To separate alcohol from water, you must heat the solution, evaporate the ethanol into vapor, cool it down and condense it back into a liquid using a distillation apparatus. This process is called distillation, and it is used to separate a pure liquid from a liquid mixture. Distillation works for liquids that have different boiling points.
- Heat the water and alcohol mixture
Add the mixture to a flask, and position the flask on a stand. Add a boiling chip to the flask. Position the heat source (open flame or heating plate) underneath the flask, turn it on and maintain a constant temperature.
- Evaporate the alcohol
Continue heating until the alcohol has turned into vapor. Alcohol evaporates before water because it has a lower boiling point, and the thermometer remains at the alcohol-vapor temperature until water begins to evaporate. Keep the temperature stable. A rise in temperature indicates impure alcohol. Turn off the heat when you have evaporated all the alcohol from the mixture.
- Cool the ethanol vapor
The ethanol vapor is cooled through a cold water circulation system attached to the apparatus. Allow it to cool, and it moves through the apparatus to the condenser.
- Condense the vapor into a liquid
The cooling vapor condenses in the condenser and drips into a catching flask. Allow the distillate to cool before using the alcohol for analysis.