Acids and Bases - Calculating pH

Worked Chemistry Problems

pH is a measure of acidity.
pH is a measure of acidity.

pH is a measure of the acidity or alkalinity of a chemical solution. A solution with a pH less than 7 is considered to be acidic. One with a pH greater than 7 is alkaline. A pH equal to 7 is a neutral solution. Here is a simple example of how to calculate the pH of a solution when the hydrogen ion concentration is known:

Question

What is the pH of a solution with [H+] = 1 x 10-6 M.

Solution

pH is calculated by the formula

pH = - log [H+]

Substitute [H+] with the concentration in the question.

pH = - log (1 x 10-6)
pH = -(-6)
pH = 6

Answer

The pH of the solution is 6.