There are inherent difficulties in a subject like chemistry particularly the notion of a chemical reaction. In this paper the difficulties are discussed from a teaching and learning perspective and from a history of chemistry perspective. Three teaching/learning studies of the incompleteness of the iron thiocyanate reaction in chemical equilibrium are reviewed and it is shown that a recent historical study of the iron thiocyanate reaction has the potential to challenge the interpretation of the incompleteness of the reaction. This establishes (...) a controversial context where students can be introduced to epistemic thinking, that is, how to interrogate chemistry data and form a conclusion which resonates with what we know about the nature of science. A curriculum suggestion for pre-service chemistry teachers is provided. (shrink)

This Brief presents an historical investigation into the reaction between ferric ions and thiocyanate ions, which has been viewed in different ways throughout the last two centuries. Historically, the reaction was used in chemical analysis and to highlight the nature of chemical reactions, the laws of chemistry, models and theories of chemistry, chemical nomenclature, mathematics and data analysis, and instrumentation, which are important ingredients of what one might call the nature of chemistry. Using the history of the iron thiocyanate reaction (...) as a basis, the book’s main objective is to explore how chemistry develops its own knowledge base; how it assesses the reliability of that base; and how some important tools of the trade have been brought to bear on a chemical reaction to achieve understanding, a worthwhile goal of any historical investigation. (shrink)

Mathematics is so common-place in modern physics and chemistry that one may not realise how controversial its admittance was to these fields in the eightieth and ninetieth centuries respectively. This paper deals with the controversy during the formation of physical chemistry as a discipline in the late ninetieth and early twentieth centuries and sketches more recent criticisms of the way mathematics has been used in solution chemistry. The controversy initially related particularly to electrolyte chemistry and its emerging use of mathematics (...) to support Arrhenius’ theory of ionic dissociation. The impact of mathematics on the field is divided into three phases: that from 1880 to 1920 which was a period of heightened controversy; that from 1920 to 1990 which was a period of relative calm and mathematical development; and finally, that from 1990 to the present which has been a time of reflective criticism of the extensive use of empirical parameters in the emergent mathematics of the twentieth century. It is argued that the current solution to the criticism, as proposed by Heyrovska, is best viewed in the light of the historical development of the controversy. (shrink)

A review of the chemical education research literature suggests that the term constructivism is used in two ways: experience-based constructivism and discipline-based constructivism. These two perspectives are examined as an epistemology in relation to the teaching and learning of the concept of idealization in chemistry. It is claimed that experience-based constructivism is powerless to inform the origin of such concepts in chemistry and while discipline-based constructivism can admit such theoretical concepts as idealization it does not offer any unique perspectives that (...) cannot be obtained from other models. Chemical education researchers do not consistently appeal to constructivism as an epistemology or as a teaching/learning perspective and it is shown that, while it draws attention to worthwhile teaching/learning strategies, it cannot be considered as foundational to chemical education research and tends to be used more as an educational label than as an undergirding theory. (shrink)