Q19 / 75 · JEE Main 2026 (05 April Shift 1) · Chemistry

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:

  • A
    A and B Only
  • B
    B and C Only
  • C
    A, B and D Only
  • Correct answer
    D
    A, B and E Only

Solution

Statement A is correct because glucose exists in two anomeric forms, $\alpha$-D-glucose and $\beta$-D-glucose.

Statement B is correct because the two anomers differ only in the configuration of the hydroxyl group at C$-1$, which is the anomeric carbon in the cyclic hemiacetal structure.

Statement C is incorrect because the melting point of the $\alpha$-anomer is $419$ K, which is less than the melting point of the $\beta$-anomer ($423$ K).

Statement D is incorrect because the specific rotation of the $\alpha$-anomer is $+112^{\circ}$ and that of the $\beta$-anomer is $+19^{\circ}$.

Statement E is correct because the $\alpha$-form is obtained by crystallization from a concentrated solution of glucose at $303$ K, while the $\beta$-form is obtained by crystallization from a hot and saturated aqueous solution at $371$ K.

Thus, statements A, B, and E are correct.

Answer: A, B and E Only

Hence, the correct answer is option: 'D'.

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