An Arrhenius acid is a substance that when added to water increases the concentration of H1+ ions. An Arrhenius base is is a substance that when added to water increases the concentration of OH1- ions. A Bronsted acid is a substance that can donate a hydrogen ion. A Bronsted base is a substance that can accept a hydrogen ion. A Lewis acid accepts lone pair electrons. A Lew base donates lone pair electrons. Solution An Arrhenius acid is a substance that when added to water increases the concentration of H1+ ions. An Arrhenius base is is a substance that when added to water increases the concentration of OH1- ions. A Bronsted acid is a substance that can donate a hydrogen ion. A Bronsted base is a substance that can accept a hydrogen ion. A Lewis acid accepts lone pair electrons. A Lew base donates lone pair electrons..