JEE Main · 2018 · 08 Apr 2018 · Offline · Biomolecules

Glucose on prolonged heating with HI gives :

(A)6-iodohexanal
(B)n-Hexane✓ Correct
(C)1-Hexene
(D)Hexanoic acid

Answer: (B)

Solution

Prolonged heating with

HI

is an exhaustive reduction in which every

- OH

group and the aldehyde carbon are stripped of oxygen and replaced by hydrogen. Glucose,

C X_{6} H X_{12} O X_{6}

, is thereby reduced all the way to the straight-chain hydrocarbon n-hexane, following

C X_{6} H X_{12} O X_{6} + 12 HI C X_{6} H X_{14} + 6 H X_{2} O + 6 I X_{2}

JEE Main · 2018 · 08 Apr 2018 · Offline · Single correct option

Practise more: all JEE Main PYQs on Biomolecules →

More JEE Main questions on Biomolecules

Identify the correct statements.

A. Arginine and Tryptophan are essential amino acids.
B. Histidine does not contain heterocyclic ring in its structure.
C. Proline is a six membered cyclic ring amino acid.
D. Glycine does not have chiral centre.
E. Cysteine has characteristic fe …
JEE Main 2026View solution →
Given below are two statements:

Statement I: Sucrose is dextrorotatory. However sucrose upon hydrolysis gives a solution having mixture of products. This solution shows laevorotation.

Statement II : Hydrolysis of sucrose gives glucose and fructose. Since the laevorotation of gl …
JEE Main 2026View solution →
The correct statements are:
A. Activation energy for enzyme catalysed hydrolysis of sucrose is lower than that of acid catalysed hydrolysis.
B. During denaturation, secondary and tertiary structures of a protein are destroyed but primary structure remains intact.
C. Nucleotides a …
JEE Main 2026View solution →
Match List-I with List-II.

List-I
Reaction of glucose with
A. Hydroxylamine
B. $Br_{2}$ water
C. Excess acetic anhydride
D. Concentrated $HNO_{3}$

List-II
Product formed
I. Glouconic acid
II. Glucose pentacetate
III. Saccharic acid
IV. Glucoxime

Choose th …
JEE Main 2026View solution →
Both human DNA and RNA are chiral molecules. The chirality in DNA and RNA arises due to the presence of
JEE Main 2026View solution →
The number of possible tripeptides formed involving alanine (ala), glycine (gly) and valine (val), where no amino acid has been used more than once is :
JEE Main 2026View solution →