The correct statement out of the following is :

Options

A. The boiling point of the solution falls on increasing the amount of solute
B. The boiling point of solution increases on diluting the solution
C. The freezing point of the solution is raised on adding more of solute
D. The freezing point of the solution decreases on increasing the amount of solute.

Answer

To solve the question, we need to analyze each of the provided statements regarding the behavior of solutions when solutes are added. Let's break it down step by step:

### Step 1: Analyze the First Statement
**Statement:** The boiling point of the solution falls on increasing the amount of solute.

- **Explanation:** The boiling point elevation is given by the formula:
\[ \Delta T_b = K_b \cdot m \]
where \( \Delta T_b \) is the elevation in boiling point, \( K_b \) is the ebullioscopic constant, and \( m \) is the molality of the solution.
- When we increase the amount of solute, the molality \( m \) increases, which leads to an increase in \( \Delta T_b \).
- Therefore, the boiling point of the solution increases, not falls.
- **Conclusion:** This statement is **false**.

### Step 2: Analyze the Second Statement
**Statement:** The boiling point of the solution increases on diluting the solution.

- **Explanation:** Diluting a solution means decreasing the concentration of solute, which in turn decreases the molality \( m \).
- Since \( \Delta T_b = K_b \cdot m \), a decrease in \( m \) results in a decrease in \( \Delta T_b \).
- Thus, the boiling point of the solution will decrease, not increase.
- **Conclusion:** This statement is **false**.

### Step 3: Analyze the Third Statement
**Statement:** The freezing point of the solution is raised on adding more solute.

- **Explanation:** The depression in freezing point is given by:
\[ \Delta T_f = K_f \cdot m \]
where \( \Delta T_f \) is the depression in freezing point, and \( K_f \) is the cryoscopic constant.
- Adding more solute increases the molality \( m \), which increases \( \Delta T_f \).
- Therefore, the freezing point of the solution decreases, not raises.
- **Conclusion:** This statement is **false**.

### Step 4: Analyze the Fourth Statement
**Statement:** The freezing point of the solution decreases on increasing the amount of solute.

- **Explanation:** As established, increasing the amount of solute increases the molality \( m \), which increases the depression in freezing point \( \Delta T_f \).
- Thus, the freezing point of the solution decreases as more solute is added.
- **Conclusion:** This statement is **true**.

### Final Answer
The correct statement is: **The freezing point of the solution decreases on increasing the amount of solute.**

---