Fernanda Esteves, M. Gabriela T. C. Ribeiro, Having fun learning about chemical kinetics, Students learning about chemical kinetics a case study of real-time graphs, 3rd International Conference on Hands-on Science, Braga, 2006, Proceedings,148.
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 can be fun, especially when investigative experimental work is combined with data-logging and ICT.
The addition of hydrochloric acid to a sodium thiosulphate solution makes possible that the thiosulphate ions react with the hydrogen ions.
During the chemical reaction the formation of a sulphur precipitate can be observed. This precipitate interferes with a beam of light that is transmitted trough the solution, diminishing its intensity at the sensor receptor. The variation of light intensity transmitted trough the solution is monitored using a light sensor.
To study the effect of reactants initial concentration on the rate of this reaction sets of sodium thiosulphate solutions and hydrochloric acid with different concentrations were used.
The analysis of graphs representing the decrease in light intensity transmitted through the solution along time, for the different essays, allows us to determine the time interval needed to the formation of a certain quantity of precipitate. As the rate of the chemical reaction in inversely proportional to that time, it is possible to evaluate the effect of the initial concentration of reactants on the rate of this chemical reaction.

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Having fun learning about chemical kinetics .pdf