Sucrose

Q.

What is a glycosidic linkage?

Q.

The change in optical rotation, with time, of freshly prepared solution of sugar is known as

[CPMT 1982, 85; BHU 1997]

1. Specific rotation

2. Rotatory motion

3. Mutarotation

4. Inversion

Q.

In sucrose, two mono saccharide units are held together by a glycosidic linkage between

1. $C_1$ of $\alpha$-glucose and $C_6$ of $\beta -fructose$

2. $C_1$ of $\alpha$-glucose and $C_2$ of $\beta -fructose$

3. $C_1$ of $\alpha$-glucose and $C_6$ of $\beta -glucose$

4. $C_1$ of $\alpha$-glucose and $C_2$ of $\beta -fructose$

Q.

Hydrolysis of sucrose is called:

1. Esterification

2. Saponification

3. Hydration

4. Inversion

Q. Calculate the specific rotation of invert sugar given that $[\alpha {]}_D=+{52.7}^o$ for D-glucose and $[\alpha {]}_D=-{92.4}^o$ for D-fructose.

1. $+{19.9}^o$
2. $-{19.9}^o$
3. $+{25.0}^o$
4. $-{25.0}^o$

Q.

Which sugar is called invert sugar? Why is it called so?

Q.

Sucrose is dextrorotatory but the mixture obtained after hydrolysis is laevorotatory. Explain.

Q. What are the products of hydrolysis of lactose?

Q.

Which of the following carbohydrates is called milk sugar?

1. Lactose

2. Maltose

3. Glucose

4. Galactose

Q.

What are biomolecules? How are they useful in day-to-day life?

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 assertion is false but reason is true.
5. If both assertion and reason are true and the reason is the correct explanation of the assertion.

Q.

Which of the following pair is C2-epimer?

1. D-Glucose, D-Arabinose

2. D-Glucose, D-Maltose

3. D-Allose, D-Ribose

4. D-Glucose, D-Mannose

Q. Cane sugar on hydrolysis gives

1. Glucose and lactose
2. Only glucose
3. Glucose and maltose
4. Glucose and fructose

Q.

Sucrose when dissolved in water

1. It is converted to glucose and fructose

2. It is converted into glucose and galactose

3. It is converted into 2 molecules of glucose

4. It remains as sucrose

Q.

Sucrose when dissolved in water

1. It is converted to glucose and fructose

2. It is converted into glucose and galactose

3. It is converted into 2 molecules of glucose

4. It remains as sucrose

Q.

Carbohydrates are classified on the basis of their behaviour on hydrolysis and also as reducing or non-reducing sugar. Sucrose is ............. .
(a) monosaccharide (b) disaccharide
(c) reducing suager (d) non-reducing sugar

Q. Which of the following disaccharides will not reduce Tollens reagent?

(IIT-JEE, 2005)

1. Only P
2. Only Q
3. Both P and Q
4. None of these

Q.

What are the hydrolysis products of

(i) Sucrose

(ii) What are the hydrolysis products of lactose?

Q. When heated with acidified $KMn{O}_4$, glycerol gives

1. Oxalic acid
2. formic acid
3. Glyceric Acid
4. Tartaric acid

Q.

Sucrose (can Sugaro) is a disaccharide. One molecule of sucrose on hydrolysis gives............ .
(a) 2 molecules of glucose
(b) 2 molecules of glucose + 1 molecule of fructose
(c) 1 molecule of clucose + 1 molecule of fructose
(d) 2 molecules of fructose

Q. Sucrose (+) on hydrolysis gives a mixture of D-(+) glucose, $[\alpha {]}_D={52.7}^o$ and D-() fructose = 92.4, known as invert sugar. Calculate the rotation of mixture, i.e., invert sugar :

1. $-{19.9}^o$
2. $+{19.9}^o$
3. $-{21.4}^o$
4. $+{21.4}^o$

Q. Freshly prepared solution of cane sugar, under the influence of acid catalyst, undergoes change in optical rotation with laps of time. This phenomenon is called inversion.

1. True
2. False

Q. Which of the following is non-reducing sugar?

1. Starch
2. Galactose
3. Maltose
4. Sucrose

Q. What is essentially the difference between $\alpha$ - glucose and $\beta$ - glucose? What is meant by pyranose structure of glucose?

Q. Cane sugar on hydrolysis gives

1. Glucose and maltose
2. Glucose and lactose
3. Only glucose
4. Glucose and fructose

Q. Write short notes on: Inversion of cane-sugar.

Q. An example of a disaccharide made up of two units of the same monosaccharide is:

1. Sucrose
2. Maltose
3. None of these
4. Lactose

Q. explain the ring opening of disaccharides . Also by ring opening explain why starch is not a reducing sugar

Q. Sucrose (cane sugar) is a disaccharide. One molecule of sucrose on hydrolysis gives:

1. 1 molecule of glucose + 1 molecule of fructose
2. 2 molecules of glucose
3. 2 molecules of fructose
4. 2 molecules of glucose + 1 molecule of fructose

Q.

Which acid produces sugar charcoal from sugar.