Introduction to reflux

Reflux is a commonly used method of heating a reaction. When setting up apparatus for reflux, you need to clamp glassware securely, and use an appropriate heat source such as a stirrer hotplate.

The principle of the reflux operation is to safely provide a controlled amount of heat to the reaction, while ensuring that the solvent does not boil off. This is achieved by fitting a reflux condenser to the reaction vessel, so that evaporating solvent is condensed and returned to the reaction flask.