What term describes a substance that donates protons in a chemical reaction?

The term that describes a substance that donates protons in a chemical reaction is an acid. In the context of acid-base chemistry, acids are defined by their ability to release hydrogen ions (H⁺) or protons into a solution. This characteristic is essential in acid-base reactions, contributing to the formation of different chemical species and the overall balance of the reaction. Acids can be classified further into strong and weak acids, depending on their ability to dissociate completely or partially in water.

In contrast, a base is characterized by its ability to accept protons or donate hydroxide ions (OH⁻) in a reaction. The concept of neutrality refers to substances that are neither acidic nor basic, often represented by a pH level of 7, while a solvent is a medium in which substances (solutes) are dissolved to form a solution. Understanding these distinct definitions highlights why the correct choice is specifically associated with a substance that donates protons, which aligns with the definition of an acid.