Artigos científicos como recurso didático no ensino superior de Química

Chemistry teachers increasingly use research articles in their undergraduate courses. This trend arises from current pedagogical emphasis on active learning and scientific process. In this paper, we describe some educational experiences on the use of research articles in chemistry higher education. Additionally, we present our own conclusions on the use of such methodology applied to a scientific communication course offered to undergraduate chemistry students at the University of São Paulo, Brazil.

Artigos da revista Ciência Hoje como recurso didático no ensino de química

This paper presents the results from the selection and analysis of Ciência Hoje articles published from 2004 to 2009 with the aim to discuss some of their features which can assist teachers in chemistry teaching. Therefore, the articles were analyzed according to their content and format based on an analytical tool proposed by Kawamura and colleagues. The results indicate that this magazine offers a reasonable collection of articles related to chemistry with a variety of contents and approaches.

Abordagem teórico-experimental da teoria do campo cristalino na disciplina de síntese inorgânica

We describe herein the synthesis and characterization of the complexes KNiF3, [Ni(en)3]I2, [Ni(en)3]Cl2, [Ni(acac)2(H2O)2], [Ni(en)2(H2O)2]Cl2 and [Ni(NH3)6](BF4)2 (en = ethylenediamine, acac- = acetylacetonate) performed in the inorganic synthesis major course at the Chemistry Institute of UFRGS (Universidade Federal do Rio Grande do Sul). The compounds were characterized by infrared and electronic spectroscopy and the electrolytic conductivity was measured. The parameters 10Dq and B were obtained from the electronic spectra and the nefelauxetic and spectrochemical series were determined. The obtained spectrochemical series was F- < acac- < NH3 < en and the nefeulaxetic series was en < NH3 < acac- < F-.

O centenário da Teoria de Bohr

The year 2013 marks the centennial of that wondrous year in which Niels Bohr proposed a novel theory about the constitution of atoms and small molecules after which the way we regard atoms and their behaviour began to be drastically altered. Bohr drew on several sources for his original description of the atoms, most importantly on spectroscopy and Balmer's equation thereof, the new quantum hypothesis advanced a few years earlier by Planck, and the planetary atom proposed by Rutherford. Although Bohr's ideas were to be eventually overtaken by the advent of quantum mechanics, his theory was the basis of a new thinking about atoms and molecules which constitutes an invaluable asset in the development of science ever since.

Contextualizando reações ácido-base de acordo com a teoria protônica de Brönsted-Lowry usando comprimidos de propranolol e nimesulida

This paper reports the use of alternative materials for teaching experimental chemistry. In this context, nimesulide and propranolol tablets were used to teach chemical concepts about acid-base reactions according to Brönsted-Lowry protonic Theory. Important topics of Organic, Analytical and Pharmaceutical Chemistry were discussed, such as purification by acid-base extraction, solubility of organic compounds in aqueous solutions, buffers, the dissociation constant (pKa), potentiometric titration and ionization of drugs in biological fluids. The purification of propranolol and nimesulide from tablets produced yields of 75% and 90%, respectively. The experimental values of pKa for both drugs were in agreement with those from the literature.

Miten valjastaa teoria tehokkaan intervention suunnitteluun?

Kirjallisuusarvostelu

A teoria de pearson para a disciplina de química orgânica: um exercício prático e teórico aplicado em sala de aula

We report a didactic experience in teaching Pearson's theory (HSAB) to graduate students in organic chemistry. This approach was based on teaching students how to use computer programs to calculate frontier orbitals (HOMO-LUMO). The suggested level of calculation was a semi-empiric PM3, proving to be efficient for obtaining robust and fast numerical results that can be performed easily in the classroom. We described a practical computational exercise and asked students to compare these numerical data with qualitative analysis using valence bond theory. A comprehensive solution of this exercise is presented, aiming to support teachers in their lessons.

O USO DE UM SENSOR DE LUZ LINEAR COMO RECURSO DIDÁTICO PARA DEMONSTRAR PRINCÍPIOS DE DIFRAÇÃO E ESPECTROSCOPIA

This article presents a discussion on light diffraction by slits and grids as well as the development of an experimental apparatus which provides quantitative observation of the phenomenon. We conducted a brief historical survey on the evolution of the wave theory of light and the role of diffraction in the context of optical spectroscopy. We also reviewed the use of Huygens’ principle to calculate the intensity pattern obtained when light is diffracted by slits and compared the predictions with experimental results obtained using the apparatus developed. Finally, the use of the apparatus in an optical spectroscopy experiment was demonstrated.

Dinâmica molecular: teoria e aplicações em planejamento de fármacos

Dinâmica Molecular (DM) é uma ferramenta computacional poderosa usada em Química Medicinal para o planejamento racional de fármacos. DM é uma extensão da Mecânica Molecular, onde o comportamento dinâmico de um sistema molecular é simulado através da integração numérica das equações de movimento. Esta técnica tem sido usada extensivamente para auxiliar e complementar o planejamento de novos ligantes de um alvo terapêutico, bem como estimar a sua potência. Este artigo enfoca a teoria básica da DM clássica e suas importantes aplicações no planejamento racional de potenciais compostos bioativos, particularmente compostos com atividade anti-HIV.

Sobre a natureza da teoria moral de Hume

Este artigo discute duas variedades de interpretação para a teoria moral de Hume. De um lado, ela é representada como uma forma de subjetivismo e, de outro, como uma forma de realismo. Ao final, é proposto que esta filosofia pode ser melhor descrita como uma forma de intersubjetivismo.