What is pH defined as?

pH is defined as the negative logarithm to the base 10 of the hydrogen ion concentration in a solution. This definition is crucial in chemistry because it allows for a convenient way to express the acidity or alkalinity of a solution. The scale ranges from 0 to 14, where lower values indicate higher acidity (greater hydrogen ion concentration), and higher values indicate higher alkalinity (lower hydrogen ion concentration).

The logarithmic nature of the pH scale means that each whole number change in pH corresponds to a tenfold change in hydrogen ion concentration. For example, a solution with a pH of 3 is ten times more acidic than a solution with a pH of 4 due to the difference in hydrogen ion concentration.

Understanding the concept of pH is essential for various applications in chemistry, biology, environmental science, and medicine, as the pH of a solution can significantly affect chemical reactions and biological processes.