A Comparative Study of French and Turkish Students’ Ideas on Acid-Base

Abstract

Some studies published in recent years have presented students' difficulties concerning concepts of acide and base (Banerjee, 1991; Drechsler and Schmidt, 2005; Hand, 1989; Lin, and Chiu, 2007; Nakhleh, 1994; Nakhleh and Karajcik, 1994; Ouertatani and Dumon, 2008; Ross and Munby, 1991; Schmidt, 1995; Toplis, 1998;...vb.). On the contrary, not comparative study between two countries has been led on the evolution in time of the level of mastering of these concepts according to knowledge to be taught. In order to understand the misconceptions better, we have examined school science curricula and textbooks so as to identify the intended development of the conceptualization of related concepts within school curricula. The knowledge to be taught for different levels is summarized as follows:. For Turkish students;. Grade 9: To recognize the essential properties of the acids and the bases,. Grade 11:. - To recognize the common properties of the acids and the bases and to give examples of the everyday life,. - To define an acid and a base in the sense of Arrhenius, Bronsted-Lowry, Lewis,. - To define the concepts of pH and pOH,. For French students;. Grade 9:. -To classify some solutions or drinks according to their "acidity". Grade 11:. -To define an acid and a base in the sense of Bronsted,. -To recognize some acide/base couples and to recognize which one is acid and which one is base: H30+/H2O, H2O/HO-(aq), NH4+(aq)/NH3(aq), CH3CO2H(aq)/CH3CO2-(aq). The purpose of this study is to highlight the acquired knowledge and difference according to knowledge to be taught at the level of upper secondary school (grades 11-12) for both French and Turkish students. We propose in this study to identify in which extent received teaching allowed the passage of description of acids and bases resting on common sense to a scientific description and to release the ideas constructed by students. Data were collected by the researcher via three teachers from France and two teachers from Turkey before the relevant teaching was conducted, using a paper-and-pencil questionnaire that included four open-ended and two multiple-choice questions from 286 French students in Pau (128 grade 11 and 158 grade 12 students); and 242 Turkish students in Karabük (119 grade 11 and 123 grade 12 students). The analysis of answers has been done through calculating the rate of students considering their levels of understanding; range of key words, and from their comparison with the expected knowledge at the end of different levels of teaching. In this study, two countries students perceptions on acid and base concepts and theirs evolution in time were examined. Moreover, models used by them to represent these concepts were identified and their reasons to choice these models have been explained. The results showed that after received teaching French students defined acids and bases using Bronsted-Lowry model. However, Turkish students used Arrhenius model, few used Bronsted model and none of them used Lewis model. Therefore, Turkish students refer to empirical register to characterize acids and bases in their explications. Turkish students defined acids and bases by color change of turnsole paper and by conductivity of electricity. However, French students take the pH values into consideration. © 2009.