A Stopped-Flow Kinetics Experiment for the Physical Chemistry Laboratory Using Noncorrosive Reagents

Stopped-flow kinetics techniques are important to the study of rapid chemical and biochemical reactions. Incorporation of a stopped-flow kinetics experiment into the physical chemistry laboratory curriculum would therefore be an instructive addition. However, the usual reactions studied in such exercises employ a corrosive reagent that can over time cause damage to sensitive and expensive components of a stopped-flow apparatus. The reduction of the dye 2,6-dichlorophenolindophenol by l-ascorbic acid at a pH of 8.5 is a reaction that provides accurate and reproducible data in the physical chemistry laboratory. Furthermore, these reagents are noncorrosive and protect instrumentation from damage.