A solution has a hydroxide ion concentration of 1 * 10^-¹¹ M.What is the pH of the solution,and is it acidic or basic?

Question

Quizplus · Accepted Answer

The pH of a solution can be calculated using the formula pH = -log[H+], where [H+] is the hydrogen ion concentration. Since this solution has a hydroxide ion concentration of 1x10^-11 M, we can use the equation Kw = [H+][OH-] = 1x10^-14 to find the hydrogen ion concentration. 
[H+] = Kw/[OH-] = 1x10^-14/1x10^-11 = 1x10^-3 M
pH = -log[H+] = -log(1x10^-3) = 3
A pH of 3 indicates an acidic solution. Therefore, the answer is C.

A Solution Has a Hydroxide Ion Concentration of 1