Assertion: The pressure of a fixed amount of an ideal gas is proportional to its temperature.
Reason: Frequency of collisions and their impact both increase in proportion of the square root of temperature.

Options

A. Statement-I is True, Statement-II is True and Statement-II is a correct explanation for Statement-I.
B. Statement-I is True, Statement-II is True and Statement-II is NOT a correct explanation for Statement-I.
C. Statement-I is True, Statement-II is False.
D. Statement-I is False, Statement-II is True.

Explanation

To solve the given assertion and reason question, we will follow a systematic approach:

### Step-by-Step Solution:

1. **Understanding the Assertion**:
- The assertion states that "The pressure of a fixed amount of an ideal gas is proportional to its temperature."
- According to the ideal gas law, \( PV = nRT \), where \( P \) is pressure, \( V \) is volume, \( n \) is the number of moles, \( R \) is the universal gas constant, and \( T \) is the temperature.
- For a fixed amount of gas (fixed \( n \)) and fixed volume \( V \), we can rearrange the equation to show that \( P \propto T \). Therefore, the assertion is **true**.

2. **Understanding the Reason**:
- The reason states that "Frequency of collisions and their impact both increase in proportion to the square root of temperature."
- From the kinetic theory of gases, we know that the root mean square speed (\( u_{rms} \)) of gas molecules is given by \( u_{rms} = \sqrt{\frac{3RT}{m}} \).
- The collision frequency is directly proportional to the root mean square speed, which means it is also proportional to the square root of temperature. Therefore, the reason is also **true**.

3. **Evaluating the Relationship**:
- While both the assertion and reason are true, we need to determine if the reason correctly explains the assertion.
- The assertion relates pressure and temperature directly, while the reason discusses collision frequency and its relation to temperature. These are related concepts, but the reason does not directly explain why pressure is proportional to temperature.
- Therefore, the reason is **not the correct explanation** for the assertion.

4. **Conclusion**:
- Both the assertion and reason are true, but the reason does not provide a correct explanation for the assertion.
- The correct answer is that both statements are true, but the reason is not the correct explanation for the assertion.

### Final Answer:
Both the assertion and reason are true, but the reason is not the correct explanation for the assertion.

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