2. Experiment to develop the relationship between the pressure and volume of a gas.
Include: Boyle’s Law
Experiment to develop the relationship between the volume and temperature of a gas.
Include: Charles’ Law, Absolute zero, Kelvin scale, ideal gas
Additional KEY Terms
Inverse relationship
Direct relationship

3. BOYLE’S LAW:
The volume of a given amount of gas (held at a constant temperature) varies inversely with the pressure.
P α 1 V

4. BOYLE’S LAW – Pressure vs. Volume
Pressure (kPa)
Volume (mL)

5. What will be the volume of 40 L of gas (held at a constant temperature) if the pressure is doubled? Reduced to 1/3rd ?
P α 1 V
2 α 1 2
20 L
1/3 α 1
1/3
1 = 3
1/3
120 L

6. P α 1 V
PV = k =
P2V2
P1V1

7. 6 atm of pressure will change 3 L of a gas at 1 atm to 0.5 L.
If 3 L of gas is initially at a pressure of 1 atm, what would be the new pressure required for a volume of 0.5 L? =
P1V1
P2V2
(1)(3) P2
(0.5) =
6 atm of pressure will change 3 L of a gas at 1 atm to 0.5 L.

8. A syringe contains 20 mL of a gas at 100 kPa
A syringe contains 20 mL of a gas at 100 kPa. The pressure in the syringe is changed to 25 kPa. What is the new volume of the gas? =
P1V1
P2V2
(100)(20)
(25) V2 =
The gas will expand to 80 mL.

9. Absolute Zero

10. An increase of 273°C, doubled the volume.
Jacques Charles ( )
Volume of gas changed with only 1oC change in temperature.
An increase of 273°C, doubled the volume.
CHARLES’S LAW:
Volume of a given gas (held at a constant pressure) varies directly with the temperature
V α T

11. CHARLES’S LAW – Temp vs. Volume
Volume (mL)
Temperature (oC)

12. Stated as “315 Kelvin”- no degrees.
William Thomson ( )
Created Kelvin Scale where –273°C is the lowest temperature possible or Absolute Zero.
“Hypothetical” – called an ideal gas model:
predicts that with zero kinetic energy comes zero volume.
TK = TC TC = TK - 273
Stated as “315 Kelvin”- no degrees.

13. engaged in random motion (normal) obey conservation of energy (normal)
Ideal Gas Model:
engaged in random motion (normal)
obey conservation of energy (normal)
non-interacting particles
Most real gases behave like “ideal gases,” but
formula fails at lower temperatures OR higher pressures.
(IMFs alter results)

15. **All temperatures must be in Kelvin.
V α T
V = k T = V1 V2 T1 T2
**All temperatures must be in Kelvin.

16. What is the new volume of a gas if 100 mL of the gas at 25°C is cooled to –25°C?= V2
100
-25 V2 = T1 T2 25
25°C = 298 K –25°C = 248 K
(248)
100 =
83.2 mL
298
The new volume is 83.2 mL.

17. If the volume of a gas at –73°C is doubled to 48
If the volume of a gas at –73°C is doubled to 48.0 L, calculate the final temperature in degrees Celsius.
–73°C = 200 K V1 = V2 T1 T2
400 K =
48.0
(200)
24.0
400 K – 273 = 127°C

18. Boyle described the inverse relationship between the pressure and volume of a gas at a constant temperature.
Charles described the direct relationship between the temperature and volume of a gas at a constant pressure.
William Thomson (Lord Kelvin) developed the Kelvin temperature scale.
At zero Kelvin (absolute zero) , the volume of a gas will theoretically be zero.
When solving gas problems the temperature must always be converted to Kelvin.

19. CAN YOU / HAVE YOU?
Experiment to develop the relationship between the pressure and volume of a gas.
Include: Boyle’s Law
Experiment to develop the relationship between the volume and temperature of a gas.
Include: Charles’ Law, Absolute zero, Kelvin scale, ideal gas
Additional KEY Terms
Inverse relationship
Direct relationship