Aliphatic aldehydes and reducing sugars will form a yellow-to-red precipitate with Benedict's reagent, causing the blue solution to appear green-to-red. This reaction can be used as a test for such aldehydes.
RCHO + 2Cu(citrate)22+ → RCOOH + Cu2O(s) + H2O
To Conduct Demonstration:
Safety and Disposal
Wear gloves and avoid contact with skin by solutions. Handle hot water bath with care.
D.J. Pasto and C.R. Johnson, Laboratory Text for Organic Chemistry, p 409,1979.
Margaret Asirvatham, Spring 1992