What does pH measure in a solution?

The concept of pH is central to understanding the acidity or basicity of a solution. Specifically, pH quantifies the concentration of hydrogen ions (H⁺) present in a solution. This measurement is fundamental because it allows chemists and scientists to determine how acidic or basic (alkaline) a solution is based on its H⁺ concentration.

A low pH value indicates a higher concentration of hydrogen ions, which signifies that the solution is more acidic. Conversely, a high pH value reflects a lower concentration of hydrogen ions, indicating that the solution is more basic. The pH scale is logarithmic, meaning that each whole number change on the scale represents a tenfold change in H⁺ concentration.

This relationship between pH and H⁺ concentration is critical in various chemical and biological processes, making it essential to accurately gauge the pH for applications ranging from industrial processes to biological systems.