Question

A solution at 25°C is 1.0 x 10^-5 M H3O+. What is the concentration of OH- in this solution

Answer 1

Answer:
1.0 × 10–9 M OH–

Explanation:
pH = -Log[H+]
pOH = -Log[OH-]
But;
pH + pOH = 14
Therefore;
[H+] + [OH-] = 1.0 × 10^-14 M
Therefore;
[OH-] = 1.0 × 10^-14 M - (1.0 × 10^–5 M)
= 1.0 × 10^-9 M OH–