Tests for Carbohydrates

Q.

Why is glucose a 'reducing sugar'?

1. it has a ketone group

2. it contains an aldehyde group

3. it is a monosaccharide

4. glucose is not a reducing sugar

Q. Assertion : Sucrose is a non-reducing sugar.

Reason : It has a glycosidic linkage.

1. If both assertion and reason are true but reason is not the correct explanation of the assertion.
2. If assertion is true but reason is false.
3. If the assertion and reason both are false.
4. If both assertion and reason are true and the reason is the correct explanation of the assertion.

Q. Fehling's solution can detect ___.

1. Starch
2. Fat
3. Glucose
4. Sucrose

Q. Molisch's test is done for the detection of ________.

1. Alkaloid
2. Alkyl halide
3. Carbohydrate
4. Fat

Q. Benedict’s test is conducted to confirm the presence of :

1. polysaccharides like starch
2. lipids
3. reducing sugars
4. proteins

Q. Which one of these is a reducing sugar ?

1. Galactose
2. Gluconic acid
3. Sucrose
4. -methyl galactoside.

Q. Fehling's test is not positive in case of _________.

1. Glucose
2. Fructose
3. Lactose
4. Sucrose

Q. On heating glucose with Fehling's solution, we get a precipitate whose colour is _______.

1. Red
2. Yellow
3. White
4. Black

Q. Glucose gives silver mirror as a result, with Tollen's reagent. It shows the presence of

1. An alcoholic group
2. An aldehydic group
3. An acidic group
4. A ketonic group

Q. The brick red precipitate formed in Fehling's and Benedict's test is due to the

1. Reduction of Cu²⁺ ions to Cu⁺ ions

2. presence of sulphur ions in the reagents

3. presence of non-reducing sugars

4. Formation of Cu(I)oxide