What is the hydroxide ion concentration in a solution with [H3O+] = 7.67*10^-9 M?

To determine the hydroxide ion concentration in a solution, we can use the equation for the ion product of water (Kw) which is equal to the product of the concentrations of hydrogen ions (H3O+) and hydroxide ions (OH-) in water.

Kw = [H3O+][OH-]

In neutral water, the concentrations of H3O+ and OH- ions are equal, so we can say:

[H3O+] = [OH-]

Given that the concentration of H3O+ is 7.67*10^-9 M, we can substitute this value into the equation:

7.67*10^-9 M = [OH-]

Therefore, the hydroxide ion concentration in the solution is 7.67*10^-9 M.