Assertion (A) Molarity of a solution in liquid state changes with temperature.
Reason (R ) The volume of a solution charges with change in temperature.

Options

A. Assertion and reason both are correct statements and reason is correcft explanation for assertion.
B. Assertion and reason both are correct statements but reason is not correct explanation for assertion.
C. Assertion is correct statement but reason is wrong statement.
D. Assertion and reason both are incorrect statements.

Explanation

To solve the question, we need to analyze the assertion and reason provided:

**Assertion (A)**: Molarity of a solution in liquid state changes with temperature.
**Reason (R)**: The volume of a solution changes with change in temperature.

### Step-by-Step Solution:

1. **Understanding Molarity**:
- Molarity (M) is defined as the number of moles of solute per liter of solution.
- Mathematically, Molarity = \( \frac{\text{Number of moles of solute}}{\text{Volume of solution in liters}} \).

2. **Effect of Temperature on Volume**:
- When the temperature of a solution changes, the volume of the solution can also change due to thermal expansion or contraction.
- Generally, liquids expand when heated and contract when cooled, which affects their volume.

3. **Impact on Molarity**:
- Since molarity depends on the volume of the solution, any change in volume due to temperature will directly affect the molarity.
- For example, if the volume increases with temperature, the molarity will decrease (assuming the number of moles of solute remains constant), and vice versa.

4. **Evaluating the Assertion and Reason**:
- The assertion is correct: Molarity does change with temperature.
- The reason is also correct: The volume of the solution changes with temperature, which is the reason why molarity changes.

5. **Conclusion**:
- Both the assertion and the reason are correct, and the reason correctly explains the assertion.

### Final Answer:
Both the assertion and the reason are correct, and the reason is the correct explanation for the assertion.