Which term describes substances that can neutralize acids and bases in solution?

The term that describes substances capable of neutralizing acids and bases in solution is "buffer." Buffers are solutions that resist significant changes in pH when small amounts of an acid or a base are added. They consist of a weak acid and its conjugate base, or a weak base and its conjugate acid. This property makes buffers essential in various biological and chemical processes, including maintaining the pH balance in living organisms and laboratory settings.

A buffer works by either donating protons (H⁺ ions) when the solution becomes too basic or accepting protons when the solution becomes too acidic, thus stabilizing the pH. This characteristic is crucial in many applications, such as biochemistry, where enzyme activity can be affected by pH changes.

In contrast, the other terms listed do not possess this buffering capability. A solvent refers to the substance in which solutes are dissolved, typically a liquid; a solute is the substance that is dissolved in a solution; and a catalyst is a substance that increases the rate of a chemical reaction without being consumed in the process. None of these options have the specific capacity to manage pH levels in the manner that buffers do.