0
How is the coloured precipitate that is responsible for the positive test formed for reducing sugars?
Wiki User
∙ 12y agoWant this question answered?
Be notified when an answer is posted
Add your answer:
Earn +20 pts
What is the result of Benedict test in lactose?
I know that with Fructose it turns red and forms precipitate
Why does the starch and water solution not change color?
because orange juice contains fructose sugar. Fructose is a monosaccharide which gives a positive reaction on benedict's test. changing color indicates that the fructose gave a positive reaction.
A reducing sugar gives a precipitate of silver metal with Benedict's reagent.?
This is probable an error.
Is glucose is reducing sugar?
yes Any sugar that has an aldehyde or a ketone group in solution is termed a 'reducing sugar' Glucose is a reducing because: 1: It shows a positive to Fehling's Test for reducing sugars by forming a brick red precipitate. 2: Straight chain monosaccharides can act as mild reducing agents, because the aldehyde group that is present can be oxidized to form a carboxylic acid group and also can form a carboxylate ion group in the presence of a base. Ring form monosaccharide does not have aldehyde group thus are not consider as reducing sugars but they are readily in equilibrium with the open chain thereby becoming a reducing sugar.
Which compound gives positive Fehlings test?
Fehling test is used for reducing sugars.
Why doesn't aspartame react in Benedict's soluion?
It's not a reducing sugar. In fact, it's not a sugar at all. Benedict's solution gives a positive test, brick-red precipitate, with reducing sugars such as glucose and fructose.
What is the result of Benedict test in lactose?
I know that with Fructose it turns red and forms precipitate
Why does the starch and water solution not change color?
because orange juice contains fructose sugar. Fructose is a monosaccharide which gives a positive reaction on benedict's test. changing color indicates that the fructose gave a positive reaction.
A reducing sugar gives a precipitate of silver metal with Benedict's reagent.?
This is probable an error.
When glycogen is added to benedicts reagent why would it remains blue?
Although glycogen is a carbohydrate, it is classified under POLYSACCHARIDES which are non-reducing sugars. Benedict's reagent is used to test for the presence of non-reducing sugars. The positive result for this is a brick-red precipitate or solution. It remained blue (which is negative) due to fact that ALL POLYSACCHARIDES (such as glycogen) ARE NON-REDUCING SUGARS > I'm a Nursing Student. >M.J.T.M.E.
What are the methods of estimation of reducing sugar?
by comparing the colours or the amount of precipitate
Why cant table sugar be the positive control in test using Benedict's solution?
Table sugar, or sucrose, doesn't have an aldehyde group. Benedict's solution is used to determine if a reducing sugar is present. If it is a reducing sugar, the mixture will turn green/orange/red. The Benedict's solution contains copper (II) ions, which are reduced to a brick red precipitate of copper (I) oxide when the solution is heated. The Aldehyde (-CHO) group in a reducing sugar is the source of electrons that reduces copper (II) to copper (I). Since sucrose doesn't have an aldehyde group, it will not test positive for reducing sugars; it will not reduce the copper II in Benedict's to copper I and change the color of the solution.Fructose does not have an aldehyde group, yet it is reducing, because it gets rearranged to the reducing glucose in basic solution.All monosaccharides and some disaccharides are reducing sugars. Sucrose is one of the disaccharides that is not a reducing sugar.
What indicates a positive result for the benedicts test?
Benedict’s is used to test for glucose but not for sucrose. The test involves heating the sugar with either of the chemicals and observing the color change of blue to orange.Positive is a change of blue to orange.
Which element is the reducing agent in a red ox reaction?
The reducing agent donates electrons to an oxidant. Reducing elements become positive ions. Most metals are reducing elements.
Can you test for maltose?
Maltose is actually a reducing sugar so a test for reducing sugar could be carried out.1)Add 2cm3 of Benedict's solution to 2cm3 of maltose solution in a test tube and shake.2)Leave the test tube in a beaker of boiling water for 5 minutes.Observations:1)blue solution to green mixture- conclude that there are traces of reducing sugar2)blue solution to yellow or orange precipitate- conclude that there are moderate amt of reducing sugar3)blue solution to brick red precipitate- conclude that there are large amt of reducing sugar
give the mechanism of Benedict solution?
It is a basic oxidation/reduction reaction whereby the reducing end of a reducing sugar reduces the oxidation state of an ion (typically metal ion such as Cu2+) to a lower state such as Cu+. This new oxidation state of copper is not soluable and will precipitate to the bottom of the solution. The color of the precipitate can also be an indicator of the concentration of the sugars.
Which element is the reducing agent in a redox reaction?
The reactant that has the atom that gets oxidized
