Elementary Pre-service Teachers' Conceptions on 'the Freezing Point Depression' and a Proposal of Explanatory Models

'어는점 내림'에 대한 초등 예비교사들의 인식 조사 및 설명 모형 제안

The purpose of this study is to investigate the elementary pre-service teachers' conceptions on 'the freezing point depression' focusing on the survey from a National University of Education. Eighteen pre-service teachers who had completed high school Chemistry II coursework were selected to participate in the study. Participants answered a four question survey to measure their scientific knowledge and conceptions of this phenomenon. Each answer was qualitatively analyzed to determine whether they have 'scientific conceptions' or 'quasi-scientific conceptions' or 'misconceptions'. The results from the study are as follows: First, it was showed that none of the eighteen participants had 'scientific conceptions', six had 'quasi-scientific conceptions' and eight had 'misconceptions' about the caused effect when $CaCl_2$ is scattered on the ice. Second, it was found that three participants had 'scientific conceptions', eight had 'quasi-scientific conceptions' and two had 'misconceptions' for the second survey question. Third, ten out of eighteen participants demonstrated 'scientific conceptions' about the phenomenon of salt water freezing. Fourth, only three of eighteen participants illustrated appropriate 'scientific conceptions' for the fourth survey question. Fifth, of all participants, none answered more than three questions correctly, and only three participants answered any combination of two questions correctly. Based on the findings of this study, five explanatory models were developed. And the models were proposed for pre-service teachers to enhance their understanding of the freezing point depression phenomenon.