What is a spot test for alcohol?

Is there a litmus test or some other test which can determine if alcohol is present in an unknown substance? Mike Jeffery

The classic test for alcohols uses chromic anhydride (CrO₃) in sulfuric acid solution. Within seconds after contacting a sample containing alcohol, the solution turns from clear orange to cloudy blue-green. Be careful- chromic anhydride in acid is extremely corrosive, poisonous, and carcinogenic.

You can detect grain, wood or rubbing alcohol with the "iodoform test". Treat the sample with iodine and sodium hydroxide; if these alcohols are present, you get a cloudy yellow precipitate (CHI₃). The test can be fooled by some ketones (for example, nail polish remover will give a positive test because it contains acetone).

Author: Fred Senese senese@antoine.frostburg.edu

General Chemistry Online! What is a spot test for alcohol?