Class 11 · Chemistry · English medium · Part 2
Class 11 Chemistry Part 2 companion
An interactive companion to Class 11 Chemistry Part 2: original explanations, reaction mechanisms, worked problems and practice for redox reactions, organic chemistry basics and hydrocarbons.
An original companion to Chemistry, NCERT Class 11 Chemistry (2026–27 edition). Official textbook ↗ ncert.nic.in
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Chapters
- ENHinglish
Chapter 7: Redox Reactions
Redox reactions are those in which oxidation and reduction happen together. - ENHinglish
Chapter 8: Organic Chemistry – Some Basic Principles and Techniques (Organic Chemistry Basics)
Basic principles of organic chemistry. - ENHinglish
Chapter 9: Hydrocarbons
Hydrocarbons (C and H only): classification; alkanes (CnH2n+2) — IUPAC naming, chain isomers, preparation (hydrogenation, Zn/H+, Wurtz, deca
Also in Hinglish
- Chapter 7: Redox Reactions (Hinglish)
- Chapter 8: Organic Chemistry – Kuch Basic Principles aur Techniques (Hinglish)
- Chapter 9: Hydrocarbons (Hinglish)
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alkaneऐल्केनA saturated open-chain hydrocarbon, CnH2n+2.Ch 9 · Hydrocarbonsalkeneऐल्कीनA hydrocarbon with a C=C double bond; CnH2n for one double bond.Ch 9 · Hydrocarbonsalkyneऐल्काइनA hydrocarbon with a C≡C triple bond; CnH2n-2 for one triple bond.Ch 9 · HydrocarbonsareneऐरीनA hydrocarbon containing an aromatic ring, usually a benzene ring.Ch 9 · HydrocarbonsaromaticityऐरोमैटिकताStability of a planar, fully delocalised ring with 4n + 2 π electrons.Ch 9 · HydrocarbonsC
carbanionकार्बऋणायनA species with a negatively charged carbon that carries a lone pair; usually sp³ hybridised and pyramidal.Ch 8 · Organic Chemistry – Some Basic Principles and Techniquescarbocationकार्बधनायनA species with a positively charged carbon that has only six valence electrons; it is sp² hybridised and planar.Ch 8 · Organic Chemistry – Some Basic Principles and Techniquescatenationश्रृंखलनThe ability of atoms of an element, above all carbon, to bond to one another in chains and rings.Ch 8 · Organic Chemistry – Some Basic Principles and TechniqueschromatographySeparation of a mixture by the different rates at which its components move over a stationary phase with a mobile phase.Ch 8 · Organic Chemistry – Some Basic Principles and TechniquesconformationसंरूपणAn arrangement of a molecule reached by rotation about a single bond, without breaking bonds.Ch 9 · HydrocarbonsD
directive influenceThe control a ring substituent has over where (o/p or m) and how fast the next substitution occurs.Ch 9 · Hydrocarbonsdisplacement reactionविस्थापन अभिक्रियाA reaction in which an element pushes another element out of its compound: X + YZ → XZ + Y.Ch 7 · Redox ReactionsdisproportionationअसमानुपातनA redox reaction in which one element, starting in a single oxidation state, is both oxidised and reduced.Ch 7 · Redox ReactionsE
electrochemical seriesCouples listed in order of standard electrode potential, ranking oxidising and reducing agents.Ch 7 · Redox Reactionselectromeric effectA temporary, complete shift of a π electron pair to one atom of a multiple bond while a reagent attacks.Ch 8 · Organic Chemistry – Some Basic Principles and Techniqueselectrophileइलेक्ट्रॉनरागीA reagent that accepts an electron pair from an electron-rich centre.Ch 8 · Organic Chemistry – Some Basic Principles and Techniqueselectrophileइलेक्ट्रॉनस्नेहीAn electron-seeking species, such as H+ or NO2+.Ch 9 · Hydrocarbonselectrophilic substitutionइलेक्ट्रॉनस्नेही प्रतिस्थापनReplacement of a ring hydrogen by an electrophile through a σ-complex, keeping the ring aromatic.Ch 9 · HydrocarbonsF
free radicalमुक्त मूलकAn atom or group with an unpaired electron, formed by homolytic cleavage of a bond.Ch 8 · Organic Chemistry – Some Basic Principles and Techniquesfree radicalमुक्त मूलकAn atom or group with an unpaired electron, formed by homolysis of a bond.Ch 9 · Hydrocarbonsfunctional groupप्रकार्यात्मक समूहAn atom or group of atoms that gives a compound its characteristic reactions, such as –OH or –COOH.Ch 8 · Organic Chemistry – Some Basic Principles and TechniquesG
geometrical isomerismज्यामितीय समावयवताIsomerism from different arrangements of groups about a C=C bond, caused by restricted rotation.Ch 9 · HydrocarbonsH
half reactionअर्ध अभिक्रियाThe oxidation part or the reduction part of a redox reaction written on its own, with the electrons shown.Ch 7 · Redox Reactionshomologous seriesसमजातीय श्रेणीA family of compounds with the same functional group whose successive members differ by a CH2 unit.Ch 8 · Organic Chemistry – Some Basic Principles and Techniqueshyperconjugationअतिसंयुग्मनDelocalisation of the σ electrons of a C–H bond into a neighbouring π system or empty p orbital.Ch 8 · Organic Chemistry – Some Basic Principles and TechniquesI
inductive effectप्रेरणिक प्रभावPermanent polarisation passed along σ bonds from a polar bond; it fades within about three bonds.Ch 8 · Organic Chemistry – Some Basic Principles and TechniquesisomerismसमावयवताThe existence of different compounds with the same molecular formula; such compounds are isomers.Ch 8 · Organic Chemistry – Some Basic Principles and TechniquesM
Markovnikov ruleIn adding H–X to an unsymmetrical alkene, H goes to the doubly bonded carbon with more hydrogens.Ch 9 · HydrocarbonsN
nucleophileनाभिकरागीA reagent that donates an electron pair to an electron-poor centre.Ch 8 · Organic Chemistry – Some Basic Principles and TechniquesO
oxidationऑक्सीकरणLoss of electrons by a species, seen as a rise in oxidation number (classically, gain of oxygen or loss of hydrogen).Ch 7 · Redox Reactionsoxidation numberऑक्सीकरण संख्याThe charge an atom would carry if every shared electron pair belonged wholly to the more electronegative atom.Ch 7 · Redox Reactionsoxidising agentऑक्सीकारकA species that accepts electrons and so oxidises another; it is itself reduced.Ch 7 · Redox Reactionsozonolysisओज़ोनी अपघटनCleavage of a C=C bond by ozone and then Zn/H₂O, giving two carbonyl compounds.Ch 9 · HydrocarbonsP
peroxide effectपरॉक्साइड प्रभावAnti-Markovnikov addition of HBr to an unsymmetrical alkene in the presence of a peroxide, by a radical chain.Ch 9 · HydrocarbonsR
redox coupleThe oxidised and reduced forms of one species in a half reaction, written oxidised/reduced, such as Zn²+ / Zn.Ch 7 · Redox Reactionsredox reactionअपचयोपचय अभिक्रियाA reaction in which one species is oxidised while another is reduced, so oxidation numbers change.Ch 7 · Redox Reactionsredox titrationA titration between an oxidant and a reductant whose end point is seen as a colour change.Ch 7 · Redox Reactionsreducing agentअपचायकA species that donates electrons and so reduces another; it is itself oxidised.Ch 7 · Redox ReactionsreductionअपचयनGain of electrons by a species, seen as a fall in oxidation number (classically, loss of oxygen or gain of hydrogen).Ch 7 · Redox ReactionsresonanceअनुनादDescription of a molecule as a hybrid of Lewis structures that differ only in the positions of electrons.Ch 8 · Organic Chemistry – Some Basic Principles and Techniquesretardation factorRf: the distance moved by a substance divided by the distance moved by the solvent front, both from the base line.Ch 8 · Organic Chemistry – Some Basic Principles and TechniquesS
salt bridgeलवण सेतुA tube of electrolyte gel joining two half-cells; ions move through it, keeping both solutions neutral without mixing them.Ch 7 · Redox Reactionsstandard electrode potentialमानक इलेक्ट्रोड विभवThe reduction potential of a half-cell at unit concentrations, 1 bar and 298 K, measured against the hydrogen electrode (0.00 V).Ch 7 · Redox ReactionsStock notationWriting a metal's oxidation number as a Roman numeral in brackets, as in iron(III) chloride.Ch 7 · Redox ReactionsT
torsional strainThe repulsion between bonds on adjacent atoms that raises the energy of eclipsed conformations.Ch 9 · Hydrocarbonsncert.ai is an independent learning companion aligned to the NCERT curriculum. It is not affiliated with or endorsed by NCERT.