Question

Two statements are given below Statement I: Liquid A and liquid B form a non-ideal solution with positive deviation. \hspace{0.5cm} The interactions between A and B are weaker than A–A and B–B interactions. Statement II: For an ideal solution, \(\Delta_{\text{mix}} H = 2 \text{ kJ mol}^{-1} \); \(\Delta_{\text{mix}} V = 0\).

• A. Both statement I and II are correct
• B. Both statement I and II are not correct
• C. Statement I is correct but statement II is not correct
• D. Statement I is incorrect but statement II is correct

Hint:

- Non-ideal solutions with positive deviation occur when solute-solvent interactions are weaker than solute-solute or solvent-solvent interactions.
- For an ideal solution, the enthalpy of mixing is zero.

Answer 1

The Correct Option is C

Step 1: Understanding Statement I
- A non-ideal solution with positive deviation means that the interactions between A and B are weaker than A–A and B–B interactions.
- This results in higher vapor pressure and an increase in enthalpy when mixing occurs.
- Since this definition aligns with statement I, Statement I is correct. Step 2: Evaluating Statement II
- For an ideal solution, \(\Delta_{\text{mix}} H = 0\) and \(\Delta_{\text{mix}} V = 0\).
- The given statement claims \(\Delta_{\text{mix}} H = 2 \text{ kJ mol}^{-1}\), which is incorrect.
- Hence, Statement II is incorrect. Step 3: Conclusion
- Statement I is correct.
- Statement II is incorrect.
- Therefore, the correct answer is Option (3).