Acids and Bases What Is An Acid Or A Base? By the 1884 definition of Svante Arrhenius (Sweden), an acid is a material that can release a proton or hydrogen ion (H+ Here’s what I got. A generic weak acid "HA" will dissociate in aqueous solution according to the following equilibrium "HA"_ ((aq)) rightleftharpoons "H"_ ((aq. pH and pKa are ways to express the strength of acids. Use the Henderson-Hasselbalch…