1. Volume - Temperature:
Charles’ Law

2. OUTCOME QUESTION(S): C11-2-07 UNITS AND RELATIONSHIPS
Describe the various units used to measure pressure and convert between units.
Include: atmospheres, kilopascals, millimetres of mercury
Experiment to develop the relationship between the pressure and volume of a gas using visual, numeric, and graphical representations.
Include: Boyle’s Law
Experiment to develop the relationship between the volume and temperature of a gas using visual, numeric, and graphical representations.
Include: Charles’ Law, Absolute zero, Kelvin scale, Ideal gas
Develop the relationship between the pressure and temperature of a gas using visual, numeric, and graphical representations.
Include: Gay-Lussac’s Law, Dalton’s Law
Vocabulary & Concepts 

3. Volume and temperature show a constant direct relationship
Jacques Charles: ( )
Experimented with volume and temperature of a sample at constant pressure.
Data plotted – as volume vs. temperature
Linear relationship emerges (a straight line)
Slope is constant and predictable
rise = constant
run V
= constant T
rise
Volume and temperature show a constant direct relationship
run

4. Predictions fail using negative Celsius temperatures
William Thomas: ( )
Also known as “Lord Kelvin”
Recognized significance of the extrapolation…
Created Kelvin Scale where 0 K represents the lowest possible temperature (–273°C)
Called Absolute Zero
Predictions fail using negative Celsius temperatures

5. Absolute temperature extrapolations lead to:
Ideal Gas Model
Predicts that with zero kinetic energy comes
zero volume
Suggest particles will be non-interacting
not possible
not true
Model predictions are good approximations of real gas behaviours under normal conditions – fail at extreme low temperatures or high pressures

6. (when held at a constant pressure)
Charles’ Law:
The volume of a given amount of gas varies directly with the temperature in Kelvin.
(when held at a constant pressure)
V α T

7. Stated as “315 Kelvin”- no degrees
Converting Kelvin scale - Celsius:
TK = TC TC = TK - 273
Stated as “315 Kelvin”- no degrees
Now solve Charles’ Law by converting to Kelvin and use the same ratio argument used in Boyle’s Law problems

8. What is the new volume of 40 L of gas if the temperature in Kelvin is doubled?
A direct relationship suggests:
2 α 2
V α T
80 L
Double the temperature will double
the original volume
If temperature is reduced to 1/3rd ?
1 3 α 1 3
13.3 L
Decreased temperature will shrink
volume to 1/3 the original
Direct of a third is a third

9. = V1 T1 V2 T2 V1 T1 V2 T2 Charles’ Law Equation: V = constant T
rise
run
**All temperatures must be in Kelvin.
V = constant T V1 T1 V2 T2
Initial conditions always equal Final conditions when divided

10. What is the new volume of a gas if 100 mL of the gas at 25°C is cooled to –25°C?
V1 = 100 mL
T1 = 25oC = 298 K
V2 = ?
T2 = -25oC = 248 K
Watch units… V1 = V2
Predicted result? T1 T2
(248)
100
83 mL =
298
Decreasing the temperature by 50 degrees will cause a decrease in volume to 83 mL

11. 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.
V1 = 24 L
T1 = -73oC = 200 K
V2 = 48 L
T2 = ? V1 = V2 T1 T2
Predicted result? =
48.0
(200)
400 K
24.0
400 K – 273 = 127°C
Doubling volume will require doubling temperature (in Kelvin) or 127oC

12. CAN YOU / HAVE YOU? C11-2-07 UNITS AND RELATIONSHIPS
Describe the various units used to measure pressure and convert between units.
Include: atmospheres, kilopascals, millimetres of mercury
Experiment to develop the relationship between the pressure and volume of a gas using visual, numeric, and graphical representations.
Include: Boyle’s Law
Experiment to develop the relationship between the volume and temperature of a gas using visual, numeric, and graphical representations.
Include: Charles’ Law, Absolute zero, Kelvin scale, Ideal gas
Develop the relationship between the pressure and temperature of a gas using visual, numeric, and graphical representations.
Include: Gay-Lussac’s Law, Dalton’s Law
Vocabulary & Concepts