Common student misconceptions in electrochemistry: Galvanic, electrolytic, and concentration cells

Abstract

This study replicates, with additions, research done by Garnett and Treagust. Garnett and Treagust's interview questions for galvanic and electrolytic cells were used with modifications; concentration cell questions were asked in a similar manner. These questions were administered to 16 introductory college chemistry students after electrochemistry instruction. Student misconceptions most commonly encountered included notions that electrons flow through the salt bridge and electrolyte solutions to complete the circuit, plus and minus signs assigned to the electrodes represent net electronic charges, and water is unreactive in the electrolysis of aqueous solutions. New misconceptions identified included notions that half-cell potentials are absolute and can be used to predict the spontaneity of individual halfcells, and electrochemical cell potentials are independent of ion concentrations. Most students demonstrating misconceptions were still able to calculate cell potentials correctly, which is consistent with research suggesting that students capable of solving quantitative examination problems often lack an understanding of the underlying concepts. Probable origins of these student misconceptions were attributed to students being unaware of the relative nature of electrochemical potentials and chemistry textbooks making misleading and incorrect statements. A minor technical flaw in the Garnett and Treagust study is also addressed.

Teaching and Learning Electrochemistry

“…Sanger and Greenbowe [11] replicated research previously carried out by Garnet and Treagust. Most commonly encountered misconceptions included: notions that electrons flow through the salt bridge and electrolyte solutions; that the plus and minus signs assigned to the electrodes represent net electronic charges; that water is unreactive in the electrolysis of aqueous solutions; and that half-cell potentials can be used to predict the spontaneity of individual half-cells, while galvanic cell potentials are independent of ion concentrations.…”

“…[49] On the other hand, there are students who demonstrate misconceptions in EC, but are still able to deal successfully with these algorithmic quantitative problems. [11] Finally, non-algorithmic problems place high cognitive demands on the brain, and are therefore much more difficult for students. Tsaparlis carried out a correlation study of the role of various cognitive/psychometric factors/variables in the solution of non-algorithmic quantitative problems in elementary physical chemistry, including EC problems.…”

“…1994 Ogude and Bradley [10] Students' difficulties regarding the qualitative interpretation of the submicroscopic processes that take place in operating galvanic cells. 1997 Sanger and Greenbowe [11] Replication of the Garnet and Treagust study, including also concentration cells. 1999 Sanger and Greenbowe [12] Students' common misconceptions about galvanic cells, electrolytic cells, and concentration cells.…”

Learning Using Dynamic and Static Visualizations: Students’ Comprehension, Prior Knowledge and Conceptual Status of a Biotechnological Method

“…A number of studies related to different disciplines, mostly in chemistry, have shown that instruction involving computer animations can facilitate the understanding of chemical processes at the molecular level. For example, students who had viewed molecular-level computer animations were found less likely to demonstrate the misconception that electrons flow in aqueous solutions without the assistance of ions (Sanger and Greenbowe 1997) than students who had not. In another study, students who viewed animations illustrating the molecular processes of diffusion of perfume molecules in air, and osmosis through a selectively permeable membrane, were less likely to exhibit misconceptions regarding equilibrium, and were less likely to have anthropomorphic views of matter (Sanger et al 2001).…”

Exploring challenges of assessing pre-service science teachers’ pedagogical content knowledge (PCK)

“…The topic of electrochemistry was chosen for two reasons: convenience and our knowledge of the fact that a significant number of high school students struggle with understanding core concepts related to electrochemical cells (e.g., see Doymus, Karacop, & Simsek, 2010;Sanger & Greenbowe, 1997). The STSPCK (see Appendix) consists of three parts with 30 items.…”