Low Temperature and Non-ideal Behavior of Gases

When the temperature is very low, the particles of the gas slow down.

As a result of this, they move past each other more slowly and collide more slowly. This increases the amount of time that the particles have to act on each other. As a result, any attractions that exist between the particles will be more important as the temperature drops.

In this text we will call this the South Street Effect and it is described elsewhere in the text.

As a result of the South Street Effect, lower temperatures lead to a loss of energy when particles collide with each other (the collisions become sticky).

This, in turn, means that the particles will hit the walls with less force, exerting less pressure.

So, as the temperature goes down, the pressure drops faster than would be predicted by the equations used earlier in the unit.

Gases are also non-ideal at high densities...