What percentage of β-D-(+) glucopyranose is found at equilibrium in the aqueous solution?

Question

What percentage of β-D-(+) glucopyranose is found at equilibrium in the aqueous solution? (A) 50 %  (B) ≈ 100 % (C) 36 % (D) 64 %

Tardigrade Admin · Accepted Answer

Ordinary glucose is α -glucose, with a fresh aqueous solution having specific rotation, [α]D=+111° . On keeping the solution for sometime, α -glucose slowly changes into an equilibrium mixture of α -glucose (36 %) and β- glucose (64 %) and the mixture has specific rotation +52.5° .

Q. What percentage of $β - D - (+)$ glucopyranose is found at equilibrium in the aqueous solution?

$50%$

$\approx 100%$

$36%$

$64%$

Q. What percentage of β−D−(+) glucopyranose is found at equilibrium in the aqueous solution?

50%

≈100%

36%

64%

Ordinary glucose is α -glucose, with a fresh aqueous solution having specific rotation, [α]D​=+111∘. On keeping the solution for sometime, α -glucose slowly changes into an equilibrium mixture of α -glucose (36%) and β− glucose (64%) and the mixture has specific rotation +52.5∘.

Q. What percentage of $β - D - (+)$ glucopyranose is found at equilibrium in the aqueous solution?

$50%$

$\approx 100%$

$36%$

$64%$