An acid is defined as a proton donor-the hydrogen ion (H+) dissociates from the acid in a solution. Hydrocholoric acid is a strong acid-all of the acid molecules will release their protons into a solution, making it very acidic. Ethanoic acid, on the other hand, is a weak acid-it will only donate some of its hydrogen ions into a solution, making it less acidic than hydrochloric acid solution.