Calculate the hydroxide ion concentration, [OH-], for a solution with a pH of 7.07.

Question

Calculate the hydroxide ion concentration, [OH^-], for a solution with a pH of 7.07.

[OH^-] = ?M

Answer 1

Here are 2 different ways to get the answer:

pH + pOH = 14

pOH = 14 - 7.07

pOH = 6.93

[OH-] = 1x10^-6.93 = 1.17x10^-7 M

pH = -log [H+]

[H+] = 1x10^-7.07 = 8.51x10^-8 M

[H+][OH-] = 1x10^-14

[OH-] = 1x10^-14 / 8.5x10^-8

[OH-] = 1.17x10^-7 M