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Microscale Determination of Vitamin C by Weight Titrimetry

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Gaston A. East and Erica C. Nascimento

Instituto de Química, Universidade de Brasilia, Brasilia, DF, Brazil

J. Chem. Educ., 2002, 79 (1), p 100

DOI: 10.1021/ed079p100

Publication Date (Web): January 1, 2002

Abstract

A laboratory experiment involving the quantitative microscale determination of ascorbic acid in pharmaceutical tablets of vitamin C by weight-titrimetry using (diacetoxyiodo)benzene as titrant and differential electrolytic potentiometry to locate the end-point is presented. The experiment affords an opportunity for students to explore nonconventional techniques such as the use of a novel organic oxidimetric titrant, titration in a semiaqueous medium, gravimetric titration, and an electrometric method of end-point detection using polarized electrodes. Synthesis, purification, and purity checking of the titrant may also be included in the project. Some advantages of the method are very low reagent consumption, low-cost equipment, improved sensitivity, and high precision and accuracy. Furthermore, the experiment will help the student to relate chemical analysis to everyday life.

Keywords (Audience):

Second-Year Undergraduate

Keywords (Domain):

Analytical Chemistry

Keywords (Feature):

Advanced Chemistry Classroom and Laboratory

Keywords (Pedagogy):

Hands-On Learning / Manipulatives

Keywords (Subject):

Electrochemistry

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This article has been cited by 2 ACS Journal articles (2 most recent appear below).

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