A thermally insulated container is divided into two equal compartments by a thin…
PHYSICS · Multi-part · A Level · Physics · Further mechanics and thermal physics · Further mechanics and thermal physics
Problem
A thermally insulated container is divided into two equal compartments by a thin removable partition. Initially, the left compartment contains 0.20mol of neon gas at 300 K, and the right compartment contains 0.10mol of helium gas at 600 K. Both gases are ideal and monatomic, and the volumes of the two compartments are the same. The partition is suddenly punctured, allowing the gases to mix and reach a common final temperature without exchanging energy with the surroundings or changing the total volume.
Constants: R=8.31Jmol−1K−1.
(a) Write an expression for the total internal energy of the system before the partition is punctured in terms of the given quantities.
(b) Calculate the final equilibrium temperature of the gas mixture after the partition is punctured.
(c) Determine the percentage change in the average translational kinetic energy of a helium atom as it goes from its initial state to the final equilibrium state.
(d) Explain whether the total internal energy of the gas mixture has changed during the mixing process, and justify your answer using energy-conservation considerations.