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Why sucrose solution when mixed with hydrochloric acid will give a positive result in Benedict's test?
Wiki User
∙ 14y ago
In acidic solution (also in e.g. sugar containing limonades),
the nonreducing di-saccharide sucrose is quit easily turned ('hydrolysed' or split) into
the two mono- saccharides glucose and fructose, which are in fact (in this test) reducing.
- The aldose glucose is a straight forward reducing sugar, so positively detected by B's test reagent.
- The ketose fructose is not strictly a reducingsugar (it is an alpha-hydroxy-ketone, not an aldehyde), but it becomes reducing thus giving a positive test.
This is because this 'alpha-hydroxy-ketone' is converted to the aldoses: glucose and mannose, by the alkaline solution of the Benedict's test (called 'keto-enol'-tautomerisation).
Wiki User
∙ 14y ago
Wiki User
∙ 12y agono
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Why do you add hydrochloric acid to the hydrolysis of sucrose?
HCl In solution. H + and Cl - An easy hydrolysis with this strong acid.
Is a mixture of sucrose and water a solution?
Sucrose is the name for the common sugar compound. A sucrose solution is a solution made of sugar dissolved in water.
Why is hydrochloric acid used when testing for non-reducing sugars?
to hydrolise sucrose solution into a monosaccharide ( glucose and fructose )
What is the molarity of a solution of sucrose that contains 125g of sucrose in 3.50 L of solution?
Molarity (M) represents the moles of a solute per liter of a solvent. In this case, sucrose is the solute and water is the solvent. First, convert your 125g of sucrose to moles...molar mass of sucrose = 342.34 soo you have .365 moles of sucrose. Since you have exactly one L of solution, the molarity of the solution is .365 M Molarity (M) represents the moles of a solute per liter of a solvent. In this case, sucrose is the solute and water is the solvent. First, convert your 125g of sucrose to moles...molar mass of sucrose = 342.34 soo you have .365 moles of sucrose. Since you have exactly one L of solution, the molarity of the solution is .365 M
Can sucrose conduct electricity as a solid or in-solution?
Sucrose can not conduct significant electric currents in either solid form or in solution in water, because sucrose does not contain ions in its solid form and does not ionize when it dissolves in water.
Would sucrose test positive or negative with benedicts reagent?
No, surcose is a disaccharide without a hemiacetal group
Why does sucrose not react to Benedicts when glucose and fructose its components do?
Fructose and glucose are joined by their glycosidic bond in such a way as to prevent the glucose isomerizing to aldehyde, or the fructose to alpha-hydroxy-ketone form. This stops it reacting to Benidict's reagent. However sucrose indirectly produces a positive result with Benedict's reagent if heated with dilute hydrochloric acid prior to the test, although after this treatment it is no longer sucrose. ;-)
Why do you add hydrochloric acid to the hydrolysis of sucrose?
HCl In solution. H + and Cl - An easy hydrolysis with this strong acid.
What chemical is used to test for sugars?
Depends on the Sugar: Reducing sugars a normally monosaccharides but there are some disaccharides too like maltose. If its a reducing sugar then you would add Benedicts Reagent (alkaline copper(II) sulphate). You then heat it. if a reducing sugar is present then a precipitate is formed that will be red/orange. A Non-reducing sugar like Sucrose can be tested by first adding benedicts and heating. if no change is present you then add hydrochloric acid to hydrolyse the glycosidic bond. you then add a hydrogen carbonate solution to neutralise the acid. Then repeating the Benedicts and Heating process.
Would glucose solution produce a positive Benedicts test?
No, Benedicts reagent will show positive results if the carbohydrate is a reducing sugar. You will know if it is positive if the sample will turn from blue to green then to orange when you are cooling the solution, which is the last step when you are performing the benedicts test for carbohydrates.
What sugar might be present in a sweet tasting food that tests negative with the Benedicts reagent?
Sucrose. Sucrose is a disaccharide therefore does not have free electrons in the sugar to react with the Benedict reagent. Glucose has free electrons therefore shows positive with the Benedict reagent.
Is a mixture of sucrose and water a solution?
Sucrose is the name for the common sugar compound. A sucrose solution is a solution made of sugar dissolved in water.
Why is hydrochloric acid used when testing for non-reducing sugars?
to hydrolise sucrose solution into a monosaccharide ( glucose and fructose )
Is water and sucrose a solution?
Yes, as long as all of the sucrose is completely dissolved in the water it is a solution.
How do make a percent sucrose solution?
Calculate the weight of sucrose for the desired volume and concentration of the solution.
What solution is sucrose in ethanol?
This is a homogeneous solution.
Why is mitochondria kept in sucrose solution when extracted from cell?
Mitochondria are kept in sucrose solution to keep them metabolically active
