instead of the pressure?
Charles Law Lab
Purpose: In this lab you will determine the relationship between volume and temperature of a gas as the
gas is cooled. What do you expect to happen to the gas volume as the gas is cooled?
Hypothesis: (hint-which law will show a linear relationship and which will show an exponential
relationship?) _________________________________________________________________________
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Materials: syringe, ring stand, beaker, test tube clamp, water, thermometer, ice.
Procedure: Set up the ring stand and test tube clamp. Raise the test tube clamp so that you can place a
beaker on the ring stand base and the test tube clamp can hold the syringe in place. Adjust the volume of
the syringe to 35 ml. Attach the test tube clamp to the plunger of the syringe and lower the syringe into
the beaker. Make sure the volume in the syringe is still 35 ml. Your teacher will fill the beaker with
boiling water. Bubbles will start to come out of the syringe. Put in a thermometer set to Celsius. Wait
until the temperature decreases to 85 oC. When the water reaches 85oC begin adding one piece of ice at a
time to the water to lower its temperature. Stir the water constantly. Add small bits of ice and do the
experiment SLOWLY!! As the temperature of the gas in the syringe drops water will begin to fill the
syringe. When the temperature of the water in the beaker reaches 80oC begin recording the volume of the
gas in the syringe. Subtract the amount of liquid from the original 35mL to get the volume of the gas. At
every 5 degree drop in temperature record the volume of the gas in the syringe. (Keep subtracting the
volume of the water in the syringe from 35 ml) Continue to add ice slowly. Continue to record the
temperature of the water every 5 oC as long as time allows. If the beaker gets to full use a small beaker to
remove some water so the addition of more ice will not cause the water in the beaker to overflow.
Data Table:
Temperature of H2O in oC
80oC
75oC
70oC
65oC
60oC
55oC
50oC
45oC
40oC
Volume of Gas ml
Temperature of H2O in oC
35oC
30oC
25oC
20oC
15oC
10oC
5o C
Volume of Gas ml
Results: explain any trend in the data ___________________________________________________
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Conclusion: be sure to restate your hypothesis, use the results to support your conclusion and tell if the
hypothesis was correct. _________________________________________________________________
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Graph of Charles Law or a graph of Volume verses ________________.
1.) Does the graph of Charles Law show a linear or non-linear relationship?
2.) If the water was cooled to 1 degree Celsius above freezing predict the volume of the gas.
3.) What three variables must be considered when doing experiments with a gas?
4.) Which variable for Charles Law is held constant?
5.) What is the slope of the line obtained in this experiment?
6.) What are the units for the slope of this line?