Question

When an ideal gas undergoes free expansion, no cooling occurs since the molecules

• A. are above the inversion temperature.
• B. exert no attractive forces on each other.
• C. do work equal to loss in kinetic energy.
• D. collide without loss of energy.

Answer 1

The correct option is B exert no attractive forces on each other.

An ideal gas has no intermolecular attractive forces. When it expands against vacuum, no work is done so that temperature is unaffected.