Test For Ketonic Group in Organic Compound

Ketones do not give Fehling's and Tollen's tests. Ketones give the following two tests which are not given by aldehydes.

1. m-Dinitrobenzene Test

To a mixture of finely powdered m-dinitrobenzene and an equal amount of organic compound, add dilute sodium hydroxide solution. The appearance of red colour indicates the ketonic group.

2. Sodium Nitroprusside Test

To the given organic compound, add sodium nitroprusside solution and a little sodium hydroxide solution. Appearance of red-violet colour confirms the presence of ketonic group.