Calculate the pH of the following solutions.

Question

(A) 0.95 NaOH
(B) 9.9x10^-10 M NaOH
(C) 6.7 M NaOH

Answer 1

a and c are done the following.
NaOH is a strong base which means OH^- = (NaOH).
Then pOH = -log(OH^-) and
pH + pOH = pKw = 14

For b, note that (NaOH) is very small and you need to take OH^- from H2O into account.