Sign in
12thPass logo
New chatPYQ LibraryDoubtsRank report
Sign in to see Recents

Your guest activity stays on this device

Sign in to save progress →
Sign in

Compounds Containing Nitrogen question

2022 · 28 Jul · Shift 1 · Q11
Guest · filters and generic practice availableBrowsing as a guest · PYQ filters and generic practice are available. Sign in only for personalised features and saved progress.
  1. PYQ Library
  2. /JEE Main
  3. /Chemistry
  4. /Compounds Containing Nitrogen
  5. /2022 · 28 Jul · Shift 1 · Q11

Compounds Containing Nitrogen question

2022 · 28 Jul · Shift 1 · Q11

JEE MainChemistryCompounds Containing NitrogenMCQ+4 / −1
Identify the correct statement for the below given transformation. JEE Main 2022 (Online) 28th July Morning Shift Chemistry - Compounds Containing Nitrogen Question 89 English
  1. A
    A−CH3CH2CH=CH−CH3, B−CH3CH2CH2CH=CH2\mathrm{A}-\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CH}=\mathrm{CH}-\mathrm{CH}_{3}, \mathrm{~B}-\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{CH}=\mathrm{CH}_{2}A−CH3​CH2​CH=CH−CH3​, B−CH3​CH2​CH2​CH=CH2​, Saytzeff products
  2. B
    A−CH3CH2CH=CH−CH3\mathrm{A}-\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CH}=\mathrm{CH}-\mathrm{CH}_{3}A−CH3​CH2​CH=CH−CH3​, B −CH3CH2CH2CH=CH2-\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{CH}=\mathrm{CH}_{2}−CH3​CH2​CH2​CH=CH2​, Hofmann products
  3. C
    A−CH3CH2CH2CH=CH2, B−CH3CH2CH=CHCH3\mathrm{A}-\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{CH}=\mathrm{CH}_{2}, \mathrm{~B}-\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CH}=\mathrm{CHCH}_{3}A−CH3​CH2​CH2​CH=CH2​, B−CH3​CH2​CH=CHCH3​, Hofmann products
  4. D
    A−CH3CH2CH2CH=CH2, B−CH3CH2CH=CHCH3\mathrm{A}-\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{CH}=\mathrm{CH}_{2}, \mathrm{~B}-\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CH}=\mathrm{CHCH}_{3}A−CH3​CH2​CH2​CH=CH2​, B−CH3​CH2​CH=CHCH3​, Saytzeff products
View written solutionFree

Correct answer: C

  1. Reaction type involved

The question is from compounds containing nitrogen, so the transformation is the typical exhaustive methylation followed by elimination of an amine, i.e. Hofmann elimination.

In Hofmann elimination, a quaternary ammonium hydroxide on heating undergoes β\betaβ-elimination to give an alkene.

A very important rule is:

Hofmann elimination gives the less substituted alkene as the major product.\text{Hofmann elimination gives the less substituted alkene as the major product.}Hofmann elimination gives the less substituted alkene as the major product.

So the products formed are called Hofmann products, not Saytzeff products.


  1. Compare the two possible alkenes

For a pentyl skeleton, the two possible elimination products shown in the options are:

  • CH3CH2CH=CHCH3\mathrm{CH_3CH_2CH=CHCH_3}CH3​CH2​CH=CHCH3​ = pent-2-ene
  • CH3CH2CH2CH=CH2\mathrm{CH_3CH_2CH_2CH=CH_2}CH3​CH2​CH2​CH=CH2​ = pent-1-ene

Now,

  • pent-2-ene is the more substituted alkene
  • pent-1-ene is the less substituted alkene

Therefore, under Hofmann elimination:

CH3CH2CH2CH=CH2\mathrm{CH_3CH_2CH_2CH=CH_2}CH3​CH2​CH2​CH=CH2​

is the Hofmann product.


  1. Assign A and B

From the given options, the correct statement must identify:

  • one product as CH3CH2CH2CH=CH2\mathrm{CH_3CH_2CH_2CH=CH_2}CH3​CH2​CH2​CH=CH2​
  • the other as CH3CH2CH=CHCH3\mathrm{CH_3CH_2CH=CHCH_3}CH3​CH2​CH=CHCH3​
  • and classify them as Hofmann products

Option C states exactly this ordering:

  • A=CH3CH2CH2CH=CH2A = \mathrm{CH_3CH_2CH_2CH=CH_2}A=CH3​CH2​CH2​CH=CH2​
  • B=CH3CH2CH=CHCH3B = \mathrm{CH_3CH_2CH=CHCH_3}B=CH3​CH2​CH=CHCH3​
  • products are Hofmann products

This matches the rule that the less substituted alkene is favored.


  1. Check all options
  • A: calls them Saytzeff products → incorrect
  • B: structures ordered differently and also inconsistent with Hofmann assignment → incorrect
  • C: less substituted alkene assigned correctly, classified as Hofmann → correct
  • D: same structures as C but calls them Saytzeff products → incorrect

  1. Final answer

C\boxed{\text{C}}C​

The elimination is Hofmann elimination, giving the less substituted alkene preferentially:

A=CH3CH2CH2CH=CH2,B=CH3CH2CH=CHCH3A = \mathrm{CH_3CH_2CH_2CH=CH_2}, \quad B = \mathrm{CH_3CH_2CH=CHCH_3}A=CH3​CH2​CH2​CH=CH2​,B=CH3​CH2​CH=CHCH3​

PreviousNext

More from Compounds Containing Nitrogen

  • Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R Assertion A : Aniline on nitration yields ortho, meta & para nitro derivatives of aniline. Reason R :…2022 · MCQ
  • Identify the major product formed in the following sequence of reactions: Includes diagram2022 · MCQ
  • A primary aliphatic amine on reaction with nitrous acid in cold (273 K) and there after raising temperature of reaction mixture to room temperature (298 K), gives a/an2022 · MCQ
  • With respect to the following reaction, consider the given statements : (A) o-Nitroaniline and p-nitroaniline are the predominant products. (B) p-Nitroaniline and m-nitroaniline are the predominant products. (C) HNO3​ acts as an acid.… Includes diagram2022 · MCQ
  • Consider the above reaction, the compound 'A' is : Includes diagram2022 · MCQ
  • Which among the following represent reagent 'A'? Includes diagram2022 · MCQ
  • Consider the following reaction sequence: The product 'B' is : Includes diagram2022 · MCQ
  • Which among the following is the strongest Bronsted base?2022 · MCQ