A solution has a pOH of 8.20. What is the concentration of H3O+?

Answer 1

Recall that pH + pOH = 14

pH = 14 - pOH = 14 - 8.20

pH = 5.80

Since pH = -log [H3O⁺], then [H3O⁺] = 1x10^-5.80

Written another way, [H3O+] = 1.58x10^-6 M

Done another way:

pOH = 8.20

[OH-] = 1x10^-8.20

[OH-] = 6.31x10^-9 M

[H3O⁺][OH-] = 1x10^-14

[H3O⁺] = 1x10^-14/6.31x10^-9

[H3O^+] = 1.58x10^{-6 M}