Answer:
12. [OH-] = 3.53 x 10^-10
[H+] = 2.82 x 10^-5
13. [OH-] = 1.1 x 10^-11
14. [H+] = 4.2 x 10^-6
Explanation:
12. [OH-] = 10^-9.45 = 3.53 x 10^-10
[H+] = 10^(9.45-14) = 2.82 x 10^-5
13. [OH-] = Kw/ (8.7 x 10^-4) = 1.1 x 10^-11
14. [H+] = Kw/ (2.4 x 10^-9) = 4.2 x 10^-6