How does the pH scale indicate acidity, neutrality, and alkalinity?

The pH scale is a logarithmic scale used to measure the acidity or alkalinity of a solution, with values typically ranging from 0 to 14. A pH value below 7 indicates an acidic solution, a pH of 7 indicates a neutral solution, and a pH above 7 indicates an alkaline (or basic) solution. This established range is due to the concentration of hydrogen ions (H⁺) in a solution.

When the pH drops below 7, it signifies an increase in hydrogen ion concentration, which corresponds to acidity. Conversely, when the pH is above 7, there is a decrease in hydrogen ion concentration and an increase in hydroxide ions (OH⁻), which indicates alkalinity. This classification is foundational in chemistry and is widely accepted and used in various scientific fields.