Artículos de revistas
Buffer Capacity Evaluating - A Collaborative Experiment [avaliação Da Capacidade Tamponante - Um Experimento Participativo]
Registro en:
Quimica Nova. , v. 23, n. 3, p. 405 - 409, 2000.
1004042
2-s2.0-0347367309
Autor
Silva C.R.
De Alencar Simoni J.
Institución
Resumen
The aim of this work is to show an experiment from which students can learn some of the main characteristics of buffer solutions. A mixture of some acid-base indicators, named as Yamada's indicator, can be used to estimate pH values in an acid-base titration of a buffer, with good approximation. In the experiment it is also possible to verify the relationship between the buffer capacity and the concentrations and the molar ratio of the components of a NH3 / NH4+ buffer solution. The shortage of experiments associated with the relative small importance given to many aspects of buffer solutions, is now explored with simplicity. In the proposed experiments, students prepare buffer solutions by themselves, calculate the pH, understand how acid-base indicators act and learn how buffer solutions work through graph constructed by sharing experimental data. 23 3 405 409 Russo, S.O., Hanania, G.I.H., (1987) J. Chem. Educ., 64, p. 817 Ophardt, C.E., (1985) J. Chem. Educ., 62, p. 608 Atkins, P.W., Jones, L.L., (1997) Chemistry: Molecules, Matter and Change, p. 566. , W. H. Freeman, New York Clark, R.W., White, G.D., Bonicamp, J.M., Watts, E.D., (1995) J. Chem. Educ., 72, p. 746 Morita, T., Assumpção, R.M.V., (1972) Manual de Soluçōes, Reagentes e Solventes, p. 272. , Ed Edgard Blücher Ltda