Suggestion of a Viewpoint Change for the Classification Criteria of Redox Reactions

Abstract

The four representative models that define oxidation–reduction reactions are often used differently in different situations or contexts in chemistry textbooks. Although integrated models have been suggested to overcome the confusion caused by this, they have not been successful. We therefore aim to interpret the causes for difficulties in the attempted integration of the various epistemological perspectives. The four key models, namely, the oxygen, hydrogen, electron, and oxidation state (or number) models, focus on the movement of matter. We, however, suggest the use of the Goodstein method, where the relative changes in the electronegativity orders in redox reactions should be employed rather than the properties of the reactants or products themselves. This requires a change of viewpoint from matter to process. We also suggest that the confusion of classifying redox reactions may occur from the viewpoint of matter. Therefore, new interpretations of redox reactions based on the relationship between reactants and products are suggested, considering the process viewpoint as a valuable criterion. While many researchers have tried to solve this problem by suggesting new models to classify redox reactions, we instead suggest a novel interpretation of the various redox models.

An Analysis of the Visual Representation of Redox Reactions in Secondary Chemistry Textbooks from Different Chinese Communities

“…Redox reactions provide fundamental knowledge for later learning in chemistry, for example, advanced electrochemistry or organic chemistry, and other subjects such as biology [8]. Redox reactions are, however, widely perceived as being difficult to comprehend both for secondary school pupils and university students [11][12][13][14] as well as being difficult to teach [15].…”

Introducing a Simple Equation To Express Oxidation States as an Alternative to Using Rules Associated with Words Alone

“…Rules for oxidation state calculation, as proposed by Goodstein, are simple and general. The same or similar rules are also recommended by Paik et al and Generalić, especially for calculation of oxidation numbers of atoms in organic molecules. According to Goodstein, the bonds formed by a given atom may be divided into three categories: bonds with more electronegative atoms, bonds with equally electronegative atoms, and bonds with less electronegative atoms.…”

“…Oxidation and reduction reactions are important topics in chemistry teaching, both from a theoretical and practical point of view. − Calculation of the oxidation states (oxidation numbers) of particular atoms in a molecule is a crucial step in processing and understanding redox reactions, especially in the case of organic compounds. Functional groups of organic compounds are classified, e.g., according to oxidation state of carbon atoms included in these groups .…”

“…This issue is usually explained in handbooks − and on Web sites , using sets of rules associated with words alone. The most recent overwiew of rules applied is provided in the article of Paik et al and references cited therein. The exploded structure method (ESM)/Lewis structure method of oxidation state calculation is an exception.…”

“…This method has been first described by Kauffman using rules associated by words alone. Jurowski and co-workers have expressed these rules using the equation As discussed by Paik et al, rules associated with words alone are difficult to remember, and there are also difficulties in their implementation in computer programs calculating oxidation states (such as an Oxidation Number Calculator).…”