1. The Gaseous State
Chapter 10

2. Kinetic Theory Kinetic energy is the NRG of motion
The Kinetic Theory states that all particles of matter are in constant motion

3. Assumptions of Kinetic Theory in relation to gases:
Gases are composed of small, hard spheres with an insignificant volume
They are far apart with empty space in between

4. 3. There are no attractive or repulsive forces between the particles
4. The particles move rapidly and are in constant motion
5. They travel in straight paths independently of each other

5. 6. Gases fill their container indefinitely (they will expand)
7. Only change direction after colliding with something else
8. All collisions are perfectly elastic – no energy loss

6. The kinetic theory is helpful in explaining gas pressure
Gas pressure: force exerted by a gas on its container
An empty space with no particles = vacuum = no pressure

7. Atmospheric pressure – the pressure of air around earth – dependent on the weather
Barometers measure air pressure

8. SI Unit of pressure is the pascal (Pa)
At sea level, Atm. Pressure is kilopascals (kPa)
mmHg and atmospheres (atm) are older units of pressure
1atm = 760mmHg = 101.3kPa

9. The standard conditions to relate measured values to are 1atm (101
The standard conditions to relate measured values to are 1atm (101.3kPa) and 0oC, or STP – this is important when discussing gases and gas pressure

10. When a substance is heated, the particles store some of the absorbed NRG (potential) but the NRG not stored increases the speed of the particles, the average kinetic NRG & the temperature

11. The actual particles have a wide range of kinetic energies – but temperature is the average kinetic energy
At high temperatures, there is a wider range of kinetic NRGs

12. As a substance cools, the particles lose energy & slow down
Absolute Zero (0K, -273oC) theoretical temperature when no movement occurs = no NRG

13. Check out this website tutorial on the States of Matter, from CHEMTUTOR.com
Click HERE
for Tutorial

14. Now, move on to the Phase Changes Power Point
Click Here to go
on to the
Phase Changes
Power Point