answersLogoWhite

0

Yes, fructose is a ketose, for which Seliwanoff's test is most sensitive. Sucrose is neither entirely a ketose nor an aldose, but is a mixture of both. It will react, but more slowly, producing a much lighter pinkish color.

User Avatar

Wiki User

14y ago

What else can I help you with?

Continue Learning about Chemistry

Why sucrose does not give a positive Benedict's test but hydrolyzed sucrose does give a positive beneditcts test?

Sucrose is formed from glucose and fructose.Sucrose is formed from glucose and fructose. Glucose and fructose gives positive test for benedict becuz both of them are reducing sugars whereas sucrose is not a reducing sugar so it gives negative test for benedict. On prolonged heating,sucrose will form glucose and fructose (reducing sugars)which ultimately gives a positive result .


After hydrolysis did sucrose give a positive test with fehlings test why orwhy not?

Sucrose would not give a positive test with Fehling's reagent after hydrolysis because sucrose is a non-reducing sugar. During hydrolysis, sucrose is broken down into its monosaccharide components (glucose and fructose), which are reducing sugars and can react with Fehling's reagent to give a positive test for reducing sugars.


Why does sucrose solution give a negative test with tollen's test?

A positive Tollen's test is given by compounds that have a free aldehyde or ketone functional group. Sucrose is a disaccharide composed of the monosaccharides glucose and fructose. In sucrose, the components glucose and fructose are linked via an ether bond between C1 (carbon with aldehyde group) on the glucosyl subunit and C2 (carbon with ketone group) on the fructosyl unit. The bond is called a glycosidic linkage. In other words, in sucrose there is no free aldehyde or ketone functional group. Hence sucrose will not answer Tollen's test.


How can you determine the difference between NaCl and sucrose?

NaCl and sucrose can be distinguished by their chemical compositions. NaCl is a salt composed of sodium and chloride ions, while sucrose is a disaccharide composed of glucose and fructose molecules. A simple chemical test using silver nitrate can confirm the presence of chloride ions in NaCl, while sucrose will not react with this test.


Why did the enzyme lactase react with lactose but not sucrose?

Because, lactase breaks beta(1-4) glycosidic bonds between a galactose and a glucose, while sucrose molecule is formed by a dimer of a glucose and a fructose linked by an alpha(1-2) glycosidic bond.

Related Questions

Why sucrose does not give a positive Benedict's test but hydrolyzed sucrose does give a positive beneditcts test?

Sucrose is formed from glucose and fructose.Sucrose is formed from glucose and fructose. Glucose and fructose gives positive test for benedict becuz both of them are reducing sugars whereas sucrose is not a reducing sugar so it gives negative test for benedict. On prolonged heating,sucrose will form glucose and fructose (reducing sugars)which ultimately gives a positive result .


How do you distinguish glucose and fructose?

Glucose is an aldose whereas fructose in a ketose. There is a simple qualitative test for distinguishing between D-Glucose and D-Fructose.


Which of the following pairs give positive toollens test-hexanal,acetophenone and fructose,sucrose?

The simple sugars will not react with the test because they are not aldehydes.


After hydrolysis did sucrose give a positive test with fehlings test why orwhy not?

Sucrose would not give a positive test with Fehling's reagent after hydrolysis because sucrose is a non-reducing sugar. During hydrolysis, sucrose is broken down into its monosaccharide components (glucose and fructose), which are reducing sugars and can react with Fehling's reagent to give a positive test for reducing sugars.


Why does sucrose solution give a negative test with tollen's test?

A positive Tollen's test is given by compounds that have a free aldehyde or ketone functional group. Sucrose is a disaccharide composed of the monosaccharides glucose and fructose. In sucrose, the components glucose and fructose are linked via an ether bond between C1 (carbon with aldehyde group) on the glucosyl subunit and C2 (carbon with ketone group) on the fructosyl unit. The bond is called a glycosidic linkage. In other words, in sucrose there is no free aldehyde or ketone functional group. Hence sucrose will not answer Tollen's test.


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. ;-)


How can you determine the difference between NaCl and sucrose?

NaCl and sucrose can be distinguished by their chemical compositions. NaCl is a salt composed of sodium and chloride ions, while sucrose is a disaccharide composed of glucose and fructose molecules. A simple chemical test using silver nitrate can confirm the presence of chloride ions in NaCl, while sucrose will not react with this test.


What test can be used to identify the presence of the fructose?

Seliwanoff's test is used to differentiate aldose [glucose] from ketose [fructose]. Seliwanoff's reagent is composed of resorcinol and HCl. When heated with concentrated hydrochloric acid, the polysaccharides and oligosaccharides hydrolyze to yield monosaccharides. Then, resorcinol reacts in the dehydrated ketose to form oxymethylfurfurol produce a deep cherry red color [red precipitate]. Aldoses produces a faint pink colored solution.


Why did the enzyme lactase react with lactose but not sucrose?

Because, lactase breaks beta(1-4) glycosidic bonds between a galactose and a glucose, while sucrose molecule is formed by a dimer of a glucose and a fructose linked by an alpha(1-2) glycosidic bond.


List of carbohydrates that is positive to Molisch Benedicts Barfoeds Seliwanoffs Bials and Fermentation tests?

Glucose, fructose, maltose, sucrose, lactose, and starch are carbohydrates that would likely test positive in Molisch, Benedict's, Barfoed's, Seliwanoff's, Bial's, and fermentation tests. These carbohydrates are commonly used in biochemical testing due to their distinct reactivity with the specific reagents in each test.


Why the majority said that sucrose is a ketose sugar?

The majority would be incorrect. Sucrose is not considered an aldose or a ketose, because it is a disaccharide made from glucose (an aldose) and fructose (a ketose). So, it has both properties within its structure. It is a non-reducing sugar.It is possible that many say sucrose is a ketose because sucrose will fail the Benedict's test, which is designed to detect aldoses.


Inulin is a polysaccharide composed entirely of fructose units.Which test be used to identify the presence of fructose?

The presence of fructose can be identified using a Benedict's test. Benedict's reagent can detect reducing sugars like fructose by forming a colored precipitate when reacted with the sugar in a heated solution. This forms a qualitative test to confirm the presence of fructose.