A solution contains a concentration of [H+] = 1.0 x 10-9 moles/L.
and a concentration of [OH ] = 1.0 x 10-5 moles/L. This solution is

a. acidic b. basic c. neutral d. none of the above.

The pH is the negative logarithm of the hydrogen ion concentration. Calculate the pH of the solutions.

Since it's been found that

This is the same as saying that pH + pOH = 14. The point where pH = 7 and pOH = 7 is called "neutral" because the concentration of hydrogen ions (acids) and hydroxide ions (bases) is equal. This means that if the pH is less than 7, the solution is acidic. If the pH is greater than 7, the solution is basic. If the pH is exactly 7, the solution is neutral.

Calculate the pH (or pOH) and you'll have your answer.