<P> Benedict's reagent can be used to test for the presence of glucose in urine . Glucose in urine is called glucosuria and can be indicative of diabetes mellitus, but the test is not recommended or used for the diagnosis of diabetes mellitus . A false positive reaction can be due to the presence of other reducing substances in urine such as ascorbic acid (during intake of vitamin supplements), drugs (levodopa, contrast used in radiological procedures) and homogentisic acid (alkaptonuria). </P> <P> Benedict's solution is a deep - blue solution used to test for the presence of the aldehyde functional group, - CHO . It is an aqueous alkaline mixture of CuSO and sodium citrate . Here sodium citrate is the complexing agent that keeps Cu in solution, which would otherwise precipitate as cupric carbonate . The substance to be tested is heated up to 95 ° C (for example, in a water bath) with Benedict's solution; formation of a brick - red precipitate indicates presence of the aldehyde group in relatively high concentrations . Since simple sugars (e.g., glucose) give a positive test, the solution is used to test for the presence of glucose in urine, a symptom of diabetes . One litre of Benedict's solution contains 173 grammes sodium citrate, 100 grammes sodium carbonate, and 17.3 grammes cupric sulphate pentahydrate . It reacts chemically similarly to Fehling's solution; the cupric ion (complexed with citrate ions) is reduced to cuprous ion by the aldehyde group (which is oxidised), and precipitates as cuprous oxide, Cu O . </P> <Table> <Tr> <Th> Experiment </Th> <Th> Observation </Th> <Th> Inference </Th> </Tr> <Tr> <Td> Substance in water + 3ml Benedict's solution, then boil for few minutes and allow to cool . </Td> <Td> Red, green, or yellow precipitate is obtained </Td> <Td> Reducing sugar e.g. Glucose is present </Td> </Tr> <Tr> <Td> Substance in water + 3ml Benedict's solution, then boil for few minutes and allow to cool . </Td> <Td> Solution remains clear or is a little blue </Td> <Td> Reducing sugar is not present </Td> </Tr> </Table> <Tr> <Th> Experiment </Th> <Th> Observation </Th> <Th> Inference </Th> </Tr>

What color is glucose in benedict's test