- Gases are composed of particles that move randomly in straight lines, colliding elastically with each other and the container walls. The average kinetic energy of gas particles depends on temperature. - Boyle's law states that the pressure and volume of a gas are inversely related at constant temperature. Charles' law says volume and temperature are directly related at constant pressure. - Students are reminded to bring materials for experiments on gas laws, including syringes, balloons, water, and thermometers. Problems involving Boyle's and Charles' laws are assigned.

2. P R E S S U R E

3. T E M P E R T U R E
A

4. V O L U M E

5. H E A T

6. Gas Laws:
Pressure, Volume,
and Temperature

7. Opening thoughts…
Have you
ever:
Seen a hot air balloon?
Had a soda bottle spray all over you?
Baked (or eaten) a nice, fluffy cake?
These are all examples of gases at work!

8. Properties of Gases
You can predict the behavior of
gases based on the following
properties:
Pressure
Volume
Amount (moles)
Temperature

9. Properties
and
Measuring
Variables
Gases

10. Characteristics of Gases
Kinetic Molecular Theory
 Gases are composed of a large number
of particles that behave like hard,
spherical objects in a state of constant,
random motion.
 These particles move in a straight line
until they collide with another particle or
the walls of the container

11. Kinetic Molecular Theory
 These particles are much smaller than
the distance between particles. Most of
the volume of the gas is therefore empty
space
 There is no force of attraction between
gas particles or between the particles
and the walls of the container

12. Kinetic Molecular Theory
 Collisions between gas particles or
collisions with the walls of the container
are perfectly elastic.
 The average kinetic energy of a
collection of gas particles depends on
the temperature of the gas and nothing
else.

13. STP
Standard Temperature & Pressure
0°C 273.15 K
1 atm 101.325 kPa
-OR-
STP

14. II. The Gas Laws
BOYLE’S
CHARLES
GAY-LUSSAC’S
The LAWS

15. A. Boyle’s Law- Robert Boyle
P
V
Volume
(mL)
Pressure
(torr)
P·V
(mL·torr)
10.0 760.0 7.60 x 103
20.0 379.6 7.59 x 103
30.0 253.2 7.60 x 103
40.0 191.0 7.64 x 103

16. A. Boyle’s Law
The pressure and volume
of a gas are inversely
related
• at constant mass & temp
P
V
P V = P V
1 1 2 2

17. A. Boyle’s Law Equation
A 2.0 L party balloon at 98kPa is
taken to the top of the mountain
where the pressure is 75 kPa.
Assume the temperature is the
same. What is the new volume of the
balloon?

18. A. Boyle’s Law Equation
Given:
P1= 98 kPa
V1= 2.0 L
P2= 75 kPa
V2=
P1V1=P2V2
____ ____
P2
P2
= 98 kPa. 2.0 L
___________
75 kPa
= 196 kPa.L
___________
75 kPa
= 2.61 L
2.61 L
2.0 L
98 kPa
75 kPa

19. V
T
B. Charles’ Law- Jacques Charles
Volume
(mL)
Temperature
(K)
V/T
(mL/K)
40.0 273.2 0.146
44.0 298.2 0.148
47.7 323.2 0.148
51.3 348.2 0.147

20. V
T
B. Charles’ Law
The volume and absolute
temperature (K) of a gas
are directly related
• at constant mass &
pressure
V V
T T
=
1
1
2
2

21. A. Charles Law Equation
A gas inside the cylinder with a
movable piston is to be heated to
315ºC. The volume of gas in the
cylinder is 0.30L at 25ºC. What is the
final volume?

22. 1. Boyle’s Law Equation
A weather balloon containing 35.0L
of helium at 98kPa is released and
rises. Find out the volume of the
balloon when the atmospheric
pressure is 25.0kPa?

23. 2. Charles Law Equation
An open 2.05L plastic pop container
is removed from a refrigerator at 5°C
and allowed to warm up to 21°C on a
kitchen counter. What volume of air
will leave the container as it warms?

24. I have learned that ……

25. Assignment
1. A 325 ml of Chlorine under a pressure of 680 mmHg
are placed into a container under the pressure of 1210
mmHg. What is the volume of the container?
Solve the following problems involving
Boyle’s and Charles Law
2. A balloon contains 7.2 L of He. The pressure is
reduced to 2 atm and the balloon expands to occupy a
volume of 25.1 L. What was the initial pressure exerted
on the balloon?
3. Calculate the decrease in temperature when 2.0 L at
20ºC is compressed to 1.0 L?
4. At 27ºC a gas has a volume of 6.0 L. What will the
volume be at 150ºC?

26. Reminder!
Bring the following materials
to be used for tomorrow’s
experiment:
Group 1 and Group 3
1. 25 ml syringe
2. Ruler
3. Glue stick
4. Two 1/8 Illustration board
5. Glue gun
6. Marker and White Cartolina

27. Reminder!
Bring the following materials
to be used for tomorrow’s
experiment:
Group 2 and Group 4
1. Rubber Balloon
2. Tap Water
3. Hot Water
4. Cold Water
5. Thermometer
6. Tape Measure
7. Marker and White Cartolina

28. Gas Laws:
Pressure, Volume,
and Temperature