Topic 5: One-Page Revision Sheet

Chapter 9: Kinetic Theory of Gases – One Page Revision

1. Kinetic Theory of Gases

Explains behaviour of gases based on continuous random motion of gas molecules.

2. Basic Assumptions

• Gas consists of large number of tiny molecules
• Molecules are in continuous random motion
• Volume of molecules is negligible
• No intermolecular forces between molecules
• Collisions are perfectly elastic

3. Pressure of a Gas

Pressure is due to collision of gas molecules with container walls.

Pressure = Force / Area

SI unit: Pascal (Pa)

4. Kinetic Energy of Gas Molecules

Gas molecules possess kinetic energy due to random motion.

Average kinetic energy per molecule:
(3/2) k T

Average kinetic energy per mole:
(3/2) R T

5. Relation with Temperature

• Kinetic energy ∝ absolute temperature
• Same for all gases at same temperature
• Minimum at absolute zero (0 K)

6. Important CET Points

• Assumptions of kinetic theory
• Origin of gas pressure
• Formula for average kinetic energy
• Relation between kinetic energy and temperature