The vapour pressure of a solution having solid as solute and liquid as solvent is:

Options

A. Directly proportional to mole fraction of the solvent
B. Inversely proportional to mole fraction of the solvent
C. Directly proportional to mole fraction of the solute
D. None of these

Answer

To solve the question regarding the vapor pressure of a solution with a solid as solute and a liquid as solvent, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Components**:
- In this scenario, we have a solid solute (which is typically non-volatile) and a liquid solvent.

**Hint**: Remember that non-volatile solutes do not contribute to the vapor pressure of the solution.

2. **Applying Raoult's Law**:
- Raoult's Law states that the vapor pressure of the solvent in a solution is directly proportional to the mole fraction of the solvent in that solution.

**Hint**: Raoult's Law is crucial for understanding how the presence of a solute affects the vapor pressure of a solvent.

3. **Expressing Raoult's Law Mathematically**:
- The mathematical expression of Raoult's Law can be written as:
\[ P = X_{solvent} \cdot P^0_{solvent} \]
where \( P \) is the vapor pressure of the solution, \( X_{solvent} \) is the mole fraction of the solvent, and \( P^0_{solvent} \) is the vapor pressure of the pure solvent.

**Hint**: Pay attention to the terms in the equation; the mole fraction of the solvent plays a crucial role.

4. **Analyzing the Options**:
- Since the vapor pressure of the solution depends directly on the mole fraction of the solvent, we can conclude that the vapor pressure of the solution is directly proportional to the mole fraction of the solvent.

**Hint**: Look for options that mention the relationship between vapor pressure and mole fraction of the solvent.

5. **Conclusion**:
- Therefore, the correct answer to the question is that the vapor pressure of a solution having a solid as solute and a liquid as solvent is directly proportional to the mole fraction of the solvent.

**Hint**: Confirm that the answer aligns with the principles of Raoult's Law.

### Final Answer:
The vapor pressure of a solution having solid as solute and liquid as solvent is directly proportional to the mole fraction of the solvent in the solution.