question_answer

In aqueous solution glucose remains as

A)  only in open chain form

B)  only in pyranose form

C)  only in furanose form

D)  in all three forms in equilibrium

Correct Answer: B

Solution :

                 In aqueous solution, the aldohexoses like glucose exist predominantly in pyranose form. Remember! In aqueous solution, glucose consists of about 0.003% aldehyde, and a trace of hydrate; the rest, more than 99.99% is cyclic hemiacetols. Note Ketohexose like fructose exist in furanose form.