posted by Sarah .
Calculate [H3O] an [OH] for a sodium hydroxide solution having a pH of 12.5.
I'm having a hard time with this i'm not sure how to start it. Please help me!
I would start by converting pH to pOH.
pH + pOH = pKw = 14
Then solve for OH^= from
pOH = -log(OH^-)
Or you can go another way.
pH = -log(H^+) and solve for (H^+), then
(H^+)(OH^-) = Kw = 1E-14 and solve for OH^-