Spectroscopic, Chromatographic, and Visual Investigation of Organic Dyes

TCE

The Chemical Educator

ISSN: 1430-4171 (electronic version)

Table of Contents

Abstract Volume 2 Issue 1 (1997), S1430-4171(97)01108-4

Spectroscopic, Chromatographic, and Visual Investigation of Organic Dyes

Dale Russell,* Curtis Olson, Susan Shadle, and Martin Schimpf

Department of Chemistry, Boise State University, Boise, ID 83725

Published online: 16 April 1997

Abstract. An introductory level laboratory experiment is presented in which students learn about color using spectroscopy and chromatography. The pedagogical approach is discovery-based; students are given only enough background information to enable them to take good data. Commercially available dyes are dissolved in water to make concentrated stock solutions, which students then dilute to prepare solutions of primary, secondary and tertiary colors. The class works as a team to study colored solutions representing a range of concentrations and combinations of the three primary colors: cyan, yellow, and magenta. Students record transmission and absorption spectra and compare the results with human perception. They show the number of components in each solution by paper chromatography. They explore the filter nature of dyes, the effects of concentration, and the cumulative effects of mixing dyes. From this information they deduce the principles of color printing. The experiment is best performed with a photodiode array spectrophotometer; alternative approaches include spectrometers and simple spectroscopes which the students make from cereal boxes. The experiment can be performed in either a single three-hour laboratory period, or alternatively, three one-hour sessions.

Key Words: Laboratories and Demonstrations; spectroscopy; chromatography; organic; organic dyes; laboratory; general chemistry

(*) Corresponding author. (E-mail: drussel@quartz.boisestate.edu)

Article in PDF format (230 KB )

Supporting Materials:

21da1897.pdf (53 KB)10.1007/s00897970108b