The Chemical EducatorISSN: 1430-4171 (electronic version) Abstract Volume 18
(2013) pp 061-065 Liquid-Vapor Equilibrium of a Binary Solution and Gas Chromatography: An Experiment for General Chemistry LaboratoryBidhya Kunwar, Deb Mlsna, Shawna Tazik and Todd Mlsna* Department of Chemistry, Mississippi State University, Starkville, Mississippi 39759; tmlsna@chemistry.msstate.edu Published: 22 March 2013 Abstract. Chromatography is a powerful tool, widely used in basic and applied research for a multitude of industries from medical diagnostics, to forensics to environmental monitoring. With the recent availability of miniature and portable gas chromatographs this tool is now more accessible to general chemistry students in a typical academic laboratory setting.This laboratory experiment utilizes chromatography to determine the unknown composition of the vapor above a known binary chemical mixture. In this experiment students prepare several binary mixtures at varied concentrations in a test tube or in a multi-neck flask equipped with a reflux condenser. The mixtures are warmed in a temperature controlled bath to maintain a constant temperature. Students then collect liquid and headspace vapor samples of each mixture and inject the samples into a mini GC. The mini GC is used to separate and quantify the binary components of both the liquid and vapor phase. Numerical Raoult’s law calculations are also performed to compare with experimental results.
Key Words: Laboratories and Demonstrations; analytical chemistry; gas chromatography (*) Corresponding author. (E-mail: tmlsna@chemistry.msstate.edu) Article in PDF format (393 KB) HTML format Supporting Materials: Instructor and student handouts are included in the supporting materials (596 KB)
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