An ideal gas is allowed to undergo a free expansion. If its initial volume is V₁ and its final volume is V₂, the change in entropy is A) nR ln (V₂/V₁) B) nRT ln (V₂/V₁) C) nk ln (V₂/V₁) D) 0 E) nR V₂/V₁

Question

Quizplus · Accepted Answer

During a free expansion, the gas expands without performing any work on the surroundings and there is no heat exchange between the gas and surroundings. As a result, the process is adiabatic and reversible, and the change in entropy is given by ΔS = nR ln (Vf/Vi), where n is the number of moles of the gas, R is the gas constant, Vf is the final volume, and Vi is the initial volume. Therefore, the correct choice is A.

An Ideal Gas Is Allowed to Undergo a Free Expansion