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(Reference retrieved automatically from SciELO through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)


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Leandro Martínez
Total Authors: 1
Document type: Journal article
Source: Química Nova; v. 41, n. 7, p. -, Jul. 2018.

Undergraduate experiments on ionic conductivity are common practice in general chemistry and advanced physical chemistry laboratories. Often, the conductivities are measured for solutions prepared for various salts, in a range of concentrations, and the relationship between solution conductivity and concentration is interpreted in terms of the Kohlrausch law. Contaminations can dominate the conductivity of the solutions such that students might obtain unsatisfactory results for analysis. Here, the experience of using a simple experimental procedure to obtain the concentration dependence of ionic conductivities for very dilute (sub-millimolar) electrolyte solutions in undergraduate laboratories is described. The experiment consists of measuring the conductivity of solutions of increasing concentration prepared by dropping the electrolyte solution into an initial vessel of deionized water. The range of concentrations achieved is one in which the conductivities vary linearly with the concentrations, such that the molar conductivities can be obtained directly without the use of the Kohlrausch equation. The simplicity of the experimental procedure leads the students to obtain good quality results using minimal amounts of materials. Examples are presented for the conductivities of strong electrolytes, and for the weak acetic acid electrolyte, for which the conductivity is dependent on the degree of dissociation also for dilute solutions. (AU)

FAPESP's process: 13/08293-7 - CCES - Center for Computational Engineering and Sciences
Grantee:Munir Salomao Skaf
Support type: Research Grants - Research, Innovation and Dissemination Centers - RIDC
FAPESP's process: 10/16947-9 - Correlations between dynamics, structure and function in protein: computer simulations and algorithms
Grantee:Leandro Martinez
Support type: Regular Research Grants
FAPESP's process: 13/05475-7 - Computational methods in optimization
Grantee:Sandra Augusta Santos
Support type: Research Projects - Thematic Grants