Fernanda Esteves, M. Gabriela T. C. Ribeiro, Students learning about chemical kinetics a case study of real-time graphs, 3rd International Conference on Hands-on Science, Science Education and Sustainable Development, Braga, 2006, Proceedings, 118.
2006-09-07

Autores:
Fernanda S. Esteves
M. Gabriela T. C. Ribeiro

Instituições:
REQUIMTE, Departamento de Química e Bioquímica da Faculdade de Ciências da Universidade do Porto

Resumo:
The study of chemical kinetics is mainly experimental and involves the rate of chemical reactions and their mechanisms. The aim of this project was the study of the chemical kinetics of several chemical reactions using data-logging and real time graphs. The evaluation about the adequacy of the experiments to enhance student’ learning about chemical kinetics was also a goal. The chemical reactions chosen involved different scientific evidences and different sensors were used. The effect of initial reactants concentration on the rate of the chemical reaction was studied on the chemical reaction between sodium thiosulphate and hydrochloric acid - a light sensor was used to monitor the precipitate formation. Effect of temperature and surface area on the rate of chemical reactions was studied on the chemical reactions between metallic magnesium and hydrochloric acid and between Alka-Seltzer and water - a position sensor was used to monitor the gas evolution. The effect of catalysts on the rate of the reaction was studied on the chemical reaction between potassium permanganate and oxalic acid - a colorimeter sensor was used to monitor the changes in the colour of the solution. The chemical kinetics of these chemical reactions using these experiments was in accordance with the results obtained by other methods. The effect of these laboratory experiments on students’ understanding of chemical kinetics was studied. Seventeen students, aged 14-16 years old, were involved. Students had to plan investigations, analyze data and to formulate conclusions based on calculations and graphs. To evaluate student’ learning data were collected using several instruments: questionnaires, observation, group interviews, group discussions and participants' reflections about the work developed. The results suggested that these experiments strongly enhanced the students’ understanding of chemical kinetics and improved students’ experimental and investigative skills in using ICT in chemical laboratory.

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