Final answer:
The concentration of hydroxide ions in the aqueous solution is 1.0 × 10^-9 M.
Step-by-step explanation:
The hydroxide ion concentration can be determined using the equation [H3O+] × [OH-] = 1.0 × 10^-14. Since the concentration of the hydronium ion ([H3O+]) is given as 1.0 × 10^-5 M, we can rearrange the equation to solve for the hydroxide ion concentration ([OH-]).
Therefore, [OH-] = 1.0 × 10^-14 / [H3O+] = 1.0 × 10^-14 / 1.0 × 10^-5 = 1.0 × 10^-9 M
So, the concentration of hydroxide ions in the aqueous solution is 1.0 × 10^-9 M.