Which of the following sets of conditions could exist when two liquids which are completely miscible in one another are mixed? A) ΔH_soln 0, entropy of system decreases B) ΔH_soln ≈ 0, entropy of system decreases C) ΔH_soln ≈ 0, entropy change of system ≈ 0 D) ΔH_soln ≈ 0, entropy of system increases E) None of these choices is correct.

Question

Which of the following sets of conditions could exist when two liquids which are completely miscible in one another are mixed? A) ΔH_soln > 0, entropy of system decreases B) ΔH_soln ≈ 0, entropy of system decreases C) ΔH_soln ≈ 0, entropy change of system ≈ 0 D) ΔH_soln ≈ 0, entropy of system increases E) None of these choices is correct.

Quizplus · Accepted Answer

When two liquids which are completely miscible in one another are mixed, the enthalpy of the system (ΔH) is usually close to zero because there are no significant intermolecular forces to be broken or formed during the mixing process. However, the entropy of the system (ΔS) increases because the molecules of the two liquids are able to move more freely throughout the solution than when they were separate. Therefore, the best choice is option D, where ΔH_soln is close to zero and the entropy of the system increases.

Which of the Following Sets of Conditions Could Exist When