Aim
The aim of this study is to investigate students’ understanding of the energy concept in chemical reactions particularly in endothermic-exothermic reactions. Both qualitative and quantitative methodology was used for this investigation. A twenty-item multiple choice test was developed about the topic to measure the students’ understandings. This concept test was prepared based on students’ conceptual difficulties and misconceptions related to the energy in chemical reactions found in the literature. In addition, semi structured interviews were conducted to get deep knowledge about students’ perceptions.
Methodology
222 Turkish high school students from different high schools participated in this study. 103 of them were female whereas the others were male students. These were 10th grade students who had already learnt energy in chemical reactions concept. In this study, data was collected using two tests; Energy in Chemical Reactions Concept Test (ECT) which consisted of 20 multiple-choice questions and was applied to all the participants and Semi-structured interviews which were used to supplement the analysis of the test results. The latter were carried out with 7 students who completed the ECT test. Based on frequency analysis, students with different misconceptions were selected. Before the interviews, a semi-structured interview schedule was prepared considering students’ responses in the test. Each interview lasted about 30 minutes.
Results
Analysis of responses from the questions given to students revealed that 76.9% of them did not have difficulties in identifying burning of candle, copper and darkening of silver as exothermic reactions. However, 60% of students considered all reactions occurring spontaneously as exothermic. In addition, approximately 30% of the students thought that heat was always needed for