How is the pH of a neutral solution at 25°C characterized?

In pure water at 25°C, the concentration of hydrogen ions (H⁺) and hydroxide ions (OH⁻) is equal, each being 1.0 × 10⁻⁷ M. The pH scale is based on the concentration of H⁺ ions, calculated using the formula pH = -log[H⁺]. For a neutral solution, where [H⁺] = 1.0 × 10⁻⁷ M, the pH is calculated as follows:

pH = -log(1.0 × 10⁻⁷) = 7.

This value characterizes a neutral solution, indicating that it is neither acidic nor basic. At 25°C, the pH of a neutral solution is consistently defined as exactly 7.

When considering other options, a pH below 7 indicates an acidic solution due to a higher concentration of H⁺ ions, while a pH above 7 suggests a basic solution with a lower concentration of H⁺ ions relative to OH⁻ ions. The concentration of solute can affect the pH, but in the context of pure water at 25°C, a neutral solution remains regulated to a p