Sign in
Please select an account to continue using cracku.in
↓ →
Join Our JEE Preparation Group
Prep with like-minded aspirants; Get access to free daily tests and study material.
Identify the correct statements.
A. Glucose exists in two anomeric forms.
B. Anomers of glucose differ in configuration at C-1 in cyclic hemiacetal structure.
C. Melting point of $$\alpha$$-anomer of glucose is greater than $$\beta$$-anomer.
D. Specific rotation of $$\alpha$$-anomer is +19° while for $$\beta$$-anomer is +112°.
E. $$\alpha$$ and $$\beta$$-anomers of glucose are prepared by crystallization of saturated glucose solution at 303 K and 371 K respectively.
Choose the correct answer from the options given below:
Glucose exists predominantly in cyclic hemiacetal forms and hence exists as two anomers, namely $$\alpha$$- and $$\beta$$-glucose. Therefore, statement A is correct.
The two anomers differ only in the configuration at the anomeric carbon, i.e., C-1 in the cyclic hemiacetal structure. Therefore, statement B is correct.
The melting point of $$\alpha$$-D-glucose is $$419\ \text{K}$$, whereas that of $$\beta$$-D-glucose is $$423\ \text{K}$$. Hence, the melting point of the $$\alpha$$-anomer is not greater than that of the $$\beta$$-anomer. Therefore, statement C is incorrect.
The specific rotation of pure $$\alpha$$-D-glucose is $$+112^\circ$$, while that of pure $$\beta$$-D-glucose is $$+19^\circ$$. Thus, the values given in statement D are interchanged. Therefore, statement D is incorrect.
The $$\alpha$$-anomer is obtained by crystallization of a saturated glucose solution at $$303\ \text{K}$$, whereas the $$\beta$$-anomer is obtained by crystallization at $$371\ \text{K}$$. Therefore, statement E is correct.
Hence, the correct statements are A, B and E.
Create a FREE account and get:
Educational materials for JEE preparation