Question

Which of the following statements is not true about glucose?

• A. It is an aldohexose.
• B. It is present in furanose form.
• C. On heating with $HI$, it forms $n-$hexane.
• D. It does not give $2,4-DNP$ test.

Answer 1

The correct option is B It is present in furanose form.

Analysing the options

Option (A):

Glucose is a monosaccharide and also aldohexose because it consists of six carbon atoms and an aldehyde group.

Option (B):

On heating glucose with $HI$, it gets reduced to form $n-$hexane.



Option (C):

Glucose is present in the pyranose form. Its cyclic structure is a six-membered ring similar to the organic compound pyran.




Option (D):

Glucose doesn't react with Schiff's reagent & $2,4DNP$ reagent despite having an aldehyde group because there is no free aldehyde group present in the cyclic form as it forms hemiacetal. Thus, it does not give $2,4-DNP$ test.

So, the correct answer is option (C).