Enseignement-apprentissage de la chimie en classe de première scientifique au Cameroun : construction du concept de nombre d’oxydation par la simulation numérique comme mode de transposition didactique.

Abstract

The teaching-learning of the concepts of oxidation-reduction is all the more complex as these concepts. This study, which is part of the end thesis of the master's cycle, aims to show the contribution of numerical simulation in the construction of the concept of oxidation number by learners of the first scientific class of general education in Cameroon. To achieve this objective, a video of the numerical simulation of the electronic distribution between the atoms of a chemical species was designed; the video that the learners have followed with great attention. The distribution is made according to the electronegativity of these different atoms which constitute the chemical species. Fifty (50) learners from the Première (C and D) of the Ngoa- Ekellé high school, including twenty-five (25) from the Première D1, D3, D4 and C who constitute the control group (having participated in the classical teachings of theirs teachers) and twenty-five (25) others from the Première D2 who constitute the experimental group (having participated only in the experimental teaching-learning session). Both groups filled out the paper-and-pencil questionnaires, including the experimental group after the test (teaching-learning session on the concept of oxidation number with the use of numerical simulation). The results of this survey are such that the control group has an average percentage of correct answers of 18% and that of the experimental group has an average percentage of correct answers of 71%. The comparison of these results leads to conclude with confidence that the numerical simulation of the electronic distribution between the atoms of a chemical species significantly favors the construction of the concept of oxidation. This study also shows the limit or the unsuitability of the logicomathematic method favored in school textbooks for the curriculum and by teachers to determine the oxidation number of an atom.