Methyl Red: A Chameleon That Reveals The Partition Between Two Phases As A Function Of pH. An Extraction Experiment

JAZMÍN SILVERO; FABIO E. MALANCA; CESAR G. GOMEZ; JUAN C. FRAIRE; GERARDO A. ARGÜELLO

The Chemical Educator

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Año: 2012 vol. 17 p. 163 - 165

1430-4171

A picture is worth a thousand words,” and besides it is easier to remember. Thiswork is based on that premise, and its main objective is to show that creating a strong visual impact on the student’s mind is a useful tool to teach important chemistry concepts. The activities proposed involve a biphasic medium composed of an aqueous solution at different pH levels and petroleum ether (60–80C), where an acid-basic indicator such as methyl red is employed to examine the phenomenon occurring in each phase, as it changes its color like a “chameleon.” During the process, students are introducedto core concepts of physical chemistry through a solvent partition system. The experiment is suitable for both qualitative and quantitative analyses of the extraction process