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Sucrose gives a negative reaction to the Benedict's reagent test because it is a non-reducing sugar. Benedict's reagent is used to test for the presence of reducing sugars, which have the ability to reduce the copper ions in the reagent. Since sucrose does not have this ability, it does not give a positive reaction.
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Why sucrose does not give a positive Benedict's test but hydrolyzed sucrose does give a positive beneditcts test?
Sucrose does not contain a free aldehyde or ketone group needed to reduce Benedict's reagent, so it does not give a positive Benedict's test. When sucrose is hydrolyzed into glucose and fructose by acid or enzymes, the resulting glucose can then react with Benedict's reagent due to the presence of the free aldehyde group, producing a positive test result.
What is the chemical equation for the reaction between glucose and Benedict's reagent?
The chemical equation for the reaction between glucose and Benedict's reagent (CuSO4) is: C6H12O6 (glucose) + 2CuSO4 + 4NaOH -> Cu2O (reddish precipitate) + H2O + Na2SO4. The color change from blue to brick-red indicates the presence of reducing sugars like glucose.
Does starch gives positive result for Benedict test?
Yes, starch does not give a positive result for the Benedict test because starch is a complex carbohydrate composed of multiple glucose units linked together in long chains. Benedict's reagent is used to test for the presence of reducing sugars, such as glucose and fructose, which can reduce the copper ions in the reagent, causing a color change. Starch does not have the ability to reduce the copper ions in Benedict's solution.
What reaction occurs when benzil gives tollens test?
Benzil does not react with Tollens reagent because it does not contain aldehyde or ketone functional groups. Tollens reagent is a silver mirror test used for the detection of aldehydes in a sample by the reduction of silver ions to metallic silver. Benzil, being a diketone, does not undergo this reaction.
How do you distinguish between glucose and maltose using Benedicts reagent?
Glucose gives a positive reaction with Benedict's reagent and forms a brick-red precipitate. Maltose, on the other hand, also gives a positive reaction but forms a lighter green to yellow precipitate. The color change can help distinguish between the two sugars when using Benedict's reagent.
A reducing sugar gives a precipitate of silver metal with Benedict's reagent.?
This is probable an error.
What substrate gives a positive reaction for benedicts reagent?
Reduction of Benedict's reagent occurs with reducing sugars such as glucose, fructose, and galactose, giving a positive test result. This test is used to detect the presence of reducing sugars in various food products.
What is the difference between Benedict's Reagent and Biuret Reagent?
Benedicts reagent is used to check reducing sugars , it need hat to work and gives red color when positive ,. While biuret reagent is for proteins .there is no need to use heat and gives purple , violet color when positive ..
Why sucrose does not give a positive Benedict's test but hydrolyzed sucrose does give a positive beneditcts test?
Sucrose does not contain a free aldehyde or ketone group needed to reduce Benedict's reagent, so it does not give a positive Benedict's test. When sucrose is hydrolyzed into glucose and fructose by acid or enzymes, the resulting glucose can then react with Benedict's reagent due to the presence of the free aldehyde group, producing a positive test result.
Is Pararosaniline is schiff's reagent?
Yes, pararosaniline is one of the primary components of Schiff's reagent, which is commonly used in histology and staining techniques to detect aldehydes and identify carbohydrates.
Sugar in blood and urine is tested with which solution?
Sugar in blood and urine is tested with Benedict's solution.
What is the chemical equation for the reaction between glucose and Benedict's reagent?
The chemical equation for the reaction between glucose and Benedict's reagent (CuSO4) is: C6H12O6 (glucose) + 2CuSO4 + 4NaOH -> Cu2O (reddish precipitate) + H2O + Na2SO4. The color change from blue to brick-red indicates the presence of reducing sugars like glucose.
What is Benedict test for?
The Benedict test is used to detect the presence of reducing sugars, such as glucose and fructose. It involves adding Benedict's reagent to a sample, then heating it to observe a color change. A positive result is indicated by a color change to green, yellow, orange, or brick red, depending on the concentration of reducing sugars present.
Is fructose gives positive test with tollens reagent?
Fructose does not give a positive test with Tollens' reagent because it is a reducing sugar that does not have a free aldehyde group capable of reducing the Tollens' reagent. Tollens' reagent is typically used to detect the presence of aldehydes but may not react with fructose due to its ketone functional group.
Does starch gives positive result for Benedict test?
Yes, starch does not give a positive result for the Benedict test because starch is a complex carbohydrate composed of multiple glucose units linked together in long chains. Benedict's reagent is used to test for the presence of reducing sugars, such as glucose and fructose, which can reduce the copper ions in the reagent, causing a color change. Starch does not have the ability to reduce the copper ions in Benedict's solution.
Why is Benedict's test unreliable?
Benedict's test is considered unreliable because it can give false positive or false negative results. It may not accurately differentiate between reducing sugars and other substances that can also react with the Benedict's reagent, leading to inaccurate conclusions about the presence of sugars in a sample. Additionally, the test may not detect certain types of sugars or may give inconsistent results depending on factors such as temperature and pH.
When does a spray of diphenylamine reagent on TLC gives blue coloration?
Diphenylamine is a reagent for DNA.
