Ketones are similar to aldehydes in there structure, but they have a -R group (methyl, ethyl, etc) instead of the hydrogen. They are often used as solvents i.e.Propanone. There are two common tests, and both of these react with the carbonyl group.
Iodoform
Iodine is added to a concentrated solution of potassium iodide, until no more will dissolve. Add about 0.5cm3 of the ketone to about 4cm3 of the iodine solution. Warm this solution, until the brown colour just dissapears. A pale yellow precipitate of iodoform is produced.
Brady's Reagent
Add a solution of 1 or 2 drops of Ketone in 2ml of 95% ethanol, to 3ml of Brady's Reagent. Shake vigorously and allow the solution to stand for about 20 minutes. An orange preciptate formed is a positive test
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