Arrhenius and Armstrong: How Active Opponents in the History of Chemistry Became Major Contributors to Modern Electrolyte Chemistry

Abstract

In the late 19th and early 20th centuries Svante Arrhenius and Henry Armstrong understood the dissolution process of salts in water quite differently. Arrhenius saw the dissolution process as one whereby the salt partially dissociated into its ions and Armstrong saw the dissolution process as one whereby the salt associated itself with water. History is somewhat kinder to Arrhenius than it is to Armstrong in that Arrhenius won the Nobel Prize for Chemistry in 1903 for his electrolytic dissociation theory whereas Armstrong was considered of a 'hot air balloon' who made it his business to oppose every new thought in chemistry. In the 1920s Arrhenius' view of partial dissociation was replaced by a view of total dissociation for strong electrolytes with activity and osmotic coefficients being used to account for non-ideal solution behaviour. However, recent research has shown that strong 1:1 electrolytes are best understood by using Arrhenius' original idea of partial dissociation rather than total dissociation and Armstrong's idea of hydration. This strange confluence of factors has important implications for chemical epistemology and its role in chemistry education.