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: Recall properties of ideal solutions.
For an ideal solution: - Enthalpy of mixing, \( \Delta H_{mixing} = 0 \)
- Volume of mixing, \( \Delta V_{mixing} = 0 \)
- Raoult's law is obeyed.

Step 2: Entropy consideration.
Entropy of mixing, \( \Delta S_{mixing} \), is not zero because mixing always leads to an increase in disorder.

Step 3: Conclusion.
Therefore, the correct answer is (C) \( \Delta S_{mixing} = 0 \), which is not satisfied by an ideal solution.