Acud Base PH, POH

Question

For a solution with a pH of 4, what would be the value of [H^+] , [OH^−] and pOH, respectively?

Answer 1

You should know/learn the following:

pH = -log [H⁺]

pOH = -log [OH-]

pH + pOH = 14

[H⁺][OH-] = 1x10^-14

With these relationships, you can solve all problems of this type.

pH = 4 means [H⁺] = 1x10^-4 (because -log 1x10^-4 = 4)

[OH-] = 1x10^-14/1x10^-4 = 1x10^-10 M = [OH-]

pOH = -log [OH-] = -log 1x10^-10 = 10 = pOH

You can also find pOH from pH + pOH = 14 and pOH = 14 - 4 = 10