0
Benedict's solution is originally blue. Any change in color indicates presence of a reducing sugar. The intensity in color change is proportional to the concentration of the sugar. If there is enough sugar, the color changes from blue to green to yellow to orange to brick red.
Wiki User
∙ 15y ago
Add your answer:
Earn +20 pts
Why is the Benedict test not exclusive to glucose?
The Benedict test will return a positive value for any reducing sugar. It will work with fructose, for example. Benedict solution oxidizes all the reducing sugars such as glucose, galactose and fructose. This implies that a positive result of Benedict's test can be any of the reducing sugars, not necessarily glucose. It will oxidize the carbonyl (which present in all type of sugar classes). So if we get a positive result in the Benedict test, it is not necessarily glucose; it could be galactose or fructose that also a reducing sugar. So Benedict test can't be used to assure glucose.
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 .
Does starch gives positive result for Benedict test?
Starch is made up of repeating glucose units. Though it is a non reducing sugar, its hydrolysis gives out pure glucose, which is known as dextrose. And glucose, as we know, is a reducing sugar and hence would give a positive result in Benedict's test.
Why is the Benedict's test is positive when water starch and HCl keep for 30mins?
benedicts test is positive when water starch and HCL keep for 30 mins because glycosidic linkages between amylose and amylopectin breaks and free ends are available to react with Benedict reagent
Will mannose produce a positive Benedict's test?
Mannose is a monosaccharide (an aldose) with the chemical formula C6H12O6.Being a a monosaccharide mannose react with the Benedict reagent.
Does Benedict test indicate monosaccharides polysaccharides and disaccharides?
The Benedict test is useful for monosaccharides and disaccharides.
Does skim milk test positive with the benedict's test?
yes
What does a negative Benedicts test indicate?
A negative Benedict's test would indicate that there isn't any presence of reducing sugars in that particular substance.
Why is the Benedict test not exclusive to glucose?
The Benedict test will return a positive value for any reducing sugar. It will work with fructose, for example. Benedict solution oxidizes all the reducing sugars such as glucose, galactose and fructose. This implies that a positive result of Benedict's test can be any of the reducing sugars, not necessarily glucose. It will oxidize the carbonyl (which present in all type of sugar classes). So if we get a positive result in the Benedict test, it is not necessarily glucose; it could be galactose or fructose that also a reducing sugar. So Benedict test can't be used to assure glucose.
What is the indicator and color change for a positive test for glucose?
Benedict solution is the chemical indicator for simple sugars.
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 .
Will fructose give a positive benedict's test?
Yes! Fructose is a reducing carbohydrate.
What does a positive Molisch's test on an unknown substance indicate?
A positive Molisch's test result indicates the presence of carbohydrates.
Is it possible for a solution to test positive in Benedict's test and negative in barfoed's test?
No! Its not possible for a solution to test positive for benedict`s and test negative for barfoed `s test as both detect the presence of reducing sugars and the only difference between the two tests is that further confirmation of a mono or disaccharide is done in barfoed ` s test.
Does starch gives positive result for Benedict test?
Starch is made up of repeating glucose units. Though it is a non reducing sugar, its hydrolysis gives out pure glucose, which is known as dextrose. And glucose, as we know, is a reducing sugar and hence would give a positive result in Benedict's test.
What is a positive test for carbohydrates?
These are the carbohydrate tests that would give a positive result on maltose: 1.Molisch test 2. Fehling's Test 3. Benedict's Test 4. Nylander's Test 5. Tollen's Test 6. Seliwanoff's Test 7. Barfoed's Test
Why did a solution of saliva and oats test positive with benedict's test and iodine test if the oats alone tested positive only in the iodine test and the saliva alone was negative for both?
polysaccharides and simple sugar
