CBSE Class 11 (Science) Hydrocarbons — practice questions
120 free MCQs with worked solutions. Tap any question for the answer + explanation, or practice them all in the app.
Practice CBSE Class 11 (Science) Hydrocarbons in the app →As per your syllabus, the general formula of an alkane (saturated open-chain hydrocarbon) is which?As per your syllabus, + Fig 9.1, the H-C-H bond angle in methane and the carbon hybridisation are which?As per your syllabus, (ii), the Wurtz reaction uses which reagent + solvent for coupling alkyl halides?As per your syllabus, (i), heating CH₃COONa with NaOH + CaO (soda-lime) produces which gas?As per your syllabus, (ii), in Kolbe electrolytic synthesis of alkanes, the alkane gas is liberated at which eAs per your syllabus, the rate of HALOGENATION of alkanes (F₂, Cl₂, Br₂, I₂) decreases in which order?As per your syllabus, the rate of substitution of HYDROGENS in alkane halogenation goes in which order (by carAs per your syllabus, Mechanism, the FIRST step of methane chlorination under sunlight is best described as whAs per your syllabus, the STAGGERED form of ethane is more stable than ECLIPSED for which reason?As per your syllabus, hydrogenation of an alkene to an alkane uses dihydrogen with which kind of catalyst?As per your syllabus, in ethene the C-C bond consists of which σ/π combination, and the carbons are which hybrAs per your syllabus, geometrical (cis-trans) isomerism in alkenes arises because of which feature of the doubAs per your syllabus, the dipole moment of cis-but-2-ene (0.33 D) and trans-but-2-ene (≈ 0 D) shows which formAs per your syllabus, partial reduction of an alkyne to a CIS alkene uses which catalyst?As per your syllabus, reduction of an internal alkyne with Na in LIQUID NH₃ gives which kind of alkene?As per your syllabus, HBr addition to propene gives mainly which product?As per your syllabus, the peroxide (Kharasch) effect on HBr addition to propene gives mainly which product?As per your syllabus, the peroxide effect is observed only with which hydrogen halide?As per your syllabus, the rate-determining intermediate in HBr + propene addition is which species?As per your syllabus, mild oxidation of an alkene with cold dilute KMnO₄ (Baeyer's reagent) gives which producAs per your syllabus, reductive ozonolysis of an alkene with O₃ followed by Zn/H₂O gives which class of producAs per your syllabus, addition of conc. H₂SO₄ to an alkene followed by water gives mainly which class of compoAs per your syllabus, the carbon-carbon triple bond in ethyne (HC≡CH) consists of which σ/π combination?As per your syllabus, the C-H bond in ethyne is unusually ACIDIC because of which factor?As per your syllabus, calcium carbide (CaC₂) reacts with water to give which gas?As per your syllabus, terminal alkynes react with sodium metal to liberate which gas + sodium acetylide?As per your syllabus, addition of water to ethyne in dilute H₂SO₄ with HgSO₄ catalyst gives which final producAs per your syllabus, addition of water to propyne under HgSO₄/H₂SO₄ gives mainly which product (Markovnikov)?As per your syllabus, three molecules of ethyne polymerise over a hot red-hot tube to give which compound?As per your syllabus, HBr addition to propyne gives which Markovnikov product?As per your syllabus, reduction of an alkyne to a TRANS alkene uses which reagent system?As per your syllabus, the general molecular formula of an open-chain alkyne is which?As per your syllabus, the THREE criteria for aromaticity (Hückel) are which set?As per your syllabus, for benzene the value of n in Hückel's (4n+2) π electron formula is which?As per your syllabus, all six C-C bond lengths in benzene are equal to approximately which value?As per your syllabus, the carbon atoms of benzene are which hybridisation?As per your syllabus, nitration, the actual ELECTROPHILE that attacks benzene in HNO₃ + H₂SO₄ mixture is whichAs per your syllabus, halogenation, the role of anhydrous AlCl₃ (or FeCl₃) in benzene chlorination is which?As per your syllabus, Friedel-Crafts ALKYLATION of benzene uses which reagent system?As per your syllabus, Friedel-Crafts ACYLATION of benzene uses an acyl halide + AlCl₃ to generate which electrAs per your syllabus, which of the following groups is a META-directing substituent on benzene?As per your syllabus, halogens (-Cl, -Br) on benzene are which kind of directors despite their deactivating -IThe general formula for alkanes is:LPG, a common domestic fuel, stands for:Coal gas is obtained from coal by:Saturated hydrocarbons whose carbon atoms form a ring are called:Methane occurs naturally in:General formula of the alkane homologous series is:Each H-C-H bond angle in methane is:In alkanes, the C-C bond length is about:How many chain isomers does C5H12 have?How many structural isomers are possible for hexane, C6H14?About how many isomers are possible for C10H22?Isomers that differ only in their carbon skeleton are:A carbon atom bonded to four other carbon atoms is:The end carbon atoms of an open alkane chain are always:2,2-Dimethylpropane is commonly called:Groups formed by removing one hydrogen from an alkane are:Which alkyl halides are not reduced to alkanes by Zn and dilute HCl?Wurtz coupling of one alkyl halide gives alkanes with:Soda lime is a mixture of:Heating sodium propanoate with soda lime gives:Kolbe electrolysis of aqueous sodium acetate produces:Petrol removes grease stains because grease is:Boiling points of alkanes rise with molecular mass because:More branching lowers an alkane's boiling point because molecules become:Chlorination of methane in diffused sunlight is a:Order of reactivity of halogens with alkanes is:Free radical halogenation has initiation, propagation and:Chlorination of methane begins with homolysis of Cl2 because:Ethane forms as a by-product in chlorination of methane because:n-Alkanes heated with anhydrous AlCl3 and HCl gas undergo:n-Hexane over Cr2O3 on alumina at 773 K forms benzene. This is:Which n-alkane gives toluene on aromatisation?Breaking higher alkanes into smaller molecules by heat is:Arrangements interconverted by rotation about a C-C single bond are:Energy difference between staggered and eclipsed ethane is about:In which projection is the rear carbon drawn as a circle?Alkenes are called olefins, a name meaning:The pi bond of C=C is weaker than its sigma bond because of:Bond enthalpy of the C≡C bond in ethyne is about:Loosely held pi electrons make alkenes react mainly with:Methene is short lived. The first stable alkene is:But-1-ene and but-2-ene are an example of:Cis-trans isomerism in alkenes arises because:In a cis alkene, the two identical groups lie:trans-But-2-ene has nearly zero dipole moment because:Compared with the cis isomer, a solid trans alkene usually has:Partial hydrogenation of an alkyne over Lindlar's catalyst gives:Reducing an alkyne with sodium in liquid ammonia gives:For dehydrohalogenation with alcoholic KOH, the halogen order is:Dihalides with halogens on adjacent carbon atoms are called:Vicinal dihalides heated with zinc metal give:Alcohols heated with concentrated H2SO4 form alkenes by:Ethene is a colourless gas with:Reactivity of hydrogen halides towards alkenes follows:By Markovnikov's rule, the negative part of the adding molecule goes to the carbon with:Propene with HBr and no peroxide gives mainly:Anti-Markovnikov addition of HBr with peroxide is called the:The peroxide effect does not occur with HCl because:Propene with water and a little concentrated H2SO4 gives mainly:In ozonolysis, the ozonide is cleaved using:Ozonolysis of but-2-ene gives:Polythene is made by polymerising:Milk crates and plastic buckets are commonly moulded from:Which hydrocarbon is burnt with oxygen in welding torches?How many pi bonds are present in one ethyne molecule?Industrially, ethyne is made by treating calcium carbide with:Ethyne is more acidic than ethene because its carbon orbitals have:Which compound does not react with sodamide to give a salt?Ethyne reacts with sodium metal to give sodium acetylide and:Propyne with dilute H2SO4 and HgSO4 gives mainly:Which polymer made from ethyne can conduct electricity?Aromatic compounds that lack a benzene ring are called:How many position isomers does dibromobenzene have?In a disubstituted benzene, the 1,2 relationship is called:Benzene was first isolated in 1825 by:Kekule's fixed structure predicted how many 1,2-dibromobenzenes?A planar cyclic conjugated ring is aromatic if its pi electron count is:Every C-C bond length in benzene is about: