A grandeza "quantidade de matéria" e sua unidade "mol" : uma proposta de abordagem histórica no processo de ensino-aprendizagem

Detalhes bibliográficos
Ano de defesa: 2006
Autor(a) principal: Soares, Maria Aparecida do Carmo Padulla
Orientador(a): Não Informado pela instituição
Banca de defesa: Não Informado pela instituição
Tipo de documento: Dissertação
Tipo de acesso: Acesso aberto
Idioma: por
Instituição de defesa: Universidade Estadual de Maringá
Brasil
Programa de Pós-Graduação em Educação para a Ciência e o Ensino de Matemática
UEM
Maringá, PR
Centro de Ciências Exatas
Programa de Pós-Graduação: Não Informado pela instituição
Departamento: Não Informado pela instituição
País: Não Informado pela instituição
Palavras-chave em Português:
Mol
Link de acesso: http://repositorio.uem.br:8080/jspui/handle/1/4507
Resumo: The chemical quantity "amount of substance" and its unity "mol" are badly understood by teachers and students of all levels, as attested by some research on this subject. Even in textbooks these concepts are introduced in a non-contextualized way, leading to a lack of comprehension. These two ideas are very important since they perform a conceptual bridge between the macro world of perceptible quantities (mass and volume of reactants) and the micro domain of the abstract and conceptual approach (atoms, molecules and number of particles participating in a chemical reaction). In this work we recover the historical evolution of stoichiometry since its origin, with the introduction of equivalent weight, by the end of the XVIII century until the consolidation of the chemical quantity "amount of substance", by the middle of the XX century. These two concepts deals with the same problem, e.g., the ratio among the amount of reactants that perform chemical reactions, but from two different (equivalentist and atomistic) points of view (different paradigms). The combination laws of Richter, Proust and Gay-Lussac, and the Dalton and Avogadro´s hypothesis are discussed, as well as the introduction, by Ostwald, in 1900, of the term "mol" as a unity of mass, in his equivalentist view. We stress that the complete understanding of "amount of substance" and "mol" can be achieved only if one comprehends the historical evolution from the continuous (mass and volume) to discrete (atoms, molecules and number of particles) concepts involved in chemical reactions.