Science, Tech, Math › Science Ketone Definition What Is a Ketone in Chemistry? Share Flipboard Email Print This is the chemical structure of the ketone acetone. Todd Helmenstine Science Chemistry Chemical Laws Basics Molecules Periodic Table Projects & Experiments Scientific Method Biochemistry Physical Chemistry Medical Chemistry Chemistry in Everyday Life Famous Chemists Activities for Kids Abbreviations & Acronyms Biology Physics Geology Astronomy Weather & Climate by Anne Marie Helmenstine, Ph.D. Dr. Helmenstine holds a Ph.D. in biomedical sciences and is a science writer, educator, and consultant. She has taught science courses at the high school, college, and graduate levels. Updated March 08, 2017 Ketone Definition A ketone is a compound containing a carbonyl functional group bridging two groups of atoms.The general formula for a ketone is RC(=O)R' where R and R' are alkyl or aryl groups.IUPAC ketone functional group names contain "oxo" or "keto". Ketones are named by changing the -e on the end of the parent alkane name to -one. Examples: Acetone is a ketone. The carbonyl group is connected to the alkane propane, therefore the IUPAC name for acetone would be propanone. Continue Reading