MCQ Questions For Class 11 Chemistry Chapter 13 Hydrocarbons

Please refer to MCQ Questions Hydrocarbons for Chapter 13 Class 11 Chemistry given below. All MCQ questions are provided with answers. These MCQ Questions for Class 11 Chemistry are designed based on the chapters given in your CBSE NCERT Textbook for Class 11 Chemistry. These MCQ Questions are expected to come in your class 11 Board exams.

Question. Hydrocarbon (A) reacts with bromine by substitution to form an alkyl bromide which by Wurtz reaction is converted to gaseous hydrocarbon containing less than four carbon atoms. (A) is
(a) CH CH
(b) CH₂ CH₂
(c) CH₃ — CH₃
(d) CH₄ 

Question. With respect to the conformers of ethane, which of the following statements is true?
(a) Bond angle changes but bond length remains ame.
(b) Both bond angle and bond length change.
(c) Both bond angle and bond length remain same.
(d) Bond angle remains same but bond length changes.

Question. The correct statement regarding the comparison of staggered and eclipsed conformations of ethane, is
(a) the eclipsed conformation of ethane is morestable than staggered conformation even though the eclipsed conformation has torsional strain
(b) the staggered conformation of ethane is more stable than eclipsed conformation, because staggered conformation has no torsional strain
(c) the staggered conformation of ethane is less stable than eclipsed conformation, because staggered conformation has torsional strain
(d) the eclipsed conformation of ethane is more stable than staggered conformation, because eclipsed conformation has no torsional strain.

Question. Which of the following alkane cannot be made in good yield by Wurtz reaction?
(a) n-Hexane
(b) 2, 3-Dimethylbutane
(c) n-Heptane
(d) n-Butane

Question. The alkane that gives only one monochloro product on chlorination with Cl₂ in presence of diffused sunlight is
(a) 2,2-dimethylbutane
(b) neopentane
(c) n-pentane
(d) isopentane.

Question. Liquid hydrocarbons can be converted to a mixtureof gaseous hydrocarbons by
(a) oxidation
(b) cracking
(c) distillation under reduced pressure
(d) hydrolysis.

Question. The most stable conformation of n-butane is
(a) gauche
(b) staggered
(c) skew boat
(d) eclipsed. 

Question. Which of the following is used as an antiknocking material?
(a) Glyoxal
(b) Freon
(c) T.E.L.
(d) Ethyl alcohol 

Question. Reactivity of hydrogen atoms attachedto different carbon atoms in alkanes has the order
(a) tertiary > primary > secondary
(b) primary > secondary > tertiary
(c) both (a) and (b)
(d) tertiary > secondary > primary.

Question. Dihedral angle in staggered form of ethane is
(a) 0°
(b) 120°
(c) 60°
(d) 180°

Question. In the commercial gasolines, the type ofhydrocarbons which are more desirable is
(a) linear unsaturated hydrocarbon
(b) toluene
(c) branched hydrocarbon
(d) straight-chain hydrocarbon. 

Question. The compound that will react most readily with gaseous bromine has the formula
(a) C₃H₆
(b) C₂H₂
(c) C₄H₁₀
(d) C₂H₄

Question. Reaction of HBr with propene in the presence of peroxide gives
(a) isopropyl bromide
(b) 3-bromopropane
(c) allyl bromide
(d) n-propyl bromide.

Question. Which reagent converts propene to 1-propanol?
(a) H₂O, H₂SO₄
(b) B₂H₆, H₂O₂, OH–
(c) Hg(OAc)₂, NaBH₄/H₂O
(d) Aq. KOH 

Question. Which is maximum stable?
(a) 1-Butene
(b) cis-2-Butene
(c) trans-2-Butene
(d) All have same stability. 

Question. Wet ether is not used as a solvent in Wurtz reaction, because the water present in it 
(a) hydrolysis RX to ROH
(b) reduces RX to RH
(c) destroy the Na metal
(d) reacts with R—R       

Question. The synthesis of 3-octyne is achieved by adding a bromoalkane into a mixture of sodium amide and an alkyne. 
The bromoalkane and alkyne respectively are
(a) BrCH₂CH₂CH₂CH₂CH₃ and CH₃CH₂C=CH
(b) BrCH₂CH₂CH₃ and CH3CH₂CH₂C=CH
(c) BrCH₂CH₂CH₂CH₂CH₃ and CH₃C=CH
(d) BrCH₂CH₂CHH_2H3 and CH₃CH₂C = CH     

Question. The chemicals and the reaction conditions required for the preparation of ethane are 
(a) C₂H₅ I, Zn -Cu, C₂H₅OH
(b) CH₃Cl, Na, H₂O
(c) KOOC-CH = CH-COOK electrolysis
(d) CH₃CO₂Na, NaOH, CaO, Δ     

Question. Methyl bromide is converted into ethane by heating it in ether medium with 
(a) Al
(b) Zn
(c) Na
(d) Cu       

Question. By which one of the following compounds both CH₄ and CH₃—CH₃ can be prepared in one step? 
(a) CH₃I
(b) CH₃OH
(c) CH₃CH₂I
(d) C₂H₅OH       

Question. For synthesis of 1-butene, CH₃ Mgl should be treated with
(a) propene
(b) 2-chloropropene
(c) allyI chloride
(d) ethyl chloride     

Question. Butene-I may be converted to butane by reaction with
(a) Zn-HCl
(b) Sn-HCl 
(c) Zn-Hg
(d) Pd/H₂     

Question. Pure methane can be produced by
(a) Wurtz reaction
(b) Kolbe’s electrolytic method
(c) soda lime decarboxylation
(d) reduction with H₂     

Question. Alkyl halides react with dialkyl copper reagents to give
(a) alkenyl halides
(b) alkanes 
(c) alkyl copper halides
(d) alkenes     

Question. Product fo1med on electro! ysis of potassium salt of fumaric and maleic acid is 
(a) ethane
(b) ethene
(c) ethyne
(d) methane       

Question. 2-Butene shows geometrical isomerism due to
(a) restricted rotation about double bond
(b) free rotation about double bond
(c) free rotation about single bond
(d) chiral carbon. 

Question. 2-Bromopentane is heated with potassium ethoxide in ethanol. The major product obtained is
(a) trans-2-pentene
(b) 1-pentene
(c) 2-ethoxy pentane
(d) 2-cis-pentene.

Question. Geometrical isomers differ in
(a) position of functional group
(b) position of atoms
(c) spatial arrangement of atoms
(d) length of carbon chain. 

Question. In preparation of alkene from alcohol using Al₂O₃ which is the effective factor?
(a) Porosity of Al₂O₃
(b) Temperature
(c) Concentration
(d) Surface area of Al₂O₃ 

Question. The reaction, CH₂= CH – CH₃ + HBr → CH₃CHBr – CH₃ is
(a) electrophilic substitution
(b) free radical addition
(c) nucleophilic addition
(d) electrophilic addition. 

Question. Reduction of 2-butyne with sodium in liquidammonia gives predominantly
(a) cis-2-butene
(b) no reaction
(c) trans-2-butene
(d) n-butane. 

Question. The restricted rotation about carbon carbon double bond in 2-butene is due to
(a) overlap of one s and sp²-hybridized orbitals
(b) overlap of two sp²-hybridized orbitals
(c) overlap of one p and one sp2-hybridized orbitals
(d) sideways overlap of two p-orbitals.

Question. Which one of the following can exhibit cis-trans isomerism?
(a) CH₃ – CHCl – COOH
(b) H – C≡ C – Cl
(c) ClCH =CHCl
(d) ClCH₂ – CH₂Cl

Question. The pair of electrons in the given carbanion,CH₃C C –, is present in which of the followingorbitals?
(a) sp²
(b) sp
(c) 2p
(d) sp³

Question. Which of the following organic compounds hassame hybridization as its combustion product (CO₂)?
(a) Ethane
(b) Ethyne
(c) Ethene
(d) Ethanol

Question. Which of the following has zero dipole moment?
(a) 1-Butene
(b) 2-Methyl-1-propene
(c) cis-2-Butene
(d) trans-2-Butene 

Question. One of the following which does not observe the anti-Markownikoff’s addition of HBr, is
(a) pent-2-ene
(b) propene
(c) but-2-ene
(d) but-1-ene. 

Question. Which of the following reagents will be able to distinguish between 1-butyne and 2-butyne?
(a) NaNH₂
(b) HCl
(c) O₂
(d) Br₂

Question. The cylindrical shape of an alkyne is due to
(a) two sigma C – C and one p C – C bonds
(b) one sigma C – C and two p C – C bonds
(c) three sigma C – C bonds
(d) three p C – C bonds.

Question. A compound is treated with NaNH₂ to give sodium salt. Identify the compound.
(a) C₂H₂
(b) C₆H₆
(c) C₂H₆
(d) C₂H₄ 

Question. The shortest C–C bond distance is found in
(a) diamond
(b) ethane
(c) benzene
(d) acetylene. 

Question. Acetylenic hydrogens are acidic because
(a) sigma electron density of C – H bond in acetylene is nearer to carbon, which has 50%s-character 
(b) acetylene has only open hydrogen in eachcarbon 
(c) acetylene contains least number of hydrogens among the possible hydrocarbons having twocarbons 
(d) acetylene belongs to the class of alkynes with molecular formula, CnH₂n^–2.

Question. Considering the state of hybridization of carbon atoms, find out the molecule among the following which is linear?
(a) CH₃ — CH= CH — CH₃
(b) CH₃ — C≡ C — CH₃
(c) CH₂ CH — CH₂ — C≡ CH
(d) CH₃ — CH2 — CH₂ — CH₃

Question. When acetylene is passed through dil. H₂SO₄ in thepresence of HgSO₄, the compound formed is
(a) acetic acid
(b) ketone
(c) ether
(d) acetaldehyde.

Question. Which is the most suitable reagent among the following to distinguish compound (3) from rest of the compounds?
(1) CH₃ – C C – CH₃
(2) CH₃ – CH₂ – CH2 – CH₃
(3) CH₃ – CH2C≡ CH
(4) CH₃ – CH= CH₂
(a) Bromine in carbon tetrachloride
(b) Bromine in acetic acid
(c) Alk. KMnO₄
(d) Ammoniacal silver nitrate

Question. The oxidation of benzene by V₂O₅ in the presence of air produces
(a) maleic anhydride
(b) benzoic acid
(c) benzaldehyde
(d) benzoic anhydride.

Question. Some meta-directing substituents in aromaticsubstitution are given. Which one is most deactivating?
(a) — COOH
(b) — NO₂
(c) — C≡ N
(d) — SO₃H

Question. Which of the following compounds will not undergo Friedel-Crafts reaction easily?
(a) Nitrobenzene
(b) Toluene
(c) Cumene
(d) Xylene

Question. Among the following compounds the one that is most reactive towards electrophilic nitration is
(a) benzoic acid
(b) nitrobenzene
(c) toluene
(d) benzene.

Question. Benzene reacts with CH₃Cl in the presence of anhydrous AlCl₃ to form
(a) chlorobenzene
(b) benzyl chloride
(c) xylene
(d) toluene. 

Question. Which of the following can be used as the halide component for Friedel–Crafts reaction?
(a) Chlorobenzene
(b) Bromobenzene
(c) Chloroethene
(d) Isopropyl chloride

Question. Consider the nitration of benzene using mixed conc. H₂SO₄ and HNO₃. If a large amount of KHSO₄is added to the mixture, the rate of nitration will be
(a) unchanged
(b) doubled
(c) faster
(d) slower.

Question. Nitrobenzene can be prepared from benzene byusing a mixture of conc. HNO₃ and conc. H₂SO₄. In the mixture, nitric acid acts as a/an
(a) acid
(b) base
(c) catalyst
(d) reducing agent.

Question. The correct order of reactivity towards theelectrophilic substitution of the compounds aniline (I), benzene (II) and nitrobenzene (III) is
(a) III > II > I
(b) II > III > I
(c) I < II > III
(d) I > II > III

Question. Electrophile in the case of chlorination of benzene in the presence of FeCl₃ is
(a) Cl
(b) FeCl₃
(c) Cl⁺
(d) Cl^–

Question. The reactive species in the nitration of benzene is
(a) NO₃
(b) HNO₃
(c) NO₂ ⁺
(d) NO₂^–

Question. In Friedel-Crafts reaction, toluene can be prepared by
(a) C₆H₆ + CH₃Cl
(b) C₆H₅Cl + CH₄
(c) C₆H₆ + CH₂Cl₂
(d) C₆H₆ + CH₃COCl 

Question. In Friedel-Crafts alkylation, besides AlCl₃ the other reactants are
(a) C₆H₆ + CH₃Cl
(b) C₆H₆ + CH₄
(c) C₆H₆ + NH₃
(d) C₆H₆ + CH₃COCl

Question. Which one of these is not compatible with arenes?
(a) Electrophilic additions
(b) Delocalisation of p-electrons
(c) Greater stability
(d) Resonance

Question. The order of decreasing reactivity towards an electrophilic reagent, for the following would be
(i) benzene (ii) toluene
(iii) chlorobenzene (iv) phenol
(a) (ii) > (iv) > (i) > (iii)
(b) (iv) > (iii) > (ii) > (i)
(c) (iv) > (ii) > (i) > (iii)
(d) (i) > (ii) > (iii) > (iv)