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Saturday, 31 October

JEE Main 2021 · ChemistryMultiple choiceSingle correctEasyConceptual

JEE Main 24 February 2021, Shift 2, Chemistry Q42

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

The diazonium salt of which of the following compounds will form a coloured dye on reaction with β\beta-Naphthol in NaOH ?

The figure, in words

Each option is a drawn structure: a benzene ring (drawn with an inner circle) with a single substituent as described in the option text.
  1. (1)[figure: benzene ring with an NH2\mathrm{NH_2} group attached]Official answer
  2. (2)[figure: benzene ring with a CH2NH2\mathrm{CH_2NH_2} group attached]
  3. (3)[figure: benzene ring with an NH−CH3\mathrm{NH-CH_3} group attached]
  4. (4)[figure: benzene ring with an N atom attached, the N bearing two CH3\mathrm{CH_3} groups]

Official answer

Option 1

NTA final key.

Chapter
Amines
Topic
Diazonium Salts
Idea tested
Azo Coupling Reactions

Same idea in other shifts

Asked 11× in all
  1. 2 Apr 2025, Shift 2 · Q69When a concentrated solution of sulphanilic acid and 1-naphthylamine is treated with nitrous acid (273 K) and acidified with acetic acid,…MediumSingle correct
  2. 6 Apr 2024, Shift 1 · Q909.3 g of pure aniline upon diazotisation followed by coupling with phenol gives an orange dye. The mass of orange dye produced (assume…MediumNumerical value
  3. 30 Jan 2024, Shift 1 · Q80Following is a confirmatory test for aromatic primary amines. Identify reagent (A) and (B). [Scheme: aniline (C6H5NH2\mathrm{C_6H_5NH_2})…EasyDiagram basedHas a figure
  4. 30 Jan 2024, Shift 2 · Q79The products A and B formed in the following reaction scheme are respectively Benzene…EasyDiagram basedHas a figure
  5. 31 Jan 2024, Shift 2 · Q80The azo-dye (Y) formed in the following reactions is Sulphanilic acid + NaNO2\mathrm{NaNO_2} + CH3COOH\mathrm{CH_3COOH} →\rightarrow X. X +…MediumDiagram basedHas a figure
  6. 15 Apr 2023, Shift 1 · Q77Consider the following sequence of reactions: [figure: aniline (C6H5NH2\mathrm{C_6H_5NH_2})…EasyDiagram basedHas a figure
  7. 29 Jul 2022, Shift 1 · Q77[figure: benzenediazonium chloride (benzene ring bearing N+≡NCl−\mathrm{N^{+}\equiv NCl^{-}}) + 'A' →NaOH\xrightarrow{\mathrm{NaOH}} Product…EasyDiagram basedHas a figure
  8. 3 Aug 2021, Shift 1 · Q46Sulphanilic acid on diazotisation and then reaction with N,N–dimethylaniline gives which of the following? Mark if their common name is…MediumDiagram basedHas a figure

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. This question needs a figure we do not reproduce; it is described in words above. Lumi analyses 108 of the 174 JEE Main shifts held from 2017 to 2026.