Which of the following is correct for a solution showing positive deviations from Raoult's law?

Options

A. `DeltaV=+ve,DeltaH=+ve`
B. `DeltaV=-ve,DeltaH=-ve`
C. `DeltaV=+ve,DeltaH=-ve`
D. `DeltaV=-ve,DeltaH=+ve`

Explanation

To solve the question regarding the characteristics of a solution showing positive deviations from Raoult's law, we can break down the information provided in the video transcript into a step-by-step text solution.

### Step-by-Step Solution:

1. **Understanding Raoult's Law**:
- Raoult's law states that the vapor pressure of a solution is directly proportional to the mole fraction of the solvent in the solution. For ideal solutions, the interactions between different components are similar to those in the pure components.

2. **Defining Positive Deviation**:
- A solution exhibits positive deviation from Raoult's law when the vapor pressure of the solution is higher than what Raoult's law predicts. This occurs when the interactions between the different components (A and B) are weaker than the interactions between the same components (A-A and B-B).

3. **Interaction Analysis**:
- In a solution showing positive deviation, the interaction energy between A and B (A-B) is less than the interaction energy between A-A and B-B. This leads to an increase in vapor pressure.

4. **Thermodynamic Changes**:
- Positive deviation is associated with endothermic dissolution, meaning that the process absorbs heat. Therefore, the change in enthalpy (ΔH) is greater than zero (ΔH > 0).

5. **Volume Change**:
- When a solution shows positive deviation, the change in volume (ΔV) upon mixing is also positive (ΔV > 0). This indicates that the final volume after mixing is greater than the initial volume.

6. **Conclusion**:
- Therefore, for a solution showing positive deviations from Raoult's law, both ΔH and ΔV are positive. The correct option that reflects this is:
- **ΔH > 0 and ΔV > 0** (Option A).