Hydrolysis of 2-Chloro-2-methylpropane—Demonstration Using the Quenching of Fluorescence from Fluorescein

Abstract

2-Chloro-2-methylpropane slowly hydrolyzes in water, releasing hydrochloric acid. Therefore, the addition of 2-chloro-2-methylpropane to an aqueous solution of sodium hydroxide containing an acid–base indicator causes a color change when the solution becomes acidic. Here we report the use of fluorescein, a fluorescent dye, as an indicator for the completion of the above-mentioned reaction. Under blacklight radiation, completion of the reaction is marked by the disappearance of fluorescence. Compared with the other clock reactions, this fluorescent reaction is more advantageous because it requires inexpensive reagents and involves milder conditions, and it is expected to be utilized in chemistry outreach events. Furthermore, the demonstration can be easily understood by high school students since the reaction mechanism can be explained well by changing the pH, and it is suitable for practice in the classroom.