A solution has a hydrogen ion (or hydronium ion) concentration of 3.16×10−^8 M.
What is the pH of the solution?

a) 7.0

b) 7.5

c) 8.0

d) 8.5

The pH of the solution is 7.5

Explanation:

pH, short for Hydrogen Potential, is a parameter used to measure the degree of acidity or alkalinity of a substance.

PH is the measure of the activity of hydrogen ions in solutions and defined as the opposite of the base 10 logarithm or the negative logarithm of the activity of hydrogen ions.

pH= - log [H⁺]

The pH scale ranges from 0 to 14. Values less than 7 indicate the acidity range and those greater than 7 indicate alkalinity or basicity. Value 7 is considered neutral.

In this case, the concentration of the hydrogen ion is:

[H⁺]=3.16*10⁻⁸ M

Replacing in the definition of pH:

pH= - log (3.16*10⁻⁸)

pH= 7.50

The pH of the solution is 7.5