What are solutions that can tolerate the addition of strong acid or base with only slight pH changes called?

Buffered solutions are specifically designed to resist changes in pH when small amounts of strong acids or bases are added. They achieve this stability through the presence of a weak acid and its conjugate base (or a weak base and its conjugate acid) in equilibrium, which can react with added hydrogen ions (H⁺) or hydroxide ions (OH⁻). This buffering action helps maintain a relatively constant pH in biological and chemical systems, which is crucial for processes that are sensitive to pH fluctuations.

In contrast, concentration solutions merely refer to solutions with a certain amount of solute per unit volume of solvent and do not imply any ability to buffer pH changes. Aqueous solutions refer to solutions where the solvent is water, without any specific mention of their ability to resist pH changes. Catalytic solutions involve substances that speed up chemical reactions without being consumed in the process, which does not relate to pH stability. Therefore, buffered solutions are the correct term for those that can tolerate the addition of acids or bases with only slight changes in pH.