Question

Which of the following conditions is not satisfied by an ideal solution?

• A. \( \Delta H_{mixing} = 0 \)
• B. \( \Delta V_{mixing} = 0 \)
• C. \( \Delta S_{mixing} = 0 \)
• D. Raoult's Law is obeyed

Hint:

In an ideal solution, enthalpy and volume changes are zero, but entropy change is always positive due to increased randomness.

Answer 1

The Correct Option is C

Step 1: Ideal Solution Properties. For an ideal solution: \( \Delta H_{mixing} = 0 \), \( \Delta V_{mixing} = 0 \), and Raoult's law holds.

Step 2: Entropy of Mixing. The entropy of mixing, \( \Delta S_{mixing} \), is non-zero, as mixing inherently increases disorder.

Step 3: Final Deduction. Consequently, the correct choice is (C) \( \Delta S_{mixing} = 0 \), which is not a characteristic of ideal solutions.