JEE Main 2021 · ChemistryNumerical answerNumerical valueMediumMulti-step

JEE Main 25 February 2021, Shift 1, Chemistry Q59

Question 59 of 90 in this shift, Chemistry question 29 of 30, Section B.

Consider the following chemical reaction.

\mathrm{CH{\equiv}CH}

\xrightarrow[\text{2) CO, HCl, AlCl}_3]{\text{1) Red hot Fe tube, 873 K}}

Product The number of

sp^2

hybridized carbon atom(s) present in the product is ________.

Official answer

NTA final key.

Chapter: Hydrocarbons
Topic: Aromatic Hydrocarbons
Idea tested: Gattermann-Koch Formylation

Same idea in other shifts

Asked 5× in all

8 Apr 2026, Shift 2 · Q72' $x$ ' is the product which is obtained from benzene by reacting it with carbon monoxide and hydrogen chloride in the presence of cuprous…MediumNumerical value
9 Apr 2024, Shift 1 · Q75Identify major product "X" formed in the following reaction : [figure: benzene…EasySingle correctHas a figure
31 Jan 2024, Shift 2 · Q78Identify the name reaction. [reaction: benzene + CO, HCl --(anhydrous AlCl $_3$ /CuCl)--> benzaldehyde (C $_6$ H $_5$ CHO)]EasySingle correctHas a figure
3 Aug 2021, Shift 2 · Q46Which one of the following reagents are not suitable for the preparation of benzaldehyde from benzene?MediumSingle correct

Question text from the official JEE Main paper published by NTA; answer from the final answer key. Chapter, topic and idea tags, difficulty and skill are Lumi’s. Lumi analyses 108 of the 174 JEE Main shifts held from 2017 to 2026.