Question

could you tell me if these are right and help me with the other 2 I cant seem to get them to come out.

Calculate the pH of each solution given the following [H3O+] or [OH -] values.
(a) [H3O+] = 1.5 10-8 M
1.0E-7 is what I got

(b) [H3O+] = 5.3 10-6 M

(c) [OH -] = 4.8 10-2 M
I get 7.0

(d) [OH -] = 9.0 10-3 M



Thank you.

Answer 1

Perhaps you have misread the question. For the first one,
(H3O^+) = 1.5E-8
pH = -log(H^+)
pH = -log(1.5E-8)
pH = -(-7.82)
pH = 7.82.