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Thin-Layer Chromatography

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Thin-Layer Chromatography
PRELAB READING/VIDEO: See video on Blackboard
Zubrick: Cleaning, Chapter 9 pp. 77-79; Chromatography, Chapter 26 pp. 218-221
TLC Chapter 27 pp. 222-235, Melting Point Chapter 12 pp.88-93


The purposes of this experiment are to: (1) determine the optimal conditions for separating substances in a mixture using thin-layer chromatography (TLC), and (2) use thin-layer chromatography and infrared spectroscopy to identify an unknown solid.


thin layer chromatography, infrared spectroscopy.
This is a 2 week experiment.

Thin-layer chromatography (TLC) is a quick, inexpensive procedure that provides the chemist information on the purity of a sample, while using a minimal amount of that sample.
Chemists often use TLC after running a chemical reaction to determine the purity of their product. In this lab, you’ll be (1) determining the best solvent to use for a TLC separation of four known compounds (shown below), (2) studying how experimental parameters (the type of development chamber, the presence of a filter paper “wick,” and how well the development chamber is sealed ) affect the results of a TLC experiment, (3) determining the reproducibility of Rf values, and (4) identifying an unknown compound using TLC. Before the lab, be sure to read the chapter(s) in Zubrick on thin layer chromatography!
The four compounds you’ll be studying are shown below.

CHM25701 Spring 2015

Thin Layer Chromatography


1. Separation of substances by TLC is based on differences in what molecular property?
2. Ideally, a substance to be analyzed by TLC should be dissolved in a solvent that dissolves the substance, and also evaporates rapidly. Why are these two properties important? 3. Does the Rf value for a compound depend on the composition of the solvent...

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