What happens to the pH of a solution as the concentration of H+ ions increases?

As the concentration of H+ ions in a solution increases, the pH value of that solution decreases. This relationship stems from the definition of pH, which is calculated as the negative logarithm (base 10) of the hydrogen ion concentration. Mathematically, pH = -log[H+].

When the concentration of H+ ions rises, the logarithmic function indicates that a higher concentration will correspond to a lower pH value. For example, a solution with a high concentration of H+ ions is acidic and has a low pH, such as a pH of 1, while a solution with fewer H+ ions would have a higher pH, such as 7 (neutral) or even higher (basic).

Therefore, as more H+ ions are added to the solution, the pH decreases, demonstrating the inverse relationship between hydrogen ion concentration and pH. This fundamental principle is crucial in understanding acid-base chemistry and is applied extensively in many chemical and biological processes.