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Why does sucrose solution give a negative test with tollen's test?
Wiki User
∙ 11y ago
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.
Wiki User
∙ 11y ago
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Why might a substance taste sweet but give a negative reaction with the Benedict's solution?
It is because the sugar in science is very different from the sugar we know. The sugar we know is sweet thing but in science it has to do with many things like sucrose and such
How do you differentiate between glucose solution and sucrose solution?
One way is by polarimeter; glucose and sucrose rotate polarized light in opposite directions. This is assuming your materials are of biological origin and therefore consist of the D-forms of both; if they're synthetic, then all bets are off.
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 .
Why fructose gives positive tollen reagent test?
Only aldehydes give a positive Tollens test. However, under the strongly basic conditions of the test, alpha-hydroxy ketones can isomerize to aldehydes, so they will also give a positive Tollens test. Fructose is an alpha-hydroxy ketone.
After hydrolysis did sucrose give a positive test with fehlings test why orwhy not?
After hydrolysis sucrose did give a positive test. It reduces sugar that has hemiketal and hemiaetal in it.
Why might a substance taste sweet but give a negative reaction with the Benedict's solution?
It is because the sugar in science is very different from the sugar we know. The sugar we know is sweet thing but in science it has to do with many things like sucrose and such
How do you differentiate between glucose solution and sucrose solution?
One way is by polarimeter; glucose and sucrose rotate polarized light in opposite directions. This is assuming your materials are of biological origin and therefore consist of the D-forms of both; if they're synthetic, then all bets are off.
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 .
Give an example of disaccharides?
Sucrose
Why fructose gives positive tollen reagent test?
Only aldehydes give a positive Tollens test. However, under the strongly basic conditions of the test, alpha-hydroxy ketones can isomerize to aldehydes, so they will also give a positive Tollens test. Fructose is an alpha-hydroxy ketone.
After hydrolysis did sucrose give a positive test with fehlings test why orwhy not?
After hydrolysis sucrose did give a positive test. It reduces sugar that has hemiketal and hemiaetal in it.
Can sucrose cause ADD?
it can give you a sugar rush...
Which disaccharide does hydrolysis give glucose and fructose?
sucrose
What substances give a positive tollens test?
When adding the aldehyde or ketone to Tollens' reagent, the test tube is put in a warm water bath. If the reactant under test is an aldehyde, Tollens' test results in a silver mirror. If the reactant is a ketone, it will not react because a ketone cannot be oxidized easily. A ketone has no available hydrogen atom on the carbonyl carbon that can be oxidized - unlike an aldehyde, which has this hydrogen atom.
What is the principles of tollen's test?
The principle of Tollens' test is to distinguish between aldehydes and ketones. It involves the reduction of silver ions to silver metal in the presence of aldehydes, which results in the formation of a silver mirror on the inner surface of the test tube. Ketones do not give a positive Tollens' test because they do not undergo this reaction with silver ions.
What is a negitaive times a positive?
A negative number times a positive number will give you a negative product.A negative number times a positive number will give you a negative product.A negative number times a positive number will give you a negative product.A negative number times a positive number will give you a negative product.
What happen when you react sugar like glucose and fructose with tollen' s reagent and the Fehlings solution?
Glucose oxidizes very quickly, and creates a silver mirror layer between the glucose solution and the Tollens' reagent. This is because of how the ketose reacts and reduces the silver molecules in Tollen's reagent.
