If you are wondering how to study Hydrocarbons for JEE, start with one number. JEE Main asked 59 questions from this chapter across 2024, 2025 and 2026, and 16 of them were about alkenes: addition with and against Markovnikov's rule, ozonolysis and stability. Another 11 were multi-step conversions that pass through an alkene or an alkyne. JEE Advanced asked 20 questions from the chapter between 2015 and 2026. This guide breaks all of them down, based on the papers conducted by the National Testing Agency (jeemain.nta.ac.in) for JEE Main and the JEE Advanced papers from 2015 to 2026.
We went through every one of those questions and tagged it by the class of compound it tests: alkanes, alkenes, alkynes, aromatic hydrocarbons, isomer counting, or a multi-step conversion that crosses classes. The tables below show exactly where the marks come from, and the rest of the guide shows how to win them.
Hydrocarbons is the first real reactions chapter of Organic Chemistry, and the papers treat it that way. Most questions give you a reagent and ask what it does. If you know the dozen key reagents and the one rule each follows, the chapter is predictable.
It is asked in almost every paper. JEE Main had 18 questions from this chapter in 2024, 20 in 2025 and 21 in 2026. That is 3.0%, 4.2% and 4.4% of all Chemistry questions in those years, about one question per paper, and the share has risen every year.
One class carries the chapter. Alkenes gave 16 of the 59 Main questions directly, and most of the 11 multi-step questions also turn on an alkene or alkyne step. Learn the alkene reactions properly and you can answer nearly half the chapter.
It is the base of all of Organic Chemistry. Markovnikov's rule, carbocation stability, rearrangements and ozonolysis come back in Alcohols, Haloalkanes and Carbonyl Compounds. Many of this chapter's multi-step questions end in another chapter's product: a diacid, a cyanohydrin, an isocyanide. A strong start here builds directly on Basics of Organic Chemistry.
Numericals are counting questions. All 14 Main numericals asked you to count something: atoms, π bonds, products, isomers or a percentage. There are no long calculations, just careful structures.
"Hydrocarbons is a chapter of reagents. Every reagent has one job and one rule. Learn them as a table, reagent by reagent, and the questions stop looking like puzzles and start looking like lookups." — AN Naik Sir, Chemistry HOD (IIT BHU, Ex-HOD Narayana Academy Hyderabad)
Real result · JEE 2026
Alkenes and multi-step conversions gave close to half of JEE Main's Hydrocarbons questions. Learn every reagent and its rule 1-on-1 with an IITian Chemistry HOD, and stop guessing products.
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Any plan for how to study Hydrocarbons for JEE should start from the papers. Here is how many questions JEE Main asked from this chapter in each of the last three years.
| Year | Questions | MCQ + Numerical | Share of Chemistry Qs |
|---|---|---|---|
| 2024 | 18 | 13 + 5 | 3.00% |
| 2025 | 20 | 16 + 4 | 4.21% |
| 2026 | 21 | 16 + 5 | 4.42% |
| Total | 59 | 45 + 14 | — |
And here are the same 59 questions sorted by what they test.
| Sub-topic | 2024 | 2025 | 2026 | Total |
|---|---|---|---|---|
| Alkenes (Markovnikov and anti-Markovnikov addition, hydroboration, ozonolysis, stability, halogen addition) | 5 | 6 | 5 | 16 |
| Multi-step conversions across classes | 5 | 4 | 2 | 11 |
| Alkanes (Kolbe electrolysis, free-radical halogenation, combustion, structure) | 1 | 3 | 4 | 8 |
| Alkynes (acidity, alkylation, Lindlar and Na/liquid NH3 reduction, hydration) | 3 | 1 | 4 | 8 |
| Aromatic hydrocarbons (Friedel–Crafts, directing effects, side-chain oxidation) | 2 | 0 | 3 | 5 |
| Isomer counting | 0 | 2 | 2 | 4 |
| Other chapter* | 2 | 4 | 0 | 6 |
| Not classified** | 0 | 0 | 1 | 1 |
| Total | 18 | 20 | 21 | 59 |
*Six questions filed under this chapter belong elsewhere: σ and π bond counting and carbon classification (General Organic Chemistry), name reactions of haloalkanes, and an Étard-type oxidation (Carbonyl Compounds). They are counted in the yearly totals only. **The reaction scheme of one 2026 question could not be recovered. Questions that use two classes are counted under the one that finishes them; multi-step questions that cross three or more classes are counted together.
The message of this table is simple. Alkenes gave 16 of 59 questions on their own. Add the multi-step conversions, which almost always pass through an alkene or alkyne, and you have 27 of 59, close to half. Aromatic hydrocarbons, which many students treat as the hardest part, gave only 5.
Pattern 1: Two reagents, one alkene, two products. 2024 asked for the products of propene with H+/H2O and with BH3 then H2O2/OH−. Another 2024 paper asked the same for 1-methylcyclohexene, and a third asked about cyclohexene with Cl2 in light and Cl2 in CCl4. Each question tests whether you know which reagent follows which rule.
Pattern 2: Ozonolysis forwards and backwards. 2025 asked which compound gives 3-methyl-6-oxoheptanal on ozonolysis, whether cis-2-butene gives ethanal, and matched C10H14 isomers with their ozonolysis products. 2026 asked to identify an alkene from its reductive ozonolysis products. Practise working backwards from the carbonyl products to the alkene.
Pattern 3: Alkyne chains. 2026 took a compound through Br2, excess NaNH2, CH3I and Na/liquid NH3. 2025 hydrated propyne to acetone and carried it on to a cyanohydrin and an amine. 2024 reduced 2-butyne with Na/liquid NH3 and then oxidised it with cold dilute KMnO4. The alkyne is the hinge of each sequence.
Pattern 4: Combustion and free-radical halogenation numericals. 2026 asked twice about an alkane that needs 8 mol of O2 for complete combustion, and asked for the dichloro products of 2-chlorobutane. 2024 asked how many alkanes form in the Kolbe electrolysis of a mixture of sodium acetate and sodium propanoate. These need a formula and careful counting.
Pattern 5: Statements on stability and directing effects. 2026 asked the stability order of four alkenes by hyperconjugation, true and false statements about Friedel–Crafts alkylation, and whether nitrobenzene undergoes Friedel–Crafts acylation. These are two-statement questions that need the reason as well as the fact.
This is the 12-year view that most guides skip. JEE Advanced asked this chapter in 9 of the 12 years from 2015 to 2026, missing 2017, 2018 and 2023.
| Year | Qs | What was asked |
|---|---|---|
| 2026 | 1 | Buta-1,3-diyne with two equivalents of NaNH2 and then excess trans-crotyl bromide; the maximum number of collinear carbons in the product (numerical) |
| 2025 | 1 | The most acidic hydrogen, where the conjugate base is a cyclopentadienyl-type aromatic anion (single correct) |
| 2024 | 1 | A sequence ending in a reaction with glycerol and a calcium soap; mass of the product (numerical) |
| 2022 | 5 | 15 mol of acetylene through a sequence with given yields; mass of the product (numerical) · isomeric tetraenes with no sp carbon (numerical) · CH2 groups in a product (numerical) · chiral products from complete ozonolysis (numerical) · statements on a reaction sequence (multi-correct) |
| 2021 | 3 | Na/liquid NH3 reducing an internal alkyne to a trans-alkene while a terminal alkyne survives (single correct) · two numericals on Mg2C3 → propyne → 2-butyne → hexamethylbenzene |
| 2020 | 1 | Transformations of an alkyne with Lindlar's catalyst (multi-correct) |
| 2019 | 4 | A reaction road map (multi-correct) · reactions that give an aromatic product, where benzene with Cl2 in UV light does not (multi-correct) · reactions that give propane (multi-correct) · OH groups in a product (numerical) |
| 2016 | 1 | Reactions that give tert-butylbenzene as the major product (multi-correct) |
| 2015 | 3 | 1,4-addition to a conjugated diene through an allylic carbocation (multi-correct) · two multi-correct reaction questions |
| Total | 20 | 9 numerical · 9 multi-correct · 2 single correct |
Five Advanced questions are shown only as images in the archive and could not be tagged with confidence; they are counted in the totals. One of them (2024) appears to be about lipids and may belong to Biomolecules.
Compared with JEE Main, the difference is length rather than new chemistry. Every reagent in the Advanced questions above also appears in Main: NaNH2, Lindlar's catalyst, Na in liquid NH3, ozone, Friedel–Crafts reagents and the red-hot iron tube. What changes is the number of steps and the need to keep exact track of moles, carbons and stereochemistry through all of them.
Advanced is built on long sequences. Five of the 20 questions were multi-step conversions, and two of the three alkyne questions were sequences too. Nine were numericals that ask for a mass, a count of groups or a count of isomers at the end of a chain. Isolated one-step questions are rare; you need to carry a structure accurately through four or five steps.
The smartest way to decide how to study Hydrocarbons for JEE is to match your time to each sub-topic. Use the time column in your mock tests: if you are consistently slower than the target, that sub-topic needs more practice, not more reading.
| Sub-topic | Main Qs (2024–26) | Advanced Qs (2015–26) | Difficulty | Target time |
|---|---|---|---|---|
| Alkenes | 16 | 2 | Medium | 60–90 s |
| Multi-step conversions | 11 | 5 | Medium–Hard | 2–3 min |
| Alkanes | 8 | 1 | Easy–Medium | 60–90 s |
| Alkynes | 8 | 3 | Medium | 90 s |
| Aromatic hydrocarbons | 5 | 3 | Medium | 90 s |
| Isomer counting | 4 | 1 | Medium–Hard | 2 min |
Difficulty and target time are our faculty's guidance for exam practice, not exam data.
Alkenes covers preparation by elimination, electrophilic addition of HX, H2O and X2, Markovnikov's rule and the peroxide effect, hydroboration–oxidation, ozonolysis, oxidation with KMnO4, and stability by hyperconjugation.
Multi-step conversions are sequences of three or more reagents, usually through an alkene or alkyne, that end in an alcohol, ketone, acid, amine or alkane.
Alkanes covers Wurtz and Kolbe reactions, decarboxylation, free-radical halogenation and its products, combustion, and physical properties such as melting point and branching.
Alkynes covers the acidity of terminal alkynes, alkylation of acetylides, partial reduction (Lindlar to cis, Na/liquid NH3 to trans), hydration with Hg2+, and preparation by double dehydrohalogenation.
Aromatic hydrocarbons covers aromaticity, electrophilic substitution, ortho/para and meta directing groups, Friedel–Crafts reactions and their limits, and side-chain oxidation.
Isomer counting asks for the number of structures that fit a formula and a condition, or the number of monochloro products.
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Markovnikov versus anti-Markovnikov, carbocation rearrangements and ozonolysis worked backwards are where students lose marks here. Work through them with your own faculty, at your pace, with every doubt answered the same day.
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Knowing how to study Hydrocarbons for JEE also means knowing what not to do. These are the mistakes we see most often when students solve this chapter's PYQs.
Keep this table open while you practise. Most of the chapter runs on these reactions, which is why learning how to study Hydrocarbons for JEE is mostly about knowing each reagent's job and rule.
| Sub-topic | Reaction / result |
|---|---|
| Alkane preparation | Wurtz: 2RX + 2Na → R–R · Kolbe: 2RCOONa electrolysed → R–R + 2CO2 (a mixture of two salts gives three alkanes) · decarboxylation: RCOONa + NaOH/CaO → RH |
| Alkane reactions | Free-radical halogenation: reactivity 3° H > 2° H > 1° H · combustion: CnH2n+2 needs (3n + 1)/2 mol O2 · branching lowers b.p.; symmetry raises m.p. (neopentane melts above n-pentane) |
| Alkene preparation | Alcohol + conc. H2SO4 (dehydration, may rearrange) · RX + alc. KOH (Saytzeff product) · vicinal dihalide + Zn · alkyne + Lindlar (cis) or Na/liq. NH3 (trans) |
| Alkene addition | HX: Markovnikov · HBr + peroxide: anti-Markovnikov · H+/H2O: Markovnikov alcohol · B2H6, H2O2/OH−: anti-Markovnikov alcohol, syn addition · Br2/CCl4: anti addition, vicinal dibromide · Cl2/hν at an allylic C–H: allylic substitution |
| Alkene oxidation | Cold dilute KMnO4 (Baeyer's reagent): syn diol · hot KMnO4/H+: cleavage to acids or ketones (=CH2 gives CO2) · O3, Zn/H2O: cleavage to aldehydes and ketones |
| Alkene stability | More alkyl groups on C=C = more hyperconjugation = more stable · trans more stable than cis · tetrasubstituted > trisubstituted > disubstituted > monosubstituted |
| Conjugated dienes | HBr or Br2: 1,2- and 1,4-addition through an allylic carbocation; 1,4 favoured at higher temperature |
| Alkyne preparation | Vicinal or geminal dihalide + 2 NaNH2 (or alc. KOH then NaNH2) · CaC2 + H2O → C2H2 · Mg2C3 + H2O → propyne |
| Alkyne reactions | Terminal C–H acidic: + Na or NaNH2 → acetylide (+ ½H2 with Na) · acetylide + 1° RX → longer alkyne · Hg2+/H2SO4: Markovnikov hydration to a ketone (ethyne gives ethanal) · red-hot Fe tube: cyclic trimer (ethyne → benzene, propyne → mesitylene, 2-butyne → hexamethylbenzene) |
| Aromaticity | Cyclic, planar, fully conjugated, 4n + 2 π electrons (Hückel) |
| Electrophilic substitution | Nitration (HNO3/H2SO4), halogenation (X2/FeX3), sulphonation, Friedel–Crafts alkylation (RX/AlCl3, rearranges, polyalkylates) and acylation (RCOCl/AlCl3, no rearrangement) |
| Directing effects | o/p directors: –OH, –NH2, –OR, –R, halogens (deactivating) · meta directors: –NO2, –CN, –CHO, –COOH, –SO3H · no Friedel–Crafts on nitrobenzene |
| Side-chain oxidation | Alkylbenzene with a benzylic H + KMnO4 → benzoic acid · tert-butylbenzene is not oxidised |
This is the core of how to study Hydrocarbons for JEE: one class at a time, in the order the syllabus builds them, then the multi-step questions that combine them. Do not move on until you can solve the PYQ types listed under each heading without notes.
Alkanes are quick marks, mostly numericals.
Physical properties are asked as statements. 2025 asked whether neopentane gives only one monosubstituted derivative (true: all twelve hydrogens are equivalent) and whether it melts higher than n-pentane (also true: its compact, symmetrical shape packs better in the solid, even though its boiling point is lower). 2025 also asked which alkane has exactly two secondary hydrogens, which is a matter of drawing each option and counting CH2 groups. 2026 asked which statements about preparing methane are correct, covering decarboxylation, Kolbe electrolysis, a Grignard reagent with water, and the Wurtz reaction. Kolbe electrolysis and the Wurtz reaction cannot give methane, because both join two carbon fragments.
Practice target: every alkane PYQ, plus a list of C4–C6 alkanes with their numbers of monochloro products.
This is the heart of the chapter. Build a reagent table with four columns: reagent, what adds, which carbon (Markovnikov or not), and whether a carbocation (and so a rearrangement) is involved.
Worked example from JEE Main 2025: which alkene gives 3-methyl-6-oxoheptanal on ozonolysis? The product has a CHO at C1 and a ketone at C6, so the two carbonyl carbons were joined by a C=C in a ring. Join them back: a six-membered ring with a methyl on the ketone carbon and another methyl two carbons from the aldehyde carbon. That is 1,4-dimethylcyclohex-1-ene.
Worked example from JEE Main 2026 (numerical): cyclohexene adds one mole of Br2. The product C6H10Br2 has M = 72 + 10 + 160 = 242, so the percentage of bromine is 160/242 × 100 ≈ 66%.
Practice target: 25 alkene problems, including ten ozonolysis questions solved backwards.
"For ozonolysis, never try to imagine the alkene. Write the carbonyl products side by side, join the two carbonyl carbons with a double bond, and remove the oxygens. If both carbonyls are in one molecule, the alkene was a ring." — AN Naik Sir, Chemistry HOD (IIT BHU, Ex-HOD Narayana Academy Hyderabad)
Alkynes are about four reactions, used in sequences:
Worked example from JEE Main 2026: a compound X goes through Br2, then excess NaNH2, then CH3I, then Na/liquid NH3, and the final product Y is asked. If X is styrene, Br2 gives the dibromide, excess NaNH2 gives the phenylacetylide, CH3I gives PhC≡CCH3, and Na/liquid NH3 gives trans-PhCH=CHCH3, with molar mass 118.
Practice target: 15 alkyne problems, including at least five that start from a dihalide.
A small group in recent papers, but its rules are needed in the multi-step questions too:
Worked example from JEE Main 2026: three statements about Friedel–Crafts alkylation. "Benzene with n-propyl chloride gives n-propylbenzene as the major product" is false, because the primary carbocation rearranges to the isopropyl cation and the main product is isopropylbenzene. "The product undergoes further alkylation" is true, because an alkyl group activates the ring. "An electron-donating group on the ring speeds up the reaction" is true for the same reason. Each statement tests one rule from the reaction table.
Practice target: 10 problems on directing effects and Friedel–Crafts.
These combine everything above. The method is the same every time: write the structure after each step, and do not skip a step in your head.
Worked example from JEE Main 2025: propyne with Hg2+/H2SO4 gives acetone; HCN gives the cyanohydrin (CH3)2C(OH)CN; H2/Ni reduces the nitrile to give 1-amino-2-methylpropan-2-ol.
Worked example from JEE Main 2025: 1,2-dibromocyclooctane with excess base gives cyclooctyne, Hg2+/H+ hydrates it to cyclooctanone, and Clemmensen reduction gives cyclooctane.
Worked example from JEE Main 2024: bromoethane with alcoholic KOH gives ethene, Br2 gives 1,2-dibromoethane, KCN gives NC–CH2CH2–CN, and hydrolysis gives succinic acid.
Isomer counting is the other half of this group. 2026 asked for the IUPAC name of an alkane with molar mass 72 and three primary carbons: M = 72 means C5H12, and three CH3 groups means one branch, so it is 2-methylbutane. 2026 also asked how many monochloro products come from all the C5H10 isomers that do not decolourise KMnO4; those isomers are the cycloalkanes, and counting carefully gives 14. 2025 asked about C9H12 isomers that give a negative Baeyer's test, which means aromatic isomers with no C=C in a side chain. In every case, the condition in the question cuts the list of isomers down first; count only after that.
Practice target: 20 multi-step PYQs. For each, write the structure after every arrow before looking at the options.
That is how to study Hydrocarbons for JEE class by class. Once you have finished, test yourself under exam conditions with our JEE test series, and bring any question that still does not make sense to the JEE Doubt Lab for a 1-on-1 explanation.
Ready for exam-level practice?
JEE Advanced asks Hydrocarbons as long sequences with numerical answers. Practise carrying a structure through every step 1-on-1 with an IITian Chemistry HOD.
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If you are deciding how to study Hydrocarbons for JEE Advanced as well as Main, this section is for you. Advanced goes further in four places.
Advanced 2022 took 15 mol of acetylene through a sequence with a yield at each step and asked for the mass of the product. Advanced 2021 started from Mg2C3: water gives propyne, NaNH2 and CH3I give 2-butyne, and a red-hot iron tube trimerises it to hexamethylbenzene; two numericals asked for masses further along. Multiply the yields in order and keep track of moles at every step.
Advanced 2021 asked what Na in liquid NH3 does to a molecule with both an internal and a terminal alkyne: the internal one becomes a trans-alkene, while the terminal one forms an acetylide and survives. Advanced asks you to decide which group reacts, not just what a reagent does.
Advanced numericals asked for collinear carbons (2026), isomeric tetraenes with no sp carbon (2022), chiral products of ozonolysis (2022), CH2 groups (2022) and OH groups (2019). In 2026, buta-1,3-diyne with two NaNH2 and trans-crotyl bromide gives a product where the four sp carbons and the two attached CH2 carbons lie on one line: 6 collinear carbons.
Advanced 2025 asked which hydrogen is most acidic; the answer is the CH2 of a cyclopentadiene-type ring, because its anion is aromatic. Advanced 2019 asked which reactions give an aromatic product, and benzene with Cl2 in UV light does not. Learn Hückel's rule well enough to apply it to ions.
"Advanced Hydrocarbons questions are long, but each step is a Main-level step. The students who get them right are the ones who draw every intermediate. Never carry a structure in your head across three arrows." — AN Naik Sir, Chemistry HOD (IIT BHU, Ex-HOD Narayana Academy Hyderabad)
The last step in how to study Hydrocarbons for JEE is an honest self-check. You should be able to answer "yes" to every line below without notes.
See how this chapter was asked: solve the real JEE Main 2026 April papers, free
All 9 JEE Main 2026 April shift papers as 3-hour online tests, with the official NTA answer key, an instant score and a step-by-step solution for every question.
Start the free test series →Hydrocarbons gave JEE Main 59 questions from 2024 to 2026, with its share rising every year, and JEE Advanced 20 questions from 2015 to 2026. Alkenes (16) and multi-step conversions (11) gave close to half the Main questions, alkanes and alkynes gave 8 each, and aromatic hydrocarbons only 5. Advanced is built on long sequences and counting numericals. So if you are working out how to study Hydrocarbons for JEE, the order is clear: build an alkene reagent table first, then alkynes and alkanes, then the aromatic rules, and practise multi-step sequences until you can carry a structure accurately through every arrow.
How we built this data. We went through every JEE Main shift paper from 2024, 2025 and 2026 and every JEE Advanced paper from 2015 to 2026, picked out each question from this chapter and tagged it by the class of compound it tests. Many reaction schemes in this chapter are archived only as images, so we identified those questions from text solutions of the same papers. Where a question still could not be identified with confidence, we counted it in the totals and said so instead of guessing.
If you want a faculty member to check your preparation, every pack starts with a free 30-minute mentorship call. See all Chemistry chapter packs on our JEE Chemistry coaching page, and once your exam is done, our JEE counselling team can help you turn your rank into the right college and branch.
JEE Main asked 18 questions from this chapter in 2024 (3.0% of Chemistry questions), 20 in 2025 (4.2%) and 21 in 2026 (4.4%), counting all shifts. That is about one question per paper, and the share has risen every year.
JEE Main questions are mostly medium: one or two reagents, each following a fixed rule. Multi-step sequences are harder because one wrong step spoils the answer. JEE Advanced questions are long sequences with numerical answers. If you follow this guide on how to study Hydrocarbons for JEE, the Main questions become routine with steady practice.
Yes. It gave 59 JEE Main questions from 2024 to 2026, with more each year, and it was asked in 9 of the 12 JEE Advanced exams from 2015 to 2026. Its rules also underpin the rest of Organic Chemistry.
No. Skipping it gives up about one question per JEE Main paper, and it makes Alcohols, Haloalkanes and Carbonyl Compounds much harder, because they reuse the same reagents and rules.
Master alkene reactions first, then multi-step conversions, then alkanes and alkynes. In JEE Main 2024–2026 alkenes and multi-step conversions gave 27 of the 59 questions, and adding alkanes and alkynes covers 43 of 59.
Long multi-step sequences with yields or masses, selective reactions in molecules with two reactive groups, counting numericals (collinear carbons, isomers, chiral products) and aromaticity of rings and ions. 9 of the 20 Advanced questions from 2015 to 2026 were numericals.
