Question

If the pressure in a closed vessel is reduced by drawing out some gas, the mean-free path of molecules :

• A. is decreased
• B. is increased
• C. remains unchanged
• D. increases or decreases according to the nature of the gas

Answer 1

The correct option is B is increased

The mean-free path of molecule is the distance traveled by a molecule in two consecutive collision. If pressure is reduced and there are less particle then a molecule will travel longer distance before collision, so mean free path is increased.