Silmar J S Franchi

In accordance with some specialists, chemistry teaching must be centered in the chemical knowledge and the social context. A chronicle narrates facts and events, through its own linguistic structures, in contrast to the eloquence of the great literary classics and of the classic approach of the textbooks of Chemistry. The short narrative, focused on everyday themes, allows the chronicles to be accessible, from the point of view of reading and written production. The proposal of using the chronicles in the teaching of chemistry, through a multimodal approach, evidences multiple possibilities of learning and conceptual change, highly desirable for the learning of the sciences. In this article, we discuss the use of Chronicles for Chemical Teaching, who consists in a good alternative to provide a better interaction between the student and the chemical knowledge. It would consist in an additional tool to be used by the teacher. We present two chronicles, that can be used in classrooms, for the deepening of contents involving the area of chemistry, desirable to the learning of the sciences.

This work describes the synthesis, characterization, and the thermal behavior investigation of four palladium(II) complexes with general formulae [PdX2(mba)2], in which mba = N-methylbenzylamine and X = OAc− (1), Cl− (2), Br− (3) or I− (4). The complexes were characterized by elemental analysis, infrared vibrational spectroscopy, and 1H nuclear magnetic resonance. The stoichiometry of the complexes was established by means of elemental analysis and thermogravimetry (TG). TG/DTA curves showed that the thermodecomposition of the four complexes occurred in 3–4 steps, leading to metallic palladium as final residue. The palladium content found in all curves was in agreement with the mass percentages calculated for the complexes. The following thermal stability sequence was found: 3 > 2 > 4 > 1. The geometry optimization of 1, 2, 3, and 4, calculated using the DFT/B3LYP method, yielded a slightly distorted square planar environment around the Pd(II) ion made by two anionic groups and two nitrogen atoms from the mba ligand (N1 and N2), in a trans-relationship.

O presente livro visa abordar a temática do Ensino de Química em seus diferentes aspectos e contextos, como o processo de ensino-aprendizagem, uso das TICs, o Ensino de Química no ambiente virtual, propostas inovadoras no Ensino de Química em cursos de graduação em Química, relação professor-aluno, o Ensino contextualizado da Química, o Ensino de Química na pandemia, entre outros.

Complexes of Ni(II), Co(II), Cu(II), Cd(II), Hg(II), and U(VI)O2 with 2-(2-(3,4-dihydronaphthalenylidene)hydrazinyl)-2-oxo-N-phenylacetamide (H2NHPA) have been prepared and characterized by elemental analysis, molar conductance, thermal (TG, DTG), spectral (H NMR, IR, UV–Vis, ESR), and magnetic measurements. IR spectra show that H2NHPA is a bidentate ligand. Thermal decomposition of some complexes ended with metal oxide as a final product. The room temperature solid

De acordo com alguns especialistas, o Ensino de Quimica deve estar centrado no conhecimento quimico e no contexto social. Na busca por alternativas para um ensino de quimica contextualizado, propusemos que o uso de cronicas poderia se constituir em uma boa alternativa por proporcionar uma melhor interacao entre o aluno e o conhecimento quimico. Ela se constituiria em uma ferramenta a mais a ser utilizada pelo professor, em conjunto com sua atividade e seu planejamento. Neste trabalho, desenvolvemos um conjunto de quinze cronicas, das quais ?De Olho na Natureza e nas Interacoes Intermoleculares?, ?Namorados no Ponto... de Ebulicao? e ?La na Pescaria...? foram aplicadas e avaliadas junto a alunos do Ensino Medio de uma escola da rede publica, localizada em Campinas, Sao Paulo. Fizemos a avaliacao das cronicas por meio de um questionario, no qual buscamos perceber a opiniao dos alunos sobre as mesmas, bem como se existiam dificuldades para a sua interpretacao e entendimento. Buscamos, ...

This work describes the synthesis, characterization, and the thermal behavior investigation of four palladium(II) complexes with general formulae [PdX2(mba)2], in which mba = N-methylbenzylamine and X = OAc− (1), Cl− (2), Br− (3) or I− (4). The complexes were characterized by elemental analysis, infrared vibrational spectroscopy, and 1H nuclear magnetic resonance. The stoichiometry of the complexes was established by means of elemental analysis and thermogravimetry (TG). TG/DTA curves showed that the thermodecomposition of the four complexes occurred in 3–4 steps, leading to metallic palladium as final residue. The palladium content found in all curves was in agreement with the mass percentages calculated for the complexes. The following thermal stability sequence was found: 3 > 2 > 4 > 1. The geometry optimization of 1, 2, 3, and 4, calculated using the DFT/B3LYP method, yielded a slightly distorted square planar environment around the Pd(II) ion made by two anionic groups...