What is the pH of a solution with a hydrogen ion concentration of 1 x 10^-8 moles per liter?

To determine the pH of a solution based on its hydrogen ion concentration, you can use the formula for pH, which is defined as the negative logarithm (base 10) of the hydrogen ion concentration. The formula is:

pH = -log[H⁺]

In this case, the hydrogen ion concentration is given as 1 x 10^-8 moles per liter. Substituting this value into the formula:

pH = -log(1 x 10^-8)

Calculating this gives:

pH = -(-8) = 8

This result indicates that the solution is slightly basic, which corresponds to a pH of 8. A pH of 7 is considered neutral, with values below indicating acidity and values above indicating basicity. Therefore, a pH of 8 signifies that the solution has a lower concentration of hydrogen ions compared to neutral water, thus making it basic.

Understanding that a pH of 8 corresponds directly to the given hydrogen ion concentration clarifies that option D is indeed the correct answer.