Polymers — JEE Advanced · 2024 · 26 May 2024 · Paper 2 Question with Solution

An organic compound P with molecular formula

C_{9} H_{18} O_{2}

decolorizes bromine water and also shows positive iodoform test. P on ozonolysis followed by treatment with

H_{2} O_{2}

gives Q and R. While compound Q shows positive iodoform test, compound

R

does not give positive iodoform test.

Q

and

R

on oxidation with pyridinium chlorochromate (PCC) followed by heating give

S

and

T

, respectively. Both

S

and

T

show positive iodoform test.

Complete copolymerization of 500 moles of

Q

and 500 moles of

R

gives one mole of a single acyclic copolymer U.
[Given, atomic mass :

H = 1, C = 12, O = 16

]

Sum of number of oxygen atoms in

S

and

T

is ____.

Answer: 2

Solution

From the given information:

P has formula $C_{9} H_{18} O_{2}$ , decolorizes $Br_{2}$ (unsaturation), and gives positive iodoform test ( $CH_{3} CO -$ or $CH_{3} CH (OH) -$ ).
Ozonolysis gives Q and R, where Q gives iodoform test but R does not.
PCC oxidation followed by heating converts Q → S and R → T, both giving iodoform test.

P is likely a β-hydroxy unsaturated ester. Ozonolysis gives:

PCC oxidation + heating:

Total oxygen atoms in S and T = 1 + 1 = 2

JEE Advanced · 2024 · 26 May 2024 · Paper 2 · Numerical answer