What does pH measure in a solution?

pH is a scale that measures the acidity or alkalinity of a solution, specifically focusing on the concentration of hydrogen ions (H+) present in that solution. The pH scale typically ranges from 0 to 14, with lower values indicating a higher concentration of hydrogen ions, which corresponds to acidic solutions, and higher values indicating a lower concentration of hydrogen ions, which corresponds to basic (alkaline) solutions. A neutral pH of around 7 indicates equal concentrations of hydrogen ions and hydroxide ions.

This understanding of pH is crucial in various scientific fields, including environmental science and biology, because the acidity or alkalinity of water can greatly affect the health of aquatic ecosystems, influencing the solubility and availability of nutrients, metals, and other compounds. Knowing how to interpret pH levels helps in assessing water quality and making informed decisions about environmental management.