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Isomerism · Question 5

JEE Main 2026 (Online) 23rd January Morning ShiftNumericalMedium📈 Topic in 10% papers+4
1

Consider all the structural isomers with molecular formula C5H11Br are separately treated with KOH(aq) to give respective substitution products, without any rearrangement. The number of products which can exhibit optical isomerism from these is .

Answer

3

Solution

C5H11Br has 8 structural isomers; aq. KOH replaces Br by OH (no rearrangement):

(i) CH3CH2CH2CH2CH2Br → pentan-1-ol: no chiral C

(ii) CH3CH2CH2CHBrCH3 → pentan-2-ol: C-2 chiral

(iii) CH3CH2CHBrCH2CH3 → pentan-3-ol: no chiral C

(iv) BrCH2CH(CH3)CH2CH3 → 2-methylbutan-1-ol: C-2 chiral

(v) (CH3)2CBrCH2CH3 → 2-methylbutan-2-ol: no chiral C

(vi) (CH3)2CHCHBrCH3 → 3-methylbutan-2-ol: C-2 chiral

(vii) (CH3)2CHCH2CH2Br → 3-methylbutan-1-ol: no chiral C

(viii) (CH3)3CCH2Br → 2,2-dimethylpropan-1-ol: no chiral C

products that can show optical isomerism = 3

Answer: 3

JEE Main 2026 (Online) 23rd January Morning Shift

Keep practising — Isomerism

2

Identify correct statements from the following : Choose the correct answer from the options given below :

  1. A, B and E only
  2. A, B and C only
  3. C, D and E only
  4. B, C and D only
JEE Main 2026 (Online) 21st January Morning Shift
3

In the light of the above statements, choose the correct answer from the options given below :

  1. Statement I is true but Statement II is false
  2. Both Statement I and Statement II are true
  3. Both Statement I and Statement II are false
  4. Statement I is false but Statement II is true
JEE Main 2026 (Online) 21st January Evening Shift
4

Match List - I with List - II. Choose the correct answer from the options given below :

  1. A-III, B-I, C-IV, D-II
  2. A-II, B-I, C-IV, D-III
  3. A-I, B-IV, C-III, D-II
  4. A-III, B-I, C-II, D-IV
JEE Main 2026 (Online) 21st January Evening Shift
5

Given below are four compounds : (a) n-propyl chloride (b) isopropyl chloride (c) sec-butyl chloride (d) neopentyl chloride Percentage of carbon in the one which exhibits optical isomerism is :

  1. 46
  2. 40
  3. 52
  4. 56
JEE Main 2026 (Online) 21st January Evening Shift
6

The number of optically active products obtained from the complete ozonolysis of the given compound is : [figure]

  1. 4
  2. 0
  3. 2
  4. 1
JEE Main 2025 (Online) 7th April Evening Shift
7

Given below are two statements : In the light of the above statements, choose the most appropriate answer from the options given below :

  1. Both Statement I and Statement II are correct
  2. Statement I is incorrect but Statement II is correct
  3. Both Statement I and Statement II are incorrect
  4. Statement I is correct but Statement II is incorrect
JEE Main 2025 (Online) 7th April Evening Shift
8

Identify the correct statements from the following. Choose the correct answer from the options given below:

  1. B & C Only
  2. C & D Only
  3. A,B & C Only
  4. A & B Only
JEE Main 2025 (Online) 3rd April Morning Shift
9

The total number of structural isomers possible for the substituted benzene derivatives with the molecular formula C9H12 is .

JEE Main 2025 (Online) 3rd April Evening Shift
10

Given below are two statements: In the light of the above statements, choose the correct answer from the options given below:

  1. Statement I is false but Statement II is true
  2. Both Statement I and Statement II are true
  3. Statement I is true but Statement II is false
  4. Both Statement I and Statement II are false
JEE Main 2025 (Online) 28th January Evening Shift

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