Introduction:
Boyle's Law states that at a constant temperature the volume of a gas is inversely proportional to the pressure. That is, as the volume of the gas decreases, the pressure increases. The mathematical relationship is given by PV = k: pressure (P) times the volume (V) equals a constant (k). How can you determine this constant for different gases? How does changing the pressure exerted on a gas affect its volume? Let's find out!

Standard Setup 1:

Procedure:

How does changing the volume of a container of gas affect the pressure?

Remember, Boyle's Law states that the product of the pressure and volume of a gas equals a constant. The mathematical relationship is shown below:

PV = k

How do we determine this constant?

1. Open the Toolbar and select a piston chamber, a nitrogen tank, a pressure gauge, and two connecting tubes.

2. Attach one connecting tube to the lower left side of the piston chamber and to the pressure gauge.

3. Attach the other connecting tube to the lower right side of the piston chamber and to the nitrogen tank.

4. Add 10 liters of nitrogen to the piston chamber. Click on the gas tank's silver button to release the gas.

5. Measure and record the pressure and volume.

6. Open the Toolbar and select a 50-kg mass and a Magic Meter.

7. Place the mass on the piston.

8. Record the new volume using the Magic Meter.

9. Record the pressure.

How has increasing the pressure of the gas affected the volume?

10. Add an additional 50-kg mass. Record the pressure and volume.

11. Repeat step 10 three more times.

12. Calculate the product PV for all your data. Does PV appear to be a constant?

13. Try this experiment using another gas (make sure you use the same initial volume). Will you get the same value for k?

To answer the questions pertaining to this experiment, click on the Questions button.

EXPERIMENT 1: Boyle's Law/Standard Setup 1

Questions:

Select the best answer or the answer closest to your calculated value.

1. The relationship between volume and pressure can be stated as
a) volume increases as pressure increases
b) volume decreases as pressure decreases
c) volume decreases as pressure increases
d) there is no relationship between volume and pressure

2. The value you calculated for k after placing the first 50-kg mass on the piston is
a) 10.0 l atm
b) 7.9 l atm
c) 0.1 l atm
d) 0.5 l atm

3. The average value for k is
a) 8.5 l atm
b) 0.5 l atm
c) 7.5 l atm
d) 10.0 l atm

4. Volume and pressure are
a) not proportional
b) inversely proportional
c) directly proportional

5. If the gas exerts a pressure of 7.5 atm and the value of k is 2.2 l atm, the volume of the gas is
a) 0.1 l
b) 16.5 l
c) 0.3 l
d) 3.4 l

6. As the pressure increases inside the chamber, the value of k
a) increases
b) decreases
c) becomes zero
d) stays the same

7. If k had a value of 5 l atm, the pressure inside the chamber at the start of this experiment would be
a) 0.3 atm
b) 0.5 atm
c) 0.8 atm
d) 1.0 atm

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