A buffer solution is a solution that resists changes in pH when small amounts of acid or base are added to it. It consists of a weak acid and its conjugate base, or a weak base and its conjugate acid.
A substance that donates protons (H+) in a chemical reaction.
The species that remains after an acid has donated a proton.
A measure of the acidity or alkalinity of a solution, ranging from 0 to 14.