Question
For an aqueous solution at 25°C, pH + pOH is
- 10
- 7
- 12
- 14
Answer
14
Explanation
For an aqueous solution at 25°C, pH + pOH = 14. This is because pH is defined as -log[H+] and pOH is defined as -log[OH–], and the product of [H+] and [OH–] in water is always 10-14 at 25°C. Therefore, pH + pOH = -log[H+] + (-log[OH–]) = -log([H+][OH–]) = -log(10-14) = 14.