Question

2 moles of oxygen are mixed adiabatically with another 2 moles of oxygen in a mixing chamber, so that the final total pressure and temperature of the mixture become the same as those of the individual constituents at their initial states. The universal gas constant is R. The change in entropy due to mixing, per mole of oxygen, is given by

Accepted Answer

The correct answer is (B) 0. Since the two gas samples are identical (same substance, same initial P and T) and the final P,T match the initial individual states, there is no genuine mixing effect to distinguish — this is the classical Gibbs-paradox case where mixing identical gases at unchanged P,T produces zero entropy change.

Explanation