What does pH measure?

pH is a measure of the concentration of hydrogen ions in a solution. It is a logarithmic scale that reflects how acidic or basic a solution is, with lower pH values indicating higher acidity (more hydrogen ions) and higher pH values indicating increased basicity (fewer hydrogen ions). The pH scale typically ranges from 0 to 14, where a pH of 7 is considered neutral.

Understanding pH is vital in water treatment and management because the acidity or basicity of water influences various chemical and biological processes, including the solubility of metals, disinfectant efficacy, and the health of aquatic life. Monitoring and managing pH is essential in maintaining water quality standards and ensuring the safety of drinking water.

The other options measure different ions that are not directly related to the concept of pH; thus, they do not define pH accurately.