JEE Main 2021 · ChemistryMultiple choiceOtherMediumMulti-step

JEE Main 26 February 2021, Shift 2, Chemistry Q42

Question 42 of 90 in this shift, Chemistry question 12 of 30, Section A.

[reaction scheme: structure drawn in line-bond form]

\xrightarrow[\text{2) } \mathrm{Cr_2O_3}\text{ , 773 K, 10 - 20 atm}]{\text{1) Zn/HCl}}

Considering the above reaction, the major product among the following is :

The figure, in words

Reactant drawn as a line-bond skeleton: a carbon double-bonded to O (O drawn below) bonded on the right to a two-segment zigzag chain and on the left to a carbon bearing two further chains, a vertical-up two-segment chain and a left-going two-segment chain. Reagents above/below arrow: 1) Zn/HCl, 2) Cr2O3, 773 K, 10-20 atm. Options are each a drawn benzene ring with the printed substituent text.

(1)Benzene ring with a $\mathrm{CH_2CH_3}$ substituentOfficial answer
(2)Benzene ring with a $\mathrm{COCH_2CH_3}$ substituent
(3)Benzene ring with two adjacent $\mathrm{CH_3}$ substituents
(4)Benzene ring with a $\mathrm{CH_2CH_2CH_3}$ substituent

Official answer

Option 1

NTA final key.

Chapter: Aldehydes, Ketones and Carboxylic Acids
Topic: Alkanes and Free Radicals
Idea tested: Aromatization (Reforming) of Alkanes

JEE Main 26 February 2021, Shift 2, Chemistry Q42

Same idea in other shifts