Atomos Test Generator Free PYQs ExamsMy practice Log in / Sign up free

Hydrocarbons

JEE Main 2026 (Online) 28th January Morning ShiftMCQMedium📈 Topic in 24% papers+4−1
Ques. 1JEE Main 2026, 28 January (Morning Shift)

Given below are two statements for the following reaction sequence. [figure] 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. Statement I is false but Statement II is true
  4. Both Statement I and Statement II are false

Answer

(2) Both Statement I and Statement II are true

Solution

X (C3H6Cl2, e.g. CH3CCl2CH3) undergoes double dehydrohalogenation with excess NaNH2:

CH3CCl2CH3 excess NaNH2 CH3-C CH (propyne, Y)

Z: hydration of propyne with dil. H2SO4 / Hg2+ follows Markovnikov's rule:

CH3-C CH + H2O Hg2+, H+ CH3COCH3 (propanone, Z)

Z is a methyl ketone (CH3CO-), so it gives the iodoform test: with NaOI it forms a yellow precipitate of CHI3. Statement I is true.

Q: as per NCERT, alkynes passed through a red hot iron tube at 873 K undergo cyclic polymerisation; three molecules of propyne give mesitylene (1,3,5-trimethylbenzene), C9H12:

[figure]

Aromatic H = 3 (one on each free ring carbon), aliphatic H = 9 (three CH3 groups)

aromatic : aliphatic = 3 : 9 = 1 : 3. Statement II is true.

Answer: (2)

Keep practising — Hydrocarbons

Ques. 2JEE Main 2026, 28 January (Morning Shift)

Ph-CH=CH2 [HBr](PhCOO)2 Product Consider the above reaction Identify the correct statements. Choose the correct answer from the options given below :

  1. A & E Only
  2. A, B & D Only
  3. A, C & E Only
  4. C, D & E Only
Ques. 3JEE Main 2026, 28 January (Evening Shift)

The reactions which produce alcohol as the product are : Choose the correct answer from the options given below :

  1. B, D and E Only
  2. A and D Only
  3. A, C and E Only
  4. C and D Only
Ques. 4JEE Main 2026, 23 January (Morning Shift)

Consider the following compounds : [figure] Arrange these compounds in the increasing order of reactivity with nitrating mixture.

  1. c < b < a
  2. b < c < a
  3. c < a < b
  4. b < a < c
Ques. 5JEE Main 2026, 23 January (Morning Shift)

But-2-yne and hydrogen (one mole each) are separately treated with (i) Pd/C and (ii) Na/ liq. NH3 to give the products X and Y respectively. [figure] Identify the incorrect statements. Choose the correct answer from the options given below :

  1. B and D Only
  2. A and C Only
  3. A and B Only
  4. B and C Only
Ques. 6JEE Main 2026, 23 January (Evening Shift)

[figure] Identify (P)

  1. [figure]
  2. [figure]
  3. [figure]
  4. [figure]
Ques. 7JEE Main 2026, 22 January (Morning Shift)

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

  1. Statement I is incorrect but Statement II is correct
  2. Both Statement I and Statement II are correct
  3. Both Statement I and Statement II are incorrect
  4. Statement I is correct but Statement II is incorrect
Ques. 8JEE Main 2026, 22 January (Morning Shift)

The cycloalkene (X) on bromination consumes one mole of bromine per mole of (X) and gives the product (Y) in which C : Br ratio is 3:1. The percentage of bromine in the product (Y) is %. (Nearest integer) (Given : molar mass in g mol-1 H : 1, C : 12, O : 16, Br : 80)

Ques. 9JEE Main 2026, 22 January (Evening Shift)

Consider the following reaction : [figure] The product Y formed is :

  1. 2-methylhex-3-yne
  2. 5-methylhex-2-yne
  3. Isopropylbut-1-yne
  4. 2-methylhex-2-yne
Ques. 10JEE Main 2026, 22 January (Evening Shift)

The dibromo compound [P] (molecular formula: C9H10Br2) when heated with excess sodamide followed by treatment with dilute HCl gives [Q]. On warming [Q] with mercuric sulphate and dilute sulphuric acid yields [R] which gives positive Iodoform test but negative Tollens' test. The compound [P] is :

  1. [figure]
  2. [figure]
  3. [figure]
  4. [figure]
Ques. 11JEE Main 2026, 21 January (Morning Shift)

Identify A in the following reaction. [figure]

  1. [figure]
  2. [figure]
  3. [figure]
  4. [figure]

All Hydrocarbons PYQs →

PDFDownload Hydrocarbons PYQs as PDF Free, with answer key and a QR code to every solution — print it or study offline⬇
All JEE Main Chemistry chapters