# A solution with a pH of 7 has a [OH1-] of?

0M or 7M???????????????????

## Neither.

pH + pOH = pKw = 14.

You know pH and pKw, solve for pOH.

Then pOH = -log(OH^-). Solve for OH^-

You can do this another way and get the same answer.

pH = -log(H^+). Substitute pH and solve for (H^+), then

(H^+)(OH^-) = Kw = 1E-14. You know H^+) and Kw, solve for OH^-