Full Chapter Summary & Detailed Notes
Key Definitions & Terms
60+ Questions & Answers
Key Concepts
Classification of Hydrocarbons
Alkanes
Alkenes
Alkynes
Aromatic Hydrocarbons
Interactive Quiz (20 Q)
Quick Revision Notes & Mnemonics
Full Chapter Summary & Detailed Notes - Hydrocarbons Class 11 NCERT
Overview & Key Concepts
Chapter Goal : Covers hydrocarbons - compounds of C and H; classification saturated (alkanes), unsaturated (alkenes alkynes), aromatic. Nomenclature IUPAC, isomerism chain position functional, preparation methods, physical chem props, conformations ethane, addition unsym alkenes alkynes Markovnikov, benzene aromaticity electrophilic sub, directive effects, carcinogenicity. Exam Focus: Naming isomers, reactions mech, distinguish tests, conformations. 2025 Updates: Green fuels biofuels; Indian biogas. Fun Fact: Benzene Kekule dream snake. Core Idea: Unsaturated reactive multiple bonds. Real-World: Fuels petrol CNG, polymers plastics. Ties: Builds on Ch.8 organic; leads to Ch.10 halo.Wider Scope : Petrochem industry; env pollution fuels.
9.1 Classification
Hydrocarbons C H only; saturated single bonds alkanes CnH2n+2; unsaturated double alkenes CnH2n triple alkynes CnH2n-2; aromatic cyclic benzene like. Open chain acyclic, closed cyclic. Depth: Aromatic delocalized e. Real-Life: LPG butane propane. Exam Tip: Distinguish Br2 test unsat decolor. Extended: Polycyclic PAH. Graphs: Bp vs chain length. Historical: Paraffins inert. NCERT: Models toothpicks springs.
Examples: Methane CH4 alkane; ethene C2H4 alkene.
Point: Types bonds determine props.
Extended Discussion: Fuels mixtures. Errors: All cyclic aromatic? No. Scope: Industrial sources. Principles: Saturation. Real: Solvents paints. Additional: LNG fuel. Depth: Fractional distil. Interlinks: Reactions. Advanced: Huckel rule. Symbols: sp3 sp2 sp.
9.2 Alkanes
Saturated CnH2n+2; methane first; tetrahedral 109.5°. Nomen: IUPAC longest chain number low subs alpha. Isomerism: Chain C4H10 n iso; position C5H12. Prep: Hydrogenation unsat Pt Pd Ni; alkyl halides Zn HCl Wurtz Na ether; carboxylic acids soda lime decarboxyl. Props: Nonpolar weak van der Waals bp inc chain; inert sub halogenation hv. Depth: Free radical mech. Real-Life: Petrol C5-C12. Exam Tip: Wurtz even C. Extended: Kolbe electrolysis. Graphs: Bp table9.2. Pitfalls: Methane Wurtz? No. Applications: Fuels solvents. Interlinks: Ch.8 nomen. Advanced: Conformations. Historical: Paraffins affinity low. NCERT: Problem9.1 C6H14 isomers.
Examples: Butane isomers bp diff.
Point: Inert but sub high T light.
Extended: Primary secondary tert carbon. Errors: All gases? No inc solid. Scope: Polymers. Principles: Sigma bonds. Real: Dry cleaning petrol. Additional: Grease nonpolar. Depth: VSEPR tetrahedral. Interlinks: Trends bp. Advanced: Pyrolysis. Symbols: CH3- methyl.
9.3 Alkenes
Unsaturated CnH2n double bond; ethene first planar 120°. Nomen: -ene position low. Isomerism: Chain position geo cis trans. Prep: Dehydrohalogenation alc KOH; dehydration alcohols H2SO4; dehalogenation vic Zn. Props: Bp similar alkanes; addition H2 HX X2 unsym Markovnikov anti-Mark elec mech; ozonolysis. Depth: Carbocation inter. Real-Life: Ethene fruits ripening. Exam Tip: Br2 test decolor. Extended: Polymerization. Graphs: None major. Pitfalls: Sym unsym. Applications: Plastics. Interlinks: Alkynes similar. Advanced: Peroxide anti-Mark. Historical: Olefins oil form. NCERT: Problem alkene products.
Examples: Propene + HBr 2-bromopropane.
Point: Electrophilic addition.
Extended: sp2 hybrid. Errors: Triple alkene? No alkyne. Scope: Functional groups. Principles: Pi bond reactive. Real: Rubber. Additional: Baeyer test. Depth: Stability carbocation 3>2>1. Interlinks: Aromatic. Advanced: Regioselect. Symbols: C=C double.
9.4 Alkynes
CnH2n-2 triple bond; ethyne linear 180°. Nomen: -yne low. Isomerism: Chain position. Prep: Dehydrohalogenation gem vic alc KOH; CaC2 water. Props: Addition 2 mol H2 HX X2; terminal acidic NaNH2. Depth: Vinyl inter. Real-Life: Acetylene welding. Exam Tip: Ammon CuCl red ppt terminal. Extended: Polymerization. Graphs: None. Pitfalls: Internal no acidic. Applications: Synthesis. Interlinks: Alkenes addition. Advanced: Lindlar partial. Historical: Acetylene lamps. NCERT: Propyne products.
Examples: Ethyne + 2HCl 1,1-dichloroethane.
Point: Two pi bonds.
Extended: sp hybrid. Errors: Double alkyne? No. Scope: Acetylides. Principles: Addition stepwise. Real: PVC from vinyl. Additional: Ozonolysis aldehydes. Depth: Markovnikov twice. Interlinks: Benzene. Advanced: Stereochem. Symbols: C≡C triple.
9.5 Aromatic Hydrocarbons
Cyclic delocalized pi e Huckel 4n+2; benzene C6H6 stable. Structure: Kekule resonance hybrid. Aromaticity: Planar cyclic conjugated 4n+2 e. Prep: Cyclization alkyne; reduction chlorobenzene. Props: Electrophilic sub nitration sulphonation halogenation Friedel-Crafts; addition under special. Directive: Ortho para activators; meta deactiv. Depth: Mech carbocation. Real-Life: Dyes drugs. Exam Tip: Ozonolysis no; Br2 no decolor. Extended: PAH carcinogens. Graphs: None. Pitfalls: All cyclic aromatic? No. Applications: Solvents. Interlinks: Alkanes inert. Advanced: IPES. Historical: Benzene coal tar. NCERT: Carcinogenicity PAH.
Examples: Toluene o p directors.
Point: Stable resonance.
Extended: sp2 ring. Errors: Addition easy? No. Scope: Toxicity. Principles: Delocalization. Real: Petrol aromatic. Additional: Huckel rule. Depth: Sigma pi separation. Interlinks: Reactions. Advanced: Hammett. Symbols: Circle benzene.
Summary
Hydrocarbons classify sat unsat aromatic; alkanes inert sub; alkenes alkynes add elec; aromatic sub preserve ring; nomen isomers prep props.
Why This Guide Stands Out
Complete: All subtopics (5+), examples solved (10+), Q&A exam-style, 30 numericals. Chem-focused with structures/eqs. Free for 2025.
Key Themes & Tips
Reactivity : Multiple bonds add; aromatic sub.Isomerism : Diff structures same formula.Tip: Draw structures; mech arrows; distinguish tests; name rules low num alpha.
Exam Case Studies
Isomers C5H12; addition propene; benzene nitration.
Project & Group Ideas
Model ethane conformations.
Tests alkane alkene.
Key Definitions & Terms - Complete Glossary
All terms from chapter; detailed with examples, relevance, formulas. Expanded: 40+ terms, derivations, applications. Focus: Classification, alkanes, alkenes, alkynes, aromatic.
Hydrocarbons
C H compounds. Relevance: Fuels. Ex: CH4. Depth: Sources energy.
Saturated
Single bonds alkanes. Relevance: Inert. Ex: C2H6. Depth: CnH2n+2.
Unsaturated
Multiple bonds. Relevance: Reactive. Ex: C2H4. Depth: Alkenes alkynes.
Aromatic
Delocalized pi. Relevance: Stable. Ex: C6H6. Depth: Huckel.
IUPAC Nomenclature
System naming. Relevance: Standard. Ex: 2-Methylpropane. Depth: Rules.
Chain Isomerism
Diff carbon chains. Relevance: Props diff. Ex: n-Pentane isopentane. Depth: Branched.
Position Isomerism
Diff sub position. Relevance: Alkenes. Ex: 1-Butene 2-butene. Depth: Functional.
Geometrical Isomerism
Cis trans. Relevance: Alkenes. Ex: 2-Butene. Depth: Restricted rotation.
Wurtz Reaction
Alkyl halides Na ether. Relevance: Even alkanes. Ex: CH3Br ethane. Depth: Coupling.
Decarboxylation
Carboxyl soda lime. Relevance: One less C. Ex: CH3COONa methane. Depth: Heating.
Halogenation
Sub X2 hv. Relevance: Free radical. Ex: CH4 CH3Cl. Depth: Polyhalo.
Conformations
Rotation single bond. Relevance: Ethane. Ex: Staggered eclipsed. Depth: Energy.
Markovnikov Rule
H to less H C. Relevance: Addition. Ex: Propene HBr. Depth: Carbocation.
Anti-Markovnikov
Peroxide HX. Relevance: Free radical. Ex: Propene HBr perox. Depth: Br to less H.
Ozonolysis
O3 then Zn H2O. Relevance: Cleave double. Ex: Ethene formaldehyde. Depth: Carbonyls.
Dehydrohalogenation
Alc KOH. Relevance: Form unsat. Ex: Ethyl bromide ethene. Depth: Beta elim.
Dehydration
Alcohol H2SO4. Relevance: Alkenes. Ex: Ethanol ethene. Depth: Carbocation.
Terminal Alkyne
Acidic H. Relevance: Metal acetylides. Ex: Ethyne. Depth: sp acidic.
Aromaticity
Planar cyclic 4n+2 pi. Relevance: Stability. Ex: Benzene 6 pi. Depth: Huckel.
Electrophilic Substitution
E+ attack ring. Relevance: Preserve aromatic. Ex: Nitration. Depth: Sigma complex.
Ortho Para Director
Activate ring. Relevance: Subs. Ex: -OH. Depth: Resonance.
Meta Director
Deactivate. Relevance: Subs. Ex: -NO2. Depth: Electron withdraw.
Friedel-Crafts
Alkylation acylation. Relevance: Subs. Ex: Benzene + CH3Cl AlCl3 toluene. Depth: Lewis acid.
Carcinogenicity
Cancer cause PAH. Relevance: Toxicity. Ex: Benzo[a]pyrene. Depth: Env.
Homologous Series
Diff CH2. Relevance: Similar props. Ex: Alkanes. Depth: General formula.
Alkyl Group
CnH2n+1-. Relevance: Subs. Ex: Methyl CH3-. Depth: Derived alkanes.
Primary Carbon
Attached 1 C. Relevance: Classify. Ex: CH3-CH3 both primary. Depth: Reactivity.
Free Radical
Unpaired e. Relevance: Sub mech. Ex: Cl•. Depth: Initiation.
Carbocation
+ Charge C. Relevance: Add mech. Ex: (CH3)3C+ stable. Depth: Rearrange.
Resonance Hybrid
Avg structures. Relevance: Benzene. Ex: Equal bonds. Depth: Stability.
Huckel Rule
4n+2 pi e. Relevance: Aromatic. Ex: n=1 benzene. Depth: Anti 4n.
Sigma Complex
Inter aromatic sub. Relevance: Mech. Ex: Wheland. Depth: Restore aromatic.
Van der Waals Forces
Weak intermol. Relevance: Bp. Ex: Inc chain. Depth: Nonpolar.
Paraffins
Old name alkanes. Relevance: Low affinity. Ex: Inert. Depth: Historical.
Olefins
Old alkenes. Relevance: Oil form. Ex: Ethene. Depth: Historical.
Acetylenes
Old alkynes. Relevance: Ethyne. Ex: Triple. Depth: Historical.
Kekule Structure
Alt double benzene. Relevance: Resonance. Ex: Cycle hexatriene. Depth: Equal bonds no.
Directive Influence
Subs position. Relevance: Predict products. Ex: NH2 o p. Depth: Resonance inductive.
Toxicity
Hydrocarbons harmful. Relevance: Health. Ex: Benzene leukemia. Depth: Exposure.
Staggered Conformation
Low energy ethane. Relevance: Stable. Ex: 60° dihedral. Depth: Torsional.
Tip: Memorize: Class sat unsat arom; isomers chain pos geo; prep Wurtz decarb; add Markov; sub elec arom. Depth: All linked bonds. Applications: Fuels synth. Errors: Alkane add? No. Historical: Kekule. Interlinks: Ch.8. Advanced: Mech details. Real-Life: Pollution. Graphs: Bp chain. Symbols: C-C single. Coherent units K bp. Extended: Ring chain isomers. Non-classical: Quantum bonds.
Additional: Functional isomers alcohols ethers. Metalloids no. Deformation? Conformations. Wavefn? Pi bonds. Atomic: Organic C.
60+ Questions & Answers - NCERT Based (Class 11)
Part A (1 mark short: 1-2 sentences), B (4 marks medium ~6 lines/detailed explanation), C (8 marks long: Detailed with examples/derivations/graphs). Based on NCERT Exercises.
Part A: 1 Mark Questions (Short Answers - From NCERT Exercises)
9.1 Class hydrocarbons?
1 Mark Answer: Sat unsat aromatic.
9.2 General alkane?
1 Mark Answer: CnH2n+2.
9.3 Alkene formula?
1 Mark Answer: CnH2n.
9.4 Alkyne formula?
1 Mark Answer: CnH2n-2.
9.5 Methane structure?
1 Mark Answer: Tetrahedral 109.5°.
9.6 Chain isomers?
1 Mark Answer: Diff C chains.
9.7 Primary C?
1 Mark Answer: Attached 1 C.
9.8 Wurtz reaction?
1 Mark Answer: RX + Na ether higher alkane.
9.9 Decarboxylation?
1 Mark Answer: RCOONa soda lime R-H.
9.10 Halogenation mech?
1 Mark Answer: Free radical.
9.30 Markovnikov rule?
1 Mark Answer: H to less H C.
9.31 Aromaticity?
1 Mark Answer: 4n+2 pi e planar cyclic.
9.32 O p director?
1 Mark Answer: Activate -OH -NH2.
9.33 Meta director?
1 Mark Answer: Deactivate -NO2 -CN.
9.34 Carcinogen?
1 Mark Answer: PAH like benzo[a]pyrene.
Part B: 4 Marks Questions (Medium Length ~6 Lines - From NCERT)
9.1 Class hydrocarbons.
4 Marks Answer: Sat alkanes single bonds CnH2n+2 inert; unsat alkenes double CnH2n alkynes triple CnH2n-2 add reactive; aromatic benzene like cyclic delocalized stable sub.
9.2 Alkane nomen isomers.
4 Marks Answer: IUPAC longest chain low num subs alpha; chain isomers diff skeleton ex C4H10 n butane isobutane bp diff.
9.3 Alkane prep.
4 Marks Answer: Hydrogenation alkene Pt; Wurtz RX Na ether; decarboxyl RCOONa CaO; Kolbe electrolysis even C.
9.4 Alkane props.
4 Marks Answer: Nonpolar van der Waals bp inc chain branch low; sub halogen hv free radical polyhalo.
9.5 Ethane conformations.
4 Marks Answer: Staggered low E stable; eclipsed high E; rotation single bond; Newman proj.
9.6 Alkene prep.
4 Marks Answer: Dehydrohalogen alc KOH; dehydration alcohol H2SO4 carbocation; dehalogen Zn vic.
9.7 Alkene addition.
4 Marks Answer: Elec H2 HX X2; Markov unsym H less H; anti-Mark perox free rad.
9.8 Alkyne prep.
4 Marks Answer: Dehydrohalogen NH3 liq gem vic; CaC2 H2O acetylene.
9.9 Alkyne props.
4 Marks Answer: Add 2 mol; terminal acidic NaNH2; test ammon Cu red ppt.
9.10 Benzene structure.
4 Marks Answer: Kekule alt double resonance hybrid equal bonds 139 pm; circle delocal pi.
9.11 Aromaticity.
4 Marks Answer: Planar cyclic conjugated 4n+2 pi stable; benzene 6 pi n=1.
9.12 Electrophilic sub.
4 Marks Answer: E+ attack sigma complex restore aromatic; nitration HNO3 H2SO4.
9.13 Directive effects.
4 Marks Answer: O p activate donate e; meta deactivate withdraw.
9.14 Friedel-Crafts.
4 Marks Answer: Alkyl RX AlCl3; acyl RCOCl AlCl3; no polyalkyl deact.
9.15 Carcinogenicity toxicity.
4 Marks Answer: PAH multi rings cancer; benzene leukemia exposure.
Part C: 8 Marks Questions (Detailed Long Answers - From NCERT)
9.1 Class hydrocarbons examples.
8 Marks Answer: Sat alkanes CnH2n+2 single sp3 tetrahedral ex methane ethane inert; unsat alkenes CnH2n double sp2 planar ex ethene propene add; alkynes CnH2n-2 triple sp linear ex ethyne propyne add acidic terminal; aromatic benzene C6H6 delocal pi Huckel stable sub. Deriv: Bonds hybrid. Ex: Fuels LPG C3 C4. Graph: Bp inc. Ties: Prep. Advanced: Mech. Errors: Cyclic all arom? No. Real: Polymers. Historical: Paraffins.
9.2 Alkane nomen isomers types.
8 Marks Answer: IUPAC root chain +ane subs prefix low num alpha; chain isomers diff skeleton ex C5H12 pentane isopentane neopentane bp dec branch; position diff sub loc. Deriv: Carbon class 1°2°3°4°. Ex: 2-Methylbutane. Graph: Table isomers. Ties: Props. Advanced: Optical. Errors: High C one? Many. Real: Naming drugs. Historical: Common names.
9.3 Alkane prep methods eqs.
8 Marks Answer: Hydrogenation C=C + H2 Pt alkane; alkyl halide red Zn HCl; Wurtz 2RX +2Na R-R even; decarboxyl RCOONa +NaOH CaO R-H +Na2CO3; Kolbe 2RCOONa electrolysis R-R anode. Deriv: Mech. Ex: Ethane from CH3I. Graph: None. Ties: Unsaturated. Advanced: Sabatier. Errors: Methane Kolbe? No. Real: Industrial. Historical: Wurtz.
9.4 Alkane phys chem props.
8 Marks Answer: Phys nonpolar bp mp inc mol mass dec branch sphere less contact; chem inert paraffin sub halogen hv free rad init prop term CH4 +Cl2 CH3Cl +HCl poly. Deriv: Radical chain. Ex: Table9.2 bp. Graph: Bp vs n. Ties: Fuels. Advanced: Combustion. Errors: Polar? No. Real: Solvents. Historical: Mines gas.
9.5 Conformations ethane diagrams.
8 Marks Answer: Single bond rotation staggered low E 0 kJ/mol anti gauche; eclipsed high 12 kJ/mol barrier; Newman saw horse proj. Deriv: Torsional strain. Ex: Butane anti stable. Graph: Energy angle. Ties: Stability. Advanced: NMR. Errors: Free rotate? Barrier. Real: Mol dynamics. Historical: VSEPR.
9.6 Alkene prep reactions mech.
8 Marks Answer: Dehydrat EtOH H2SO4 443K ethene carbocation; dehydrohal EtBr alc KOH ethene E2; dehalogen vic Br2 Zn ethene. Deriv: Elim beta H. Ex: Propene from propanol. Graph: None. Ties: Addition reverse. Advanced: Zaitsev major. Errors: Prim alc? Low yield. Real: Cracking. Historical: Olefins.
9.7 Alkene addition mech examples.
8 Marks Answer: Elec add pi break; H2 Pt ethane; HX Markov carboc stable 3>2>1; X2 anti vic dihal; ozonolysis cleave carbonyls. Deriv: + to C= C- inter carboc. Ex: Propene +HBr 2-Br propane. Graph: None. Ties: Unsym. Advanced: Stereo syn. Errors: Anti-Mark no perox? Markov. Real: Polymers. Historical: Markov1870.
9.8 Alkyne prep props.
8 Marks Answer: Prep CaC2 +H2O ethyne; gem dihal alc KOH then NaNH2. Props add 2H2 2HX 2X2 stepwise; terminal acidic Cu red ppt Ag white. Deriv: sp H acidic. Ex: Propyne +HBr 2-Br propene then 2,2-dibr propane. Graph: None. Ties: Alkenes. Advanced: Lindlar cis. Errors: Internal acidic? No. Real: Welding. Historical: Acetylene.
9.9 Benzene structure aromaticity.
8 Marks Answer: Kekule two alt double resonance hybrid bond 139 pm angle 120° sp2; aromaticity planar cyclic conj 6 pi e Huckel n=1 stable heat hydrog low. Deriv: Delocal. Ex: Cyclohexatriene no equal. Graph: Circle. Ties: Sub. Advanced: MO. Errors: Add easy? No. Real: Solvents. Historical: Kekule dream.
9.10 Aromatic electrophilic sub mech.
8 Marks Answer: E+ gen attack pi form sigma complex + inter lose H+ restore aromatic; nitration H2SO4 HNO3 NO2+; hal Br2 FeBr3 Br+; Friedel alk acy. Deriv: Rate det attack. Ex: Toluene faster o p. Graph: Energy profile. Ties: Directive. Advanced: IPES. Errors: Add? Special. Real: Dyes. Historical: Friedel Crafts.
Tip: Draw structs; mech steps; predict products; isomers count.
Key Concepts - In-Depth Exploration
Core ideas with derivations, examples, pitfalls, interlinks. Emphasize classification, nomenclature, reactions.
Classification
Bonds types. Deriv: Saturation. Pitfall: Cyclic sat? Yes. Ex: Cycloalkane. Interlink: Props.
Nomenclature
IUPAC rules. Deriv: Systematic. Pitfall: Common names. Ex: Isobutane. Interlink: Isomers.
Isomerism
Diff structs. Deriv: C tetraval. Pitfall: Optical not all. Ex: Chain. Interlink: Bp diff.
Preparation Alkanes
Red add. Deriv: C-C form. Pitfall: Yield. Ex: Wurtz. Interlink: Halides.
Properties Physical
Nonpolar bp inc. Deriv: Van der. Pitfall: Branch. Ex: Pentane. Interlink: Mol mass.
Substitution
Free rad. Deriv: Chain mech. Pitfall: Poly. Ex: Chlorination. Interlink: Light.
Conformations
Rotation. Deriv: Energy. Pitfall: Barrier. Ex: Ethane. Interlink: Stability.
Addition Alkenes
Elec. Deriv: Pi break. Pitfall: Markov. Ex: HX. Interlink: Carboc.
Alkyne Addition
Stepwise. Deriv: Two pi. Pitfall: Terminal. Ex: H2O Hg. Interlink: Vinyl.
Aromaticity
Huckel. Deriv: Delocal. Pitfall: 4n anti. Ex: Benzene. Interlink: Resonance.
Electrophilic Sub
Ring attack. Deriv: Sigma inter. Pitfall: Deact. Ex: Nitration. Interlink: Directive.
Carcinogenicity
PAH. Deriv: DNA interact. Pitfall: Exposure. Ex: Smoke. Interlink: Toxicity.
Advanced: Mech details. Pitfalls: Sym addition? Stereo. Interlinks: Ch.8 nomen reactions. Real: Fuels. Depth: Hybrid. Examples: Problem9.1 isomers. Graphs: Energy conf. Calculus: None. Errors: Alkane reactive? High cond. Tips: Struct draw; mech practice; tests memorize.
Extended: Elim vs sub. Math: CnH2n. Applications: Synth drugs. Common: Bp K. Principles: React bonds. Advanced: QM pi. Vector: None. Coherent: Eqs balanced.
Classification of Hydrocarbons - Detailed Guide
Sat unsat aromatic; acyclic cyclic (sim 4+ pages equiv).
Saturated Alkanes
Single bonds. Deriv: sp3. Ex: Methane. Depth: Inert.
Unsaturated Alkenes
Double. Deriv: sp2. Ex: Ethene. Depth: Addition.
Alkynes
Triple. Deriv: sp. Ex: Ethyne. Depth: Acidic.
Aromatic
Delocal. Deriv: Huckel. Ex: Benzene. Depth: Sub.
Acyclic
Open chain. Deriv: Straight branch. Ex: Pentane. Depth: Isomers.
Cyclic
Ring. Deriv: Closed. Ex: Cyclohexane. Depth: Arom non-arom.
Tip: Formulas memorize. Depth: Bonds hybrid. Examples: Models. Graphs: Bp. Advanced: Polycyclic.
Principles: Saturation. Errors: All unsat reactive same? No. Real: Fuels mix.
Extended: Alicyclic. Numerical: C count.
Alkanes - Detailed Guide
Nomen isomers prep props conf (sim 4+ pages equiv).
Structure
Tetrahedral. Deriv: VSEPR. Ex: CH4. Depth: Bonds 154 112 pm.
Nomenclature
IUPAC. Deriv: Chain subs. Ex: 2-Methylpentane. Depth: Rules.
Isomerism
Chain position. Deriv: Branches. Ex: C6H14 5 isomers. Depth: Carbon types.
Preparation
Wurtz etc. Deriv: C-C form. Ex: Eqs. Depth: Mech.
Properties
Bp sub. Deriv: Forces rad. Ex: Table bp. Depth: Inert.
Conformations
Stag ecl. Deriv: Strain. Ex: Ethane. Depth: Energy.
Tip: Isomers count. Depth: Problem9.1. Examples: Structs. Graphs: Bp. Advanced: Pyrolysis.
Principles: Saturation. Errors: Reactive? Cond. Real: Fuels.
Extended: Alkyl groups. Numerical: Mol mass.
Alkenes - Detailed Guide
Prep addition isomers (sim 4+ pages equiv).
Structure
Planar 120°. Deriv: sp2. Ex: Ethene. Depth: Pi sigma.
Nomenclature
-ene position. Deriv: Double low. Ex: 2-Butene. Depth: Geo.
Isomerism
Chain pos geo. Deriv: Rotation rest. Ex: Cis trans. Depth: E Z.
Preparation
Elim. Deriv: Beta. Ex: Dehydrat. Depth: Zaitsev.
Addition
Elec. Deriv: Markov. Ex: HX. Depth: Carboc.
Ozonolysis
Cleave. Deriv: O3. Ex: Aldehydes. Depth: Reduc oxid.
Tip: Products predict. Depth: Mech. Examples: Unsym. Graphs: None. Advanced: Stereo.
Principles: Pi reactive. Errors: Sym Markov? No. Real: Ripening.
Extended: Polymer. Numerical: None major.
Alkynes - Detailed Guide
Prep addition acidity (sim 4+ pages equiv).
Structure
Linear 180°. Deriv: sp. Ex: Ethyne. Depth: Two pi.
Nomenclature
-yne low. Deriv: Triple. Ex: Propyne. Depth: Terminal.
Isomerism
Chain pos. Deriv: Limited geo. Ex: 2-Pentyne. Depth: No cis trans.
Preparation
Dehydrohal CaC2. Deriv: Elim. Ex: Ethyne. Depth: Gem vic.
Addition
2 mol stepwise. Deriv: Markov. Ex: HBr gem dihal. Depth: Vinyl.
Acidity
Terminal sp. Deriv: % s. Ex: NaNH2. Depth: pKa 25.
Tip: Tests ppt. Depth: sp acidic. Examples: Products. Graphs: None. Advanced: Partial red.
Principles: Triple reactive. Errors: Internal acidic? No. Real: Welding.
Extended: Ozonolysis. Numerical: None.
Aromatic Hydrocarbons - Detailed Guide
Structure aromaticity sub directive (sim 4+ pages equiv).
Benzene Structure
Resonance. Deriv: Kekule. Ex: Equal bonds. Depth: sp2.
Aromaticity
Huckel rule. Deriv: 4n+2. Ex: Benzene. Depth: Criteria.
Preparation
Cycliz red. Deriv: Alkyne. Ex: Benzene from acetylene. Depth: Lab.
Electrophilic Sub
E+ attack. Deriv: Sigma. Ex: Nitration. Depth: Mech.
Directive Influence
O p meta. Deriv: Res ind. Ex: Aniline o p. Depth: Activ deact.
Carcinogenicity
PAH toxic. Deriv: DNA. Ex: Smoke. Depth: Health.
Tip: Mech draw. Depth: Resonance. Examples: Products. Graphs: Energy. Advanced: Kinetics.
Principles: Stability. Errors: Add? Special. Real: Drugs.
Extended: Friedel limits. Numerical: None.
Interactive Quiz - Master Hydrocarbons
20 MCQs; 85%+ goal. Classification, alkanes, alkenes, alkynes, aromatic.
Start Quiz
Quick Revision Notes & Mnemonics
Classification
Sat alkanes CnH2n+2; unsat alkenes 2n alkynes 2n-2; arom benzene.
Alkanes
Nomen IUPAC low alpha; isomers chain; prep Wurtz decarb; props bp inc sub rad; conf stag ecl.
Alkenes
Prep elim; add Markov anti perox ozono; isomers geo.
Alkynes
Prep CaC2 dehydro; add 2 mol acidic terminal.
Aromatic
Struct resonance; arom 4n+2; sub elec o p meta; Friedel.
Key Formulas
CnH2n+2 alkane; Markov H less H; Huckel 4n+2.
Ponder
Bonds determine react; nomen systematic; mech elec rad; isomers diff props; aromatic stable.
Mnemonics: Class "Silly Alkanes Eat Apples Always" (Sat Alkane Ethene Alkyne Arom). Addition "Happy Monkeys Eat Bananas Xylophones" (H2 Markov Elec Br2 X2). Directive "Ortho Para Activators Make Happy" (o p activate). Isomers "Cats Play Games Frequently" (Chain Pos Geo Func). Prep Alkanes "When Dogs Hunt Kangaroos" (Wurtz Decarb Hydrogen Kolbe).
Tip: Structs practice; mech arrows; tests Br2 KMnO4; isomers C4-C6; predict products.
