A 40.0-L container is divided into two equal parts by a rubber membrane. One half of the container has 1.50 moles of an ideal monatomic gas at 250 K, and the other half is a vacuum. The container is well insulated, so there is no exchange of heat with the surroundings. The membrane breaks, and eventually the gas reaches a new equilibrium condition occupying the entire volume. What is the final temperature of the gas?
A) 100 K
B) 125 K
C) 157 K
D) 180 K
E) 250 K

Question

Quizplus · Accepted Answer

Since the process is adiabatic and the gas expands into a vacuum (free expansion), there is no work done and no heat exchange, so the internal energy remains constant. For an ideal gas, this means the temperature remains the same. Thus, the final temperature is 250 K.

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