Artículos de revistas
Visual Demonstration Of The Ionic Strength Effect In The Classroom. The Debye-hückel Limiting Law
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Quimica Nova. , v. 36, n. 1, p. 187 - 189, 2013.
1004042
10.1590/S0100-40422013000100031
2-s2.0-84874504564
Author
Sabadini E.
Carvalho L.V.C.
Institutions
Abstract
The effects of ionic strength on ions in aqueous solutions are quite relevant, especially for biochemical systems, in which proteins and amino acids are involved. The teaching of this topic and more specifically, the Debye-Hückel limiting law, is central in chemistry undergraduate courses. In this work, we present a description of an experimental procedure based on the color change of aqueous solutions of bromocresol green (BCG), driven by addition of electrolyte. The contribution of charge product (z +|z-|) to the Debye-Hückel limiting law is demonstrated when the effects of NaCl and Na2SO4 on the color of BCG solutions are compared. 36 1 187 189 Atkins, P.W., (1998) Physical Chemistry, , 7th ed., Oxford University Press: Oxford Levine, I.N., (1983) Physical Chemistry, , 2nd ed., McGraw-Hill Book Company: New York Silva, C.R., Pereira, R.B., Sabadini, E., (2001) J. Chem. Educ., 78, p. 939