Question

Which expression represents the concentration of OH– ions in solution? a. [OH–]  10–14 b. 10–14  [H3O+] c. 10–14  [H3O+] d. 10–14 – [H3O+]

Answer 1

10^-14 / [H3O+]

Step-by-step explanation:

Hydronium (H3O+) and hydroxide ions (OH-) are both present in pure water and in all aqueous solutions.

Their respective concentrations in water are 10^-7 M each and are inversely proportional to each other as given by the ion product of water, Kw.

Kw = [H3O+][OH−]

Where Kw = 1.0 * 10^-14,

[H3O+] = concentration of hydronium ions

[OH-] = concentration of hydroxide ions

Therefore, [OH-] = Kw / [H3O+]

[OH-] = 10^-14/[H3O+]