Which term describes a property that resists pH changes in a solution?

The term that describes a property that resists pH changes in a solution is buffering capacity. A buffer is a system that can maintain a relatively constant pH when small amounts of acids or bases are added. This is achieved through the presence of weak acids and their conjugate bases (or vice versa) in the solution, which can react with added protons (H⁺ ions) or hydroxide ions (OH⁻ ions) to minimize shifts in pH.

In biological and chemical systems, maintaining a stable pH is crucial because even minor fluctuations can have significant effects on chemical reactivity and biological processes. Buffers are used widely in laboratory settings, biological systems, and industrial processes to ensure stability in various applications, such as enzyme activity and metabolic reactions.

Other terms provided do not specifically refer to the resistance to pH changes. Acidity refers to the concentration of hydrogen ions in a solution, while basicity relates to the concentration of hydroxide ions. Hydration relates to the process of water molecules surrounding solute ions or molecules, which is not directly related to pH stability. Thus, buffering capacity is the most accurate description of the property in question.