Resumo: As discussões sobre as mudanças necessárias nos livros já são há muito conhecidas. Contudo, essa mudança não pode ser feita de uma hora para outra; é preciso que, aos poucos, novos materiais auxiliares sejam produzidos para ajudar nesse processo de transição entre modelos de livros. Em vista disso, construímos uma Unidade Didática Temática Contextualizada, que visa auxiliar o professor no ensino de Interações Intermoleculares a partir do processo de percepção do sabor doce. O presente artigo analisa os resultados da aplicação dessa unidade em uma disciplina de química para a graduação. Os resultados mostram que os alunos não só aprenderam os conceitos químicos, mas que utilizaram o fenômeno do sabor doce para explicá-los. Além disso, os alunos aprenderam algumas características da ligação hidrogênio, comumente ignorada nos livros didáticos. Concluímos que a contextualização realmente ocorreu e atuou como uma abordagem efetiva no processo de ensino-aprendizagem.

Abstract: Discussions about the necessary changes in textbooks have long been known. However, this change cannot be sudden. Gradually, it is necessary produce new auxiliary material to help this transition process between textbook models. Therefore, we have built a contextualized, thematic didactic unit, which aims to assist the teaching of intermolecular forces based on the process of perception of sweet taste. This article analyzes the results of the application of this unit in an undergraduate class. The results show that students not only learned the chemical concepts but also used the sweet-taste phenomenon to explain the interactions. In addition, students learned features such as the linearity of the hydrogen bond, commonly ignored in textbooks. We conclude that the contextualization was truly fulfilled and functioned as an effective approach in the teaching-learning process.

This article presents a support material to help students of the Chemistry course in the understanding of chemical concepts involved in the identification and separation of cations made in practice classes in the Qualitative Analytical Chemistry subject. The material was elaborated in the perspective of contributing to the student's learning, by dialoguing and discussing with them in these classes during a semester.

Este artículo presenta material de apoyo para auxiliar a los estudiantes del curso de química en la comprensión de los conceptos químicos involucrados en la identificación y separación de los cationes realizados en las clases de laboratorio de Química Analítica Cualitativa. El material fue elaborado con el propósito de contribuir al aprendizaje estudiantil, mediante el diálogo y la discusión con ellos en las clases de un semestre completo.

There are few didactic materials for many Chemistry courses at the undergraduate level. Texts on Qualitative Analytical Chemistry for Chemistry majors, for example, only describe experimental procedures (identification and separation of ions) without discussing the relevant chemical concepts or the relations between those concepts and laboratory procedures. In this article we describe didactic materials that emphasize the fundamental concepts involved in each stage of systematic cation analysis. The material was tested in the classroom and the data was colleted by means of questionnaires and in-class participation and observation.

The topics developed in the first discipline applied to the freshmen at the Chemistry Institute of UNICAMP are described, along with a discussion of how the program is developed in our days.

An overview of the last thirty years of the General Chemistry Course applied to the freshmen in our Institute is presented. All the changes introduced in the course since the first time it was offered up to our days are described and a discussion of the program now developed is given.