1. Physical Characteristics of Gases
The Kinetic Molecular Theory of Matter

2. Objectives List the physical properties of gases
Use the KMT to explain the physical properties of gases.

3. Kinetic Molecular Theory of Gases
KMT- The particles of matter are in constant motion.
Ideal Gas – a gas that behaves according to the kinetic molecular theory.

4. Kinetic Molecular Theory of Gases
Gases are made up of tiny particles.
- Usually atoms or molecules

5. Kinetic Molecular Theory of Gases
The particles of a gas are far apart from each other.
The volume of gas particles is insignificant relative to the space between the particles

6. Kinetic Molecular Theory of Gases
The particles of a gas are in constant motion and collide with each other and the walls of their container.
The collisions are elastic; no K.E. is lost.
Collisions exert a force -pressure
Specian's Phun machines: Ideal gas – YouTube

7. Kinetic Molecular Theory of Gases
The particles of a gas do not exert any force on each other except when they collide.

8. Kinetic Molecular Theory of Gases
Temperature is a measure of the average kinetic energy of the particles of a gas.
Kinetic Energy in a Gas - YouTube

9. Kinetic Molecular Theory of Gases
Summary
Gases are composed of particles.
The particles of a gas are far apart from each other.
Particles in constant motion  collisions  pressure.
No forces between particles (except in collisons).
Temp. is a measure of avg. kinetic energy.

10. Properties of Gases Expansion of gases No definite shape or volume
Expand to fill their container

11. Properties of Gases
Fluidity of Gases
Gases have the ability to flow.

12. Properties of Gases
Low Density 1 mole of 20oC: 18 mL 1 mole of 120oC and 1 atm: 22.4 L

13. Properties of Gases
Compressibility
Gases can be easily compressed

14. Properties of Gases
Diffusion and Effusion Diffusion –mixing of particles due to random motion of particles Effusion – process in which gases past through a tiny opening

15. Deviations from Ideal Gas Behavior
At low temperatures and high pressures, gases do not follow ideal gas behavior.
The volume of the particles is significant.
Intermolecular forces become important.
Real gas – one that does not behave according to the KMT