Electrolysis: What textbooks don’t tell us

Abstract

<p>We present a critical discussion of how chemistry textbooks treat the electrolysis of water and aqueous salt solutions, based on a survey of general chemistry textbooks in English and Korean at secondary and tertiary levels, also informed by the historical background of 19th-century debates. English-language textbooks present various and contradictory accounts of the electrolysis of water; a key point of disagreement is whether hydrogen and oxygen gases originate from pre-existing H⁺ and OH⁻ ions, or from the direct reduction and oxidation of H₂O molecules. School textbooks in South Korea all present the same account, with no indication of alternative views. A vast majority of all texts ignore the possibility that H₂ and O₂ may result from secondary reactions, which was a standard view in the late 19th century following the works of Daniell and Miller. Concerning the electrolysis of aqueous salt solutions, all texts give oversimplified views of competing reactions based on standard reduction/oxidation potentials. It is understandable that textbooks try to present sufficiently simple pictures that students at each level can handle; however, this should not be done in a way that shuts down questions. We recommend that students should be made aware that textbook accounts are only models, and encouraged to extend their learning beyond the models. The plausibility of our recommendations is shown in a pilot study we conducted with secondary school students in South Korea.</p>

A Review of Research on the Quality and Use of Chemistry Textbooks

“…Fifteen studies (19%) analyzed how students perceive, use, and understand the content of secondary, ,,,,,,, general chemistry, − , secondary and general chemistry, organic chemistry, and general and organic chemistry textbooks . These studies used a variety of methods: surveys, ,,,,,, surveys and interviews, , and some tested student comprehension of the textbook content with assessments. ,,,,, A subset of these studies examined student use of ebooks , or open educational resources (OERs). ,, Three of these studies asked students to complete surveys to compare ebooks/OERs and traditional textbooks ,, and two examined the difference in student assessment scores when using ebooks/OERs and traditional textbooks. , …”

Of teachers and textbooks: lower secondary teachers' perceived importance and use of chemistry textbook components

“…Aydin and Tortumlu, 2015;Phillips et al, 2015;Marniok and Reiners, 2016;Khaddoor et al, 2017) or analyses of various subject matter topics (e.g. Niaz and Costu, 2009;Osterlund et al, 2010;Bergqvist et al, 2013;Chang et al, 2020). However, there is only limited knowledge about the way textbooks affect real classroom practice.…”

Reading textual and non-textual explanations in chemistry texts and textbooks – a review

“…First, content-related research approaches focus on the analysis and evaluation of content, concepts and students' learning (Vojı ´r ˇand Rusek, 2019). For instance, articles in this research area explored how far and to what extent chemistry textbooks fail to include content about electrolysis (Chang et al, 2020) or how chemistry textbooks impact on students' conceptional confusion about acids and bases (Lembens et al, 2019).…”