Absolute alcohol

Absolute alcohol or dehydrated alcohol is anhydrous pure ethanol, (C₂H₅OH) containing no more than one percent water.

It is not possible to obtain absolute alcohol by simple fractional distillation, because a mixture containing at least 95.4% alcohol and 5.6% water becomes a constant boiling mixture (an azeotropic mixture). To obtain 100% pure alcohol a small quantity of benzene is added to rectified spirit and the mixture is then distilled. Absolute alcohol is obtained in third fraction that distills over at 351.3°K (78.2°C).

There is also an absolute alcohol production process by dehydration using glycerine.

External links

• Specifications
• Safety data