Answer:
11.
Explanation:
[OH⁻] = 0.001 M.
∵ pOH = - log[OH⁻]
∴ pOH = - log(0.001 M) = 3.
∵ pH + pOH = 14.
∴ pH = 14 - pOH = 14 - 3 = 11.