Which of the following has pH value 7?

Correct answer: (e) None of the above/More than one of the above

Explanation

At 25 °C, pH 7 means neutral: [H⁺] = [OH⁻] = 10⁻⁷ mol/L. Pure water is neutral, and so is any neutral solution.

Basic solutions have pH above 7 and acidic solutions below 7. Since both (a) and (b) are correct, the answer is "More than one of the above".