An ideal gas expands into a vacuum in a rigid vessel. As a result there is:
A) a change in entropy
B) an increase of pressure
C) a change in temperature
D) a decrease of internal energy
E) a change in phase

Question

Quizplus · Accepted Answer

The expansion of an ideal gas into a vacuum in a rigid vessel is an example of a free expansion, which is an irreversible process. During this process, there is no work done on or by the gas since the volume does not change (rigid vessel), and there is no heat exchange with the surroundings (assuming adiabatic conditions). However, the entropy of the gas increases because the gas molecules have more accessible microstates in the larger volume, leading to a higher degree of disorder. The pressure, temperature, and internal energy of the ideal gas remain constant, and there is no phase change involved.

An Ideal Gas Expands into a Vacuum in a Rigid