Preparation of Propanone (Acetone), CH3 - CO - CH3
By Dehydrogenation of Propan-2-ol
Acetone is prepared by dehydrogenation of propan-2-ol using heated copper.
By Dry Distillation of Calcium Acetate
It can also be prepared by dry distillation of calcium acetate.
By Wacker Process
Acetone can also be prepared from propene by Wacker Process. In this process a gaseous mixture of propene and air is passed through a solution of copper (II) chloride and palladium (II) chloride between 293k to 333k.
Acetone is also formed as by-product during the manufacture of phenol from cumene.
Properties of Acetone
Physical Properties
- Acetone is a colourless, inflammable, volatile liquid with characteristic sweetish smell. Its boiling point is 56oC.
- It is miscible with water, alcohol and ether in all proportions.
- It specific gravity is 0.792 at 293k
Chemical Properties
Addition of Hydrogen Cyanide
When acetone is treated with sodium cyanide and dilute sulphuric acid, a cyanohydrin is formed due to addition of hydrogen cyanide to the carbonyl group.
Addition of Sodium bisulphate
When acetone is treated with a saturated solution of sodium bisulphate, a crystalline addition product is formed.
Addition of Grignard Reagents
Grignard reagents on reaction with acetone, followed by hydrolysis yield alcohols.
Haloform Reaction
Acetone on reaction with iodine in the presence of sodium hydroxide, yields yellow crystalline precipitate of iodoform.
Reduction
Acetone can be reduced to 2-propanol by reaction with lithium aluminum hydride.
Acetone can be reduced to propane by reaction with zinc-amalgam and hydrochloric acid.
This reaction is known as Clemmensen reduction.
Uses of Acetone
- It is used as solvent in paints, varnishes and lacquers
- It is used as delusterant (removes the lustre from a textile) for cellulose acetate fibres
- It is used in the preparation of cordite (smokeless gun powder) and plexiglass (unbreakable glass)
- It is used for specification testing of vulcanised rubber products
- It is used as nail polish remover
- It is used to clean and dry parts of precision equipment
