BARFOED’S TESTPost Laboratory Report Group 4 Copper acetate which is present in barfoed’s reagent convert to copper oxide and give brick red precipitate when react with monosaccharide or disaccharides. they react and crystal precipitate is formed. Monosaccharde react fast while disaccharide react slowly. What is the Principle involved in the Barfoed’s Test? When barfoed reagent mix with solution of monosaccharide or disaccharide.A. and heated in boiling water bath. . . Purpose of this test Barfoed's test is a chemical test used for detecting the presence of monosaccharides.B. What components make up the Barfoed’s reagent? State the function of each component/ The reagent is prepared by dissolving copper acetate monohydrate and glacial acetic acid in water. . Acetic Acid present in the reagent hydrolyzes disacchrides to monosacchrides. Reducing monosaccharides are oxidized by the copper ion in the solution to form a carboxylic acid and a reddish precipitate of copper (I).C. Provide the type equation used in the test.D. Hi Whiteboard . . but do so at a slower rate. Show the sample equation involved in the reaction between Barfoed’s reagent and the sample which gave a positive result: RCHO + 2Cu2+ + 2H2O → RCOOH + Cu2O↓ + 4H+ Reducing monosaccharides are oxidized by the copper ion in solution to form a carboxylic acid and a reddish precipitate of copper (I) oxide within three minutes.E. Reducing disaccharides undergo the same reaction. The two monosaccharides combine together to form disaccharides which include sucrose. galactose. Provide an Explanation (POSITIVE) Monosaccharides The commonly occurring monosaccharides includes glucose. etc. ribose. lactose and maltoses . fructose.F. Result of the Test: Glucose: With brick red precipitate =POSITIVE Sucrose: No brick red precipitate =NEGATIVE Lactose: No brick red precipitate =NEGATIVE . and heated in boiling water bath. It is based on the reduction of copper(II) acetate to copper(I) oxide (Cu2O). they react and crystal precipitate is formed. Positive: Monosaccharides Barfoed's test is a chemical test used for detecting the presence of monosaccharides. . which forms a brick-red precipitate.[1][2] When barfoed reagent mix with solution of monosaccharide. Copper acetate which is present in barfoed’s reagent convert to copper oxide and give brick red precipitate when react with monosaccharide. .[3] may interfere. A number of other substances. but the reaction is much slower. including sodium chloride.) The aldehyde group of the monosaccharide which normally forms a cyclic hemiacetal is oxidized to the carboxylate.Negative: Disaccharides (Disaccharides may also react. Why is heating of the mixture limited to three minutes only? .G. but they are different in the reagents used to detect the sugars. Shows positive test for: Reducing monosaccharides . How does this test compare with Fehling’s and Benedict’s Test? Which is more accurate? all of the test is used as a general test for detecting reducing sugars.H.