What does the pH scale measure?

The pH scale is a logarithmic scale that measures the hydrogen ion concentration in a solution. Specifically, it quantifies how acidic or basic a solution is based on the concentration of hydrogen ions (H⁺) present. A lower pH value indicates a higher concentration of hydrogen ions, making the solution more acidic, while a higher pH value reflects a lower concentration of hydrogen ions, indicating a basic or alkaline solution.

This measurement is critical in various fields, including chemistry, biology, environmental science, and medicine, where the acidity or alkalinity of a solution can significantly affect reactions, biological functions, and environmental conditions. Understanding pH is vital for processes such as buffer solutions, enzymatic reactions, and analyzing the chemical behavior of substances in different environments.