Assertion: One molar aqueous solution is more concentrated than that of 1 molal aqueous solution .
Reason : Molarity is a function of temperature as volume depends on temperature.

Options

A. If both assertion and reason are true and reason is the correct explanation of assertion
B. If both assertion and reason are true but reason is not the correct explanation of assertion.
C. If assertion is true but reason is false
D. If both assertion and reason are false

Explanation

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

**Assertion:** One molar aqueous solution is more concentrated than that of one molal aqueous solution.

**Reason:** Molarity is a function of temperature as volume depends on temperature.

### Step-by-Step Solution:

1. **Understanding Molarity and Molality:**
- Molarity (M) is defined as the number of moles of solute per liter of solution.
- Molality (m) is defined as the number of moles of solute per kilogram of solvent.

2. **Comparing Molarity and Molality:**
- For a 1 molal solution, we have 1 mole of solute dissolved in 1 kg of solvent (water).
- For a 1 molar solution, we have 1 mole of solute dissolved in enough water to make the total volume of the solution 1 liter.

3. **Density of Water:**
- The density of water is approximately 1 g/cm³, which means 1 kg of water occupies about 1 liter of volume.
- However, when we dissolve a solute in water, the total volume of the solution may be less than 1 liter due to the solute's volume.

4. **Volume Considerations:**
- In a 1 molal solution, we have 1 kg of water (1 liter) plus the volume of the solute.
- In a 1 molar solution, the volume is fixed at 1 liter, which includes both the solute and the solvent.

5. **Concentration Comparison:**
- Since the 1 molal solution has 1 mole of solute in 1 kg of solvent, and the 1 molar solution has 1 mole of solute in a volume that may be less than 1 liter, the concentration of the 1 molal solution is generally higher than that of the 1 molar solution.
- Therefore, the assertion is incorrect.

6. **Analyzing the Reason:**
- The reason states that molarity is a function of temperature because volume depends on temperature.
- This statement is correct since the volume of a solution can change with temperature, affecting the molarity.

7. **Conclusion:**
- The assertion is false, but the reason is true. Therefore, the correct answer is that the assertion is incorrect, while the reason is correct.

### Final Answer:
The assertion is false, and the reason is true.