How Do You Separate Alcohol and Water?

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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.

  1. 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.

  2. 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.

  3. 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.

  4. 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.