Classical Gases

Ideal gas

Equipartition Theorem

Each independent square, average value equals to

Diatomic gas

Define: - - -

So: However, successive freezing of vibration and rotation modes! Quantum effect at temperature ~ K

Vibration

Partition function: Heat capacity: Define characteristic temperature: - High temperature limit: - Low temperature limit:

Rotation

Partition function: Define characteristic temperature: - High temperature limit: - Low temperature limit:

Interacting gases

Virial Expension: (expension in small parameter n) Compute :