Assertion (A): `pH` of neutral solution is always `7`.
Reason (R) : `pH` of solution does not depend upon temperature.

Options

A. If both (A) and (R) are correc, and (R) is the correct explanation of (A).
B. If both (A) and (R) are correct but (R) is not the correct explanation of (A).
C. If (A) is correct, but (R) is incorrect.
D. If both (A) and (R) are incorrect.

Explanation

To solve the assertion-reason question, we need to analyze both the assertion and the reason provided.

### Step 1: Analyze the Assertion
The assertion states that the pH of a neutral solution is always 7.

- At 25°C, the pH of a neutral solution is indeed 7 because the concentrations of hydrogen ions \([H^+]\) and hydroxide ions \([OH^-]\) are equal, both being \(1 \times 10^{-7} \, \text{M}\).
- However, the pH of a neutral solution can change with temperature. As temperature increases, the ionization of water increases, leading to higher concentrations of both \([H^+]\) and \([OH^-]\), which can result in a pH that is less than 7.

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