[H3O+]=8×10−6M Express your answer using one decimal place.

Answer 1

What are you looking for? Are you supposed to find the pH? If so, it's the negative log of [H₃O⁺]

pH = -log 8x10^-6 = 5.10

If you are trying to find [OH-] it is

[OH-] = 1x10^-14 / 8x10^-6 = 1.25x10^-9 M