H-atom and O-atom methods: from balancing redox reactions to determining the number of transferred electrons

Abstract

Defining and balancing redox reaction requires both chemical knowledge and mathematical skills. The prevalent approach is to use the concept of oxidation number to determine the number of transferred electrons. However, the task of calculating oxidation numbers is often challenging. In this article, the H-atom method and O-atom method are developed for balancing redox equations. These two methods are based on the definition of redox reaction, which is the gain and loss of hydrogen or oxygen atoms. They complement current practices and provide an alternate path to balance redox equations. The advantage of these methods is that calculation of oxidation number is not required. Atoms are balanced instead. By following standard operating procedures, H-atom, O-atom, and H2O molecule act as artificial devices to balance both inorganic and organic equations in molecular forms. By using the H-atom and O-atom methods, the number of transferred electrons can be determined by the number of transferred H-atoms or O-atoms, which are demonstrated as electron-counting concepts for balancing redox reactions. In addition, the relationships among the number of transferred H-atom, the number of transferred O-atom, the number of transferred electrons, and the change of oxidation numbers are established.

Investigating the mangle of teaching oxidation–reduction with the VisChem approach: problematising symbolic traditions that undermine chemistry concept development

“…Furthermore, both secondary and tertiary chemistry educators must not become complacent if using any reaction description that is solely symbolic. The predilection to rely on symbolic heuristics has alarmingly gone uncontested insofar that particulatelevel mechanism and causality are no longer salient redox learning outcomes (Mui and Tully, 2022;Yuen and Lau, 2022). Particulate-level phenomena cannot be substituted with chemistry symbols if the goal were to promote chemistry concept development.…”

“…The Teacher's Guide for Chemistry: An Experimental Science (McClellan et al, 1963, p. 98), the instructor's manual used for Chem Study, states in the redox chapter that ''the point to stress here is the meaning of the equation'' that later ''takes on a molecular meaning.' ' Yuen and Lau (2022) recently offered a new method of balancing oxidation numbers that nevertheless appropriates symbolic algorithms as a benchmark for redox competency. Even the 2022 edition of AP Chemistry: Course and Exam Description defines essential redox knowledge as balancing equations from half reactions (Mui and Tully, 2022).…”

Using Buswell’s Equation to Count Quantity of Biomethane in Organochlorine Compounds

“…The H-atom method has been used to study organic combustion reactions (Yuen & Lau, 2021;2022a;2023b) and redox reactions (Yuen & Lau, 2022b). It is applied here to deduct the new general BEq of C x H y O z X w N v S u .…”

Electrical Charge Method for Balancing, Quantifying, and Defining Redox Reactions

“…The electrical charge method is a half reaction approach. The first and the most critical step is to divide an overall redox reaction into two half reactions by using the "ping-pong" strategy (Yuen & Lau, 2022a). Its working procedures are as follows: (i) choose one of the reactants and identify all its non-H and non-O elements, (ii) link the reactant's element(s) on all products' element(s), (iii) keep linking left (reactants' side)-right (products' side)-left-right…, until a half reaction is attained, (iv) choose another reactant and repeat the steps (i), (ii), and (iii).…”

“…The mathematical equation of Te -= n ∆ON among Te -, number of atoms with oxidation numbers change (n), and change of oxidation numbers (∆ON) for one set of redox couple has been established (Yuen & Lau, 2022b). In this article, the quantitative relationship between net-charge, n, and ∆ON in a half reaction is shown as:…”