Science and Technology for UPSC Examinations [Chemistry] Part 19- Carbonyl Compounds – Ketones

Like aldehydes, ketones also contain carbonyl group, >C=O. Therefore, ketones are also known as carbonyl compounds. Ketones have two alkyl groups attached to carbonyl carbon

where R and R’ are alkyl groups.

Acetone

Acetone is the first member of the ketone series. Its IUPAC name is propanone. The chemical formula of acetone is CH3COCH3. It is prepared by the dehydrogenation of isopropyl alcohol using heated copper.

Properties & Applications of Acetone

• Acetone is a colorless, inflammable, volatile liquid with characteristic pleasant smell. Its boiling point is 329 K. It is miscible with water, alcohol and ether in all proportions. It specific gravity is 0.792 g/ml at 293K
• About a third of the world’s acetone is used as a solvent, and a quarter is consumed as acetone cyanohydrin a precursor to methyl methacrylate, which is further used to create plastic called polymethyl methacrylate (PMMA)
• Acetone is a good solvent for most plastics and synthetic fibers including those used in laboratory bottles made of polystyrene, polycarbonate and some types of polypropylene. It is ideal for thinning fiberglass resin, cleaning fiberglass tools and dissolving two-part epoxies and superglue before hardening. It is used as a volatile component of some paints and varnishes. As a heavy-duty degreaser, it is useful in the preparation of metal prior to painting; it also thins polyester resins, vinyl and adhesives. It is also useful for high reliability soldering applications to remove solder rosin after soldering is complete. This helps to prevent the Rusty bolt effect from occurring due to dirty solder contacts.
• It is also used in the synthesis of rubber, in the manufacture of artificial leather, to clean and dry the parts of precious equipments and as a nail polish remover.