Conceptual integration of chemical equilibrium by prospective physical sciences teachers

Abstract

This article describes an empirical study concerning the mastering of the chemical equilibrium concept by prospective physical sciences teachers. The main objective was to check whether the concept of chemical equilibrium had become an integrating and unifying concept for them, that is to say an operational and functional knowledge to explain and predict chemical phenomena involving chemical equilibrium. A quantitative survey was conducted among students from various teacher training institutes of universities in France. We have tried to evaluate the preferred types of discourse used by these students for interpreting experimental situations involving chemical equilibria, to what extent they are aware of the dynamic aspect of the equilibrium state, and to how far their experimental knowledge has been improved by this concept. The results show that the concept of chemical equilibrium has not acquired the status of an integrating and unifying concept for the majority of prospective physical sciences teachers. Few of them master the concept of chemical equilibrium in a systematic and efficient way. They conceptualize chemical phenomena involving chemical equilibrium only through the chemical reaction concept. Moreover, experimental knowledge is partly dissociated from theoretical knowledge.

Pesquisa Bibliográfica: As Reações De Oxirredução De Acordo Com Os Modelos Mentais

“…O Quadro 8 mostra os trabalhos presentes em cada um dos quatro Níveis estabelecidos. 04,05,06,07,09,13,14,15,17,18,19,21,22,23,24,26,27,28,30,32,34,35,36,37,38,39,40,42,43,44,46,47,48,49,50,51,52,53,54 Conforme já mencionado, no decorrer da análise destes quatro Níveis, categorias e subcategorias emergentes foram elaboradas, desconsiderando-se aquelas formadas por apenas um artigo. Salienta-se ainda que, pelo fato de todas as cinquenta e seis publicações abordarem os modelos mentais e as reações de oxirredução, mesmo que de forma simplória e desconexa, algumas categorias e/ou subcategorias constam em mais de um Nível e que um mesmo artigo pode estar presente em mais de uma categoria e/ou subcategoria (desde que em um mesmo Nível).…”

Aprendizaje de alumnado de secundaria en una indagación guiada acerca de las disoluciones reguladoras de pH utilizando sensores y equipos de captación automática de datos

“…Para la comprensión del equilibrio químico y las dificultades de su aprendizaje, se sugieren diversas aproximaciones: un enfoque didáctico que logre que los alumnos comprendan cualitativa y cuantitativamente el concepto y vean su aplicabilidad para resolver problemas de la vida cotidiana (Moncaleano et al, 2003); el uso de analogías para ayudar a los estudiantes a entender este concepto (Raviolo y Garritz, 2008); o que los aprendices estudien cualitativamente el desplazamiento del estado de equilibrio antes de adentrarse en su estudio cuantitativo (Ganaras et al, 2008).…”

“…Otros autores (Ganaras et al, 2008) proponen una aproximación similar para el desplazamiento del estado de equilibrio en otros tipos de reacciones.…”

Teachers’ Misconceptions About the Effects of Addition of More Reactants or Products on Chemical Equilibrium

“…Although chemical equilibrium is a very important topic in the high school or college chemistry curriculum, both practicing and prospective teachers are generally weak in their subject matter knowledge (Banerjee, 1991;Ganaras, Dumon & Larcher, 2008;Özmen, 2008;Quílez, 2004;. How well do high school chemistry teachers understand the effects of adding more reactants or products on the position of equilibrium?…”