CONSTRUÇÃO E AVALIAÇÃO DE UM FOTÔMETRO DE CHAMA ALTERNATIVO PARA EXPLORAÇÃO EM AULAS DE QUÍMICA DE NÍVEL MÉDIO

Abstract

At an exponential pace, contemporary society has been undergoing changes and innovations in various areas of science, this fact is justified by the need to provide promising alternatives in the educational sphere. From this perspective, an alternative flame photometer was designed and developed in the Chemistry laboratory of the Federal Institute of Education, Science and Technology of Paraíba – IFPB Campus João Pessoa, to be used in high school experimental Chemistry classes, exploring spectroscopy concepts. . The concepts of spectroscopy are important in discussions about atomic models and their evolution over the years, they are also important to explain how some chemical analyzes are carried out using instrumental procedures. The instrument was built with low-cost materials and allows emission spectra to be obtained in the flame of some metals from burning alcoholic solutions of salts of these elements. To obtain the emission spectra, a thimble was used as a sample container and a fragment of CD was used to diffract the polychromatic radiation emitted by the elements in the flame and direct the emission spectrum to the camera of a cell phone that records the data. This procedure was used for qualitative analyzes of elements in the flame and allowed the characterization of some characteristic spectra of the elements. To carry out quantitative analyses, the images of the recorded spectra were evaluated using the ChemEye application, a chemical analysis application using digital images. By evaluating the variations in color intensities in the yellow spectral region obtained from sodium solutions in the concentration range of 10 to 40ppm, it was possible to verify a linear behavior between the recorded signals and parameter B (blue channel) of the RGB color system, with a linear correlation coefficient r=0.9838. With the flame photometer developed, it is possible to carry out low-cost experiments contextualizing spectroscopy concepts normally presented theoretically and with a lot of abstraction in high school classrooms, facilitating the teaching-learning process and being essential for showing the student a concept most accentuated of Science.