First-year university students' perception of chemical bonding and bond energy

Iselin Grav Aakre,Jonas R Persson,Per-Odd Eggen,Hilde Lea Lein

doi:10.5324/njsteme.v4i2.3300

Iselin Grav Aakre, Jonas R Persson + Show 2 more

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https://doi.org/10.5324/njsteme.v4i2.3300

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Abstract

First-year university students’ knowledge and conceptual understanding of general chemistry has been investigated using a multiple-choice concept inventory (Chemical Concept Inventory 3.0/CCI 3.0) as a pre-test (n = 221) and a post-test (n = 90) in two first-semester chemistry courses. This paper discusses the students’ answers to two questions about bond energy. Student interviews (n = 7) were performed for further insight in the students’ thought processes and validation of the CCI questions. Although many students appeared to recall that breaking a chemical bond demands energy, most were not able to use this fact to reason about the heat released in a chemical reaction, and the alternative conception that bond breaking releases energy seemed deeply ingrained and prevalent among the students. For one of the questions, more students gave the correct answer on the pre-test than on the post-test. Student interviews indicated that some students’ failure to pick the correct alternative for this question might be influenced by use of the word “always” in the correct answer, which discouraged those students that find chemistry to be a subject full of exceptions.

Highlights

A chemical bond is a lasting electrostatic attraction that holds the atoms in a chemical compound and components of a solution together
4 RESULTS Table 1 gives the results from the CCI 3.0 for the two chemistry courses and shows the number of answers, percentage correct answer for the two selected questions, and the average total test score
In plain words: a significant portion of the students – more than half of those that answer question 1 (Q1) correctly – contradict themselves. This implies that the students lack a consistent framework for chemical bonding and bond energy, and confirms the findings previously reported by Boo (1998) and Barker and Millar (2000)

Summary

Introduction

A chemical bond is a lasting electrostatic attraction that holds the atoms in a chemical compound and components of a solution together. A chemical reaction is what happens when some bonds break and other bonds form. This makes chemical bonding an essential concept in chemistry. It is a complex and abstract concept that is shown to be commonly misunderstood among learners (Taber and Coll, 2002). This paper investigates university students’ conceptual understanding of chemical bonding and bond energy by use of a concept inventory and student interviews and relates the findings to previously published results. 2.1 ALTERNATIVE CONCEPTIONS RELATED TO CHEMICAL BONDING AND BOND ENERGY In constructivist learning theory, the learner constructs her own knowledge system in order to make sense of the world around her (Taber, 2000a). Much of the research focuses on secondary school students, but similar alternative conceptions have been found across several age groups, including university students (Nicoll, 2001; Coll and Taylor, 2002; Coll and Treagust, 2003; Galley, 2004)

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