Hydrocarbons

11 lessons

Topic index in NCERT order

11 of 11 lessons by the NCERT chapter they teach from, in book order. The page is the first printed page of your NCERT book the lesson cites; PYQs are the past NEET questions on that topic.

Class 11 Chemistry, Chapter 9

  1. Hydrocarbon Classificationp. 2963 PYQs
  2. Alkane Halogenation Mechanismp. 3031 PYQ
  3. Alkane Conformationsp. 3051 PYQ
  4. Electrophilic Additionp. 3110 PYQs
  5. Markovnikov Peroxidep. 3111 PYQ
  6. Ozonolysisp. 3132 PYQs
  7. Alkyne Acidic Characterp. 3160 PYQs
  8. Benzene Aromaticityp. 3213 PYQs
  9. Electrophilic Aromatic Substitutionp. 3220 PYQs
  10. Friedel Craftsp. 3220 PYQs
  11. Directive Influencep. 3240 PYQs
01

Alkane Conformations

8 MCQs1 PYQsWorked example
Easy Recall (3)Direct Application (3)Concept Trap (2)
02

Alkane Halogenation Mechanism

8 MCQs1 PYQs6 revision cardsWorked example
Easy Recall (3)Direct Application (3)Concept Trap (1)Calculation (1)
03

Alkyne Acidic Character

8 MCQsWorked example
Easy Recall (3)Direct Application (3)Concept Trap (2)
04

Benzene Aromaticity

8 MCQs3 PYQsWorked example
Easy Recall (3)Direct Application (3)Concept Trap (2)
05

Directive Influence

8 MCQsWorked example
Easy Recall (3)Direct Application (3)Concept Trap (1)Calculation (1)
06

Electrophilic Addition

8 MCQs2 revision cardsWorked example
Easy Recall (3)Direct Application (3)Concept Trap (1)Calculation (1)
07

Electrophilic Aromatic Substitution

8 MCQsWorked example
Easy Recall (3)Direct Application (3)Concept Trap (1)Calculation (1)
08

Friedel Crafts

8 MCQsWorked example
Easy Recall (3)Direct Application (3)Concept Trap (1)Calculation (1)
09

Hydrocarbon Classification

8 MCQs3 PYQsWorked example
Easy Recall (3)Direct Application (3)Concept Trap (1)Calculation (1)
10

Markovnikov Peroxide

8 MCQs1 PYQs9 revision cardsWorked example
Easy Recall (3)Direct Application (3)Concept Trap (1)Calculation (1)
11

Ozonolysis

8 MCQs2 PYQsWorked example
Easy Recall (3)Direct Application (3)Concept Trap (1)Calculation (1)

Past-paper questions from this unit

11 questions from NEET 2020, 2021, 2022, 2023, 2024, 2025, 2026. Answers verified against NTA official keys.

By year in our set: 2020 (2) · 2021 (2) · 2022 (2) · 2023 (2) · 2024 (1) · 2025 (1) · 2026 (1)

Lesson: Benzene Aromaticity

Lesson: Hydrocarbon Classification

NEET 2024Revised key

Given below are two statements: Statement I : The boiling point of three isomeric pentanes follows the order n-pentane > isopentane > neopentane Statement II : When branching increases, the molecule attains a shape of sphere. This results in smaller surface area for contact, due to which the intermolecular forces between the spherical molecules are weak, thereby lowering the boiling point. In the light of the above statements, choose the most appropriate answer from the options given below:

1Both Statement I and Statement II are correct.
2Both Statement I and Statement II are incorrect.
3Statement I is correct but Statement II is incorrect.
4Statement I is incorrect but Statement II is correct.
NTA Answer: Option 1(revised_final)

Report an error · Every fix is public: corrections log

Lesson: Benzene Aromaticity

Lesson: Markovnikov Peroxide

Lesson: Ozonolysis

Exam traps and common mistakes in this unit

Lesson: Electrophilic Addition

Trap

Markovnikov reverses with peroxide

Category: Organic Reaction Conditions

HBr addition to alkene: WITHOUT peroxide → Markovnikov (H to C with more H). WITH peroxide (Kharasch effect) → anti-Markovnikov (radical mechanism). Specific to HBr only — not HCl, HI.

When it triggers

Question gives HX addition to alkene with explicit peroxide condition or hints (e.g. ROOR, light).

How to avoid

Without peroxide: ionic mechanism, carbocation stability → Markovnikov. With peroxide: radical mechanism, radical stability → anti-Markovnikov. Effect ONLY for HBr (HCl too strong, HI too weak).

Lesson: Hydrocarbon Classification

Trap

Solvent changes product distribution

Category: Organic Reaction Conditions

Same starting materials give different products depending on solvent. Polar protic (water, alcohols): SN1/E1 favoured. Polar aprotic (DMSO, DMF): SN2 favoured. Affects substitution vs elimination.

When it triggers

Question contrasts product when solvent is changed; or specifies solvent type.

How to avoid

Polar protic stabilises carbocation → SN1/E1 (3° preferred). Polar aprotic doesn't solvate nucleophile → strong SN2 nucleophile (1°/2° preferred). Bulky base (t-BuOK) favours E2 over SN2.

Lesson: Directive Influence

Mistake

Confuses ortho/para directors with meta directors.

Root cause: concept gap

Correction

o,p-directors (activators except halogens): -OH, -OR, -NH₂, -NHR, alkyl. m-directors (deactivators): -NO₂, -CN, -COOH, -CHO. Halogens: o,p-directors but DEACTIVATORS.

Lesson: Markovnikov Peroxide

Formulas in this unit

Lesson: Electrophilic Addition

Markovnikov's rule (and anti-Markovnikov)

Without peroxide: ionic mechanism — H goes to carbon with MORE hydrogens (carbocation stability rule). With peroxide (HBr only, Kharasch): radical mechanism — anti-Markovnikov.

SymbolQuantitySI Unit
H,Xadded atoms-

Valid when

  • Asymmetric alkene
  • H-X with X = Cl, Br, I
  • Without peroxide for Markovnikov

NEET question patterns in this unit

Lesson: Directive Influence

Lesson: Electrophilic Addition

Questions about this unit

What does Hydrocarbons cover for NEET Chemistry?
11 lessons: Alkane Conformations, Alkane Halogenation Mechanism, Alkyne Acidic Character, Benzene Aromaticity, Directive Influence, Electrophilic Addition, Electrophilic Aromatic Substitution, Friedel Crafts, Hydrocarbon Classification, Markovnikov Peroxide and Ozonolysis.
How often has Hydrocarbons come up in NEET past papers?
Our set of verified past papers has 11 questions from this unit, from NEET 2020, 2021, 2022, 2023, 2024, 2025 and 2026. Each is answered against the official NTA key.
Is the Hydrocarbons material free?
Yes. All 11 lessons and 88 practice questions are free, with no login needed.