Chapter 25

Benzyl chloride \(\left(\mathrm{C}_{6} \mathrm{H}_{5} \mathrm{CH}_{2} \mathrm{Cl}\right)\) can be prepared from toluene by chlorination with (1) \(\mathrm{SO}_{2} \mathrm{Cl}_{2}\) (2) \(\mathrm{SOCl}_{2}\) (3) \(\mathrm{Cl}_{2}\) (4) \(\mathrm{NaOCl}\) (a) 1 and 2 (b) 1 and 4 (c) 2 and 3 (d) 4

To \(0.037 \mathrm{~g}\) of an alcohol, \(\mathrm{R}-\mathrm{OH}\) was added to \(\mathrm{CH}_{3} \mathrm{Mgl}\) and the gas evolved measured \(11.2 \mathrm{~cm}^{3}\) at STP. What is the molecular mass of \(\mathrm{R}-\mathrm{OH} ?\) (a) 46 (b) 60 (c) 74 (d) 88

In which of the following compounds, the weight percentage of \(\mathrm{C}\) and \(\mathrm{H}\) are 80 and 20 respectively? (a) \(\mathrm{C}_{2} \mathrm{H}_{6}\) (b) \(\mathrm{CH}_{4}\) (c) \(\mathrm{C}_{6} \mathrm{H}_{6}\) (d) \(\mathrm{C}_{2} \mathrm{H}_{3}\)

\(\mathrm{CHCOONa} \stackrel{\text { Electolysis }}{\longrightarrow}[\mathrm{A}] \frac{\mathrm{L}_{2}}{\text { liquid } \mathrm{NH}_{\mathrm{I}}}[\mathrm{B}]\) Here, [B] is (a) \(\mathrm{CH} \equiv \mathrm{CH}\) (b) \(\mathrm{NaC} \equiv \mathrm{CNa}\) (c) \(\mathrm{I}-\mathrm{C} \equiv \mathrm{C}-\mathrm{I}\) (d) \(\mathrm{IC} \equiv \mathrm{CNa}\)

In the reaction of phenol with \(\mathrm{CHCl}_{3}\) and aqueous \(\mathrm{NaOH}\) at \(70^{\circ} \mathrm{C}(343 \mathrm{~K})\), the electrophile attacking the ring is (a) \(\mathrm{CHCl}_{3}\) (b) \(\mathrm{CHCl}_{2}\) (c) \(\mathrm{CCl}_{2}\) (d) \(\mathrm{COCl}_{2}^{*}\)

\(\mathrm{C}-\mathrm{C}-\mathrm{C} \equiv \mathrm{C} \stackrel{\angle \mathrm{A}}{\mathrm{B}}>\mathrm{C}-\mathrm{C} \equiv \mathrm{C}-\mathrm{C}\) Here, \([\mathrm{A}]\) and \([\mathrm{B}]\) are (a) alc. \(\mathrm{KOH}\) and \(\mathrm{NaNH}_{2}\) (b) \(\mathrm{NaNH}_{2}\) and Lindlar catalyst (c) \(\mathrm{NaNH}_{2}\) and alcoholic \(\mathrm{KOH}\) (d) Lindlar catalyst and \(\mathrm{NaNH}_{2}\)

Benzene reacts with \(\mathrm{CH}_{3} \mathrm{COCl}\) in the presence of anhydrous \(\mathrm{AlCl}_{3}\) to give (a) \(\mathrm{C}_{6} \mathrm{H}_{5} \mathrm{CH}_{3}\) (b) \(\mathrm{C}_{6} \mathrm{H}_{5} \mathrm{Cl}\) (c) \(\mathrm{C}_{6} \mathrm{H}_{5} \mathrm{O}_{2} \mathrm{Cl}\) (d) \(\mathrm{C}_{6} \mathrm{H}_{5} \mathrm{COCH}_{3}\)

Which is most easily dehydrohalogenated? CC(C)(C)C ClC1C=CC=CC1Cl ClC1C=CCC=C1 ClC1=CCC=CC1 II (a) I (b) II (c) III (d) cannot be determined

Which of the following compounds does not dissolve in concentrated \(\mathrm{H}_{2} \mathrm{SO}_{4}\) even on warming? (a) aniline (b) benzene (c) ethylene (d) hexane

When propyne is treated with aqueous \(\mathrm{H}_{2} \mathrm{SO}_{4}\) in presence of \(\mathrm{HgSO}_{4}\) the major product is (a) acetone (b) propanol (c) propanal (d) propyl hydrogen sulphate

Which is the decreasing order of strength of bases \(\mathrm{OH}^{-}, \mathrm{NH}_{2}^{-}, \mathrm{HC} \equiv \mathrm{C}^{-}\)and \(\mathrm{CH}_{3} \mathrm{CH}_{2}^{-} ?\) (a) \(\mathrm{CH}_{3} \mathrm{CH}_{2}^{->} \mathrm{NH}_{2}^{->} \mathrm{HC}=\mathrm{C}^{-}>\mathrm{OH}^{-}\) (b) \(\mathrm{HC} \equiv \mathrm{C}^{-}>\mathrm{CH}_{3} \mathrm{CH}_{2}^{-}>\mathrm{NH}_{2}^{-}>\mathrm{OH}^{-}\) (c) \(\mathrm{OH}^{-}>\mathrm{NH}_{2}^{-}>\mathrm{HC}=\mathrm{C}^{-}>\mathrm{CH}_{3} \mathrm{CH}_{2}^{-}\) (d) \(\mathrm{NH}_{2}^{-}>\mathrm{HC}=\mathrm{C}^{-}>\mathrm{OH}^{-}>\mathrm{CH}_{3} \mathrm{CH}_{2}^{-}\)

\(\mathrm{Ph}-\mathrm{C} \equiv \mathrm{C}-\mathrm{CH}_{3} \stackrel{\mathrm{Hg}_{1}^{-3} \mathrm{H}^{\prime}}{\longrightarrow} \mathrm{A}\). Here, \(\mathrm{A}\) is (a) CCC(=O)c1ccccc1 (b) CC(=O)Cc1ccccc1 (c) CCC(O)c1ccccc1 (d) CC(O)Cc1ccccc1

Identify the products of the following reaction, \(\mathrm{CH}_{3} \mathrm{C} \equiv \mathrm{CCH}_{2} \mathrm{CH}_{3} \stackrel{\text { (i) } \mathrm{O}_{3}}\) (ii) hydrolysis \(?+?\) (a) \(\mathrm{CH}_{3} \mathrm{COOH}+\mathrm{CO}_{2}\) (b) \(\mathrm{CH}_{3} \mathrm{COOH}+\mathrm{HOOC} \cdot \mathrm{CH}_{2} \mathrm{CH}_{3}\) (c) \(\mathrm{CH}_{3} \mathrm{CHO}+\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CHO}\) (d) \(\mathrm{CH}_{3} \mathrm{COOH}+\mathrm{CH}_{3} \mathrm{COCH}_{3}\)

Identify the reagent from the following list which can easily distinguish between 1 -butyne and 2 -butyne? (a) bromine, \(\mathrm{CCl}_{4}\) (b) \(\mathrm{H}_{2}\), Lindlar catalyst (c) dilute \(\mathrm{H}_{2} \mathrm{SO}_{4}, \mathrm{HgSO}_{4}\) (d) ammonical coprocess chloride

Identify the reagent from the following list which can easily distinguish between 1 -butyne and 2 -butyne? (a) bromine, \(\mathrm{CCl}_{4}\) (b) \(\mathrm{H}_{2}\), Lindlar catalyst (c) dilute \(\mathrm{H}_{2} \mathrm{SO}_{4}, \mathrm{HgSO}_{4}\) (d) ammonical coprocess chloride

The reaction of propene with HOCl proceeds via the addition of (a) \(\mathrm{H}^{+}\)in the first step (b) \(\mathrm{Cl}^{+}\)in the first step (c) \(\mathrm{OH}\) - in the first step (d) \(\mathrm{Cl}^{+}\)and \(\mathrm{OH}^{-}\)in a single step

The reaction of HBr with in the presence of peroxide will give C=C(C)C (a) CC(C)(C)C (b) \(\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{Br}\) (c) CC(C)C \(\mathrm{Br}\) (d) CCC(C)C

Propyne and propene can be distinguished by (a) conc. \(\mathrm{H}_{2} \mathrm{SO}_{4}\) (b) \(\mathrm{Br}_{2}\) in \(\mathrm{CCl}_{4}\) (c) diluted \(\mathrm{H}_{2} \mathrm{SO}_{4}\) (d) \(\mathrm{AgNO}_{3}\) in ammonia

The product(s) obtained via oxymercuration \(\left(\mathrm{HgSO}_{4}\right.\) \(+\mathrm{H}_{2} \mathrm{SO}_{4}\) ) of but-1-yne would give (a) CC(C)=O (b) \(\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CH}_{2}-\mathrm{CHO}\) (c) \(\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CHO}+\mathrm{HCHO}\) (d) \(\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{COOH}+\mathrm{HCOOH}\)

The reaction of CC=Cc1ccc(O)cc1 with HBr gives (a) CC(Br)Cc1ccc(O)cc1 (b) CCC(Br)c1ccc(O)cc1 CC(Br)Cc1ccc(Br)cc1 (c) (d) CCC(Br)c1ccc(Br)cc1

Ethene and ethyne can be distinguished by (a) \(\mathrm{Br}_{2}\) water (b) \(\mathrm{KMnO}_{4}\) solution (c) cuprous chloride solution (d) any of the above

2,3 -dimethyl hexane contains .... tertiary .... secondary and ..... primary carbon atoms, respectively. (a) \(2,4,3\) (b) \(3,2,4\) (c) \(4,3,2\) (d) \(2,2,4\)

2,3 -dimethyl hexane contains .... tertiary .... secondary and ..... primary carbon atoms, respectively. (a) \(2,4,3\) (b) \(3,2,4\) (c) \(4,3,2\) (d) \(2,2,4\)

Which among the following will give a precipitate with ammonical silver nitrate? (a) 2 -butene (b) 2 -butyne (c) chlorobenzene (d) 3 -methyl-1-butyne

Which of the following sequence of reagents can be used for the conversion of \(\mathrm{C}_{6} \mathrm{H}_{5} \mathrm{CH}_{2} \mathrm{CH}_{3}\) into \(\mathrm{C}_{6} \mathrm{H}_{5} \mathrm{CH}=\mathrm{CH}_{2} ?\) (a) \(\mathrm{SOCl}_{2} ; \mathrm{H}_{2} \mathrm{O}\) (b) \(\mathrm{SO}_{2} \mathrm{Cl}_{2} ;\) alc. \(\mathrm{KOH}\) (c) \(\mathrm{Cl}_{2} / \mathrm{hv} ; \mathrm{H}_{2} \mathrm{O}\) (d) \(\mathrm{SOCl}_{2} ;\) alc. \(\mathrm{KOH}\)

An alkene on reductive ozonolysis gives two molecules of \(\mathrm{CH}_{2}(\mathrm{CHO})_{2} .\) The alkene is (a) 2,4 -hexadiene (b) 1,3 -cyclohexadiene (c) 1,4 -cyclohexadiene (d) 1 -methyl-1, 3 -cyclopentadiene

\mathrm{\\{} 6 r o m i d e ~ i s ~ c o n v e r t e d ~ i n t o ~ e t h a n e ~ b y ~ h e a t i n g ~ i t ~ i n ~ a n ~ ether medium with (a) \(\mathrm{Al}\) (b) \(\mathrm{Zn}\) (c) \(\mathrm{Na}\) (d) \(\mathrm{Cu}\)

In the solvolysis of 3 -methyl-3-bromohexane, which of the following statements is not correct? (a) it involves carbocation intermediate (b) the intermediate involves sp \(^{2}\) carbon (c) polar solvents accelerates the reaction (d) it involves inversion of configuration

Which one of the following compounds would have the highest heat of hydrogenation? (a) \(\left(\mathrm{CH}_{3}\right)_{2} \mathrm{C}=\mathrm{C}\left(\mathrm{CH}_{3}\right)_{2}\) (b) \(\mathrm{H}_{3} \mathrm{C}-\mathrm{CH}_{2}-\mathrm{CH}=\mathrm{CH}_{2}\) (c) \(\mathrm{H}_{3} \mathrm{C}-\mathrm{CH}=\mathrm{CH}-\mathrm{CH}_{3}\) (d) \(\mathrm{H}_{2} \mathrm{C}=\mathrm{CH}_{2}\)

When 2 -methyl butan-1-ol is dehydrated to give an alkene, the preferred product is (a) but-1-ene (b) but-2-ene (c) 2 -methyl but-1-ene

A hydrocarbon of molecular formula, \(\mathrm{C}_{8} \mathrm{H}_{18}\) gives only one monochloro derivative. The hydrocarbon is (a) 2 -methyl heptane (b) octane (c) \(2,2,3,3\)-tetramethyl butane (d) \(2,2,4\)-trimethyl pentane

Chloroethane reacts with magnesium in dry ether to form \(\mathrm{X}\). When \(\mathrm{X}\) is hydrolyzed, a carbon compound \(\mathrm{Y}\) and \(Z\) are formed. Which of the following is \(Y ?\) (a) \(\mathrm{C}_{2} \mathrm{H}_{4}\) (b) \(\mathrm{C}_{2} \mathrm{H}_{2}\) (c) \(\mathrm{C}_{2} \mathrm{H}_{6}\) (d) \(\mathrm{C}_{6} \mathrm{H}_{6}\)

Which one of the following compound yields only one product on monobromination? (a) neopentane (b) aniline (c) phenol (d) toluene

vA hydrocarbon of molecular formula \(\mathrm{C}_{7} \mathrm{H}_{12}\) on catalytic hydrogenation over platinum gives \(\mathrm{C}_{7} \mathrm{H}_{16} .\) The parent hydrocarbon adds bromine and also reacts with \(\left[\mathrm{Ag}\left(\mathrm{NH}_{3}\right)_{2}\right] \mathrm{OH}\) to give a precipitate. The parent hydrocarbon is (a) \(\left(\mathrm{CH}_{2}\right)_{3} \mathrm{CCH}_{2} \mathrm{C} \equiv \mathrm{CH}\) (b) \(\mathrm{CH}_{3} \mathrm{CH}=\mathrm{CHCH}_{2} \mathrm{CH}=\mathrm{CH}_{2}\) (c) \(\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{C} \equiv \mathrm{CHCH}\left(\mathrm{CH}_{3}\right)_{2}\) (d) \(\mathrm{CH}_{2} \mathrm{CH}^{2}=\mathrm{CHCH}=\mathrm{CHCH}_{2}\)

In order to obtain trans \(\mathrm{Me}-\mathrm{CH}=\) CH-Me from \(\mathrm{MeC}=\mathrm{CMe}\), the reagent(s) to be used would includes (a) \(\mathrm{LiAlH}_{4}\) in \(\mathrm{EtO}_{2}\) (b) \(\mathrm{H}_{2} / \mathrm{Pd}, \mathrm{BaSO}_{4}\) (c) \(\mathrm{H}_{2}^{2} / \mathrm{Pd}, \mathrm{Pb}(\mathrm{OAc})_{2}\) (d) sodium in liquid ammonia or sodium in \(\mathrm{EtOH}\)

Cold and dil. \(\mathrm{KMnO}_{4}\) combines with but-2-yne to form (a) butane-1, 3 -diol (b) butane-2, 3 -diol (c) butane-2, 3 -dione (d) butan-2-one

A hydrocarbon \(\mathrm{C}_{6} \mathrm{H}_{12}\) decolourizes bromine solution and yields n-hexane on hydrogenation. On oxidation with \(\mathrm{KMnO}_{4}\) it forms two different monobasic acids of the type RCOOH. The compound is (a) hex-2-ene (b) hex-3-ene (c) cyclohexene (d) hex-1-ene

The most reactive species among the followin towards sulphonation is (a) toluene (b) nitrobenzene (c) 1,3 -dimethyl benzene (d) chlorobenzene

\(18 \mathrm{C}-\mathrm{H}\) and \(7 \mathrm{C}-\mathrm{C}\) sigma bonds are present in (a) n-heptane (b) cyclohexane (c) 3,3 -dimethyl pentane (d) \(2,2,3\)-trimethyl pentane

Match the following: List I List II (Petroleum fractions) \(\quad\) (Approximate composition) 1\. gasoline (i) \(\mathrm{C}_{10}\) to \(\mathrm{C}_{15}\) 2\. kerosene (ii) \(\mathrm{C}_{6}\) to \(\mathrm{C}_{8}\) 3\. lubricating oil (iii) \(\mathrm{C}_{30}\) to \(\mathrm{C}_{40}\) 4\. pitch and asphalt (iv) \(\mathrm{C}_{17}\) to \(\mathrm{C}_{20}\) The correct matching is: 1 \(\begin{array}{lll}2 & 3 & 4\end{array}\) (a) (ii) (i) (iii) (iv) (b) (i) (iii) (iv) (ii) (c) (i) (ii) (iv) (iii) (d) (ii) (i) (iv) (iii)

Cyclooctatetraene is not aromatic. The most important reason for this is that (a) it is a planar molecule (b) it has eight \(\pi\)-electrons (c) its structure cannot be described by more than the canonical forms (d) its structure is not that of regular octagon

Which of the following reactions will yield 2 2-dibromopropane? (a) \(\mathrm{CH}_{3} \mathrm{CH}=\mathrm{CHBr}+\mathrm{HBr} \longrightarrow\) (b) \(\mathrm{HC} \equiv \mathrm{CH}+2 \mathrm{HBr} \longrightarrow\) (c) \(\mathrm{CH}_{3} \mathrm{CH}=\mathrm{CH}_{2}+\mathrm{HBr} \longrightarrow\) (d) \(\mathrm{CH}_{3} \mathrm{C} \equiv \mathrm{CH}+2 \mathrm{HBr} \longrightarrow\)

Match the following: List I List II 1\. benzene (i) phosgene 2\. ethylene (ii) silver mirror 3\. acetaldehyde (iii) mustard gas 4\. chloroform (iv) \((4 \mathrm{n}+2) \pi\)-electrons (v) carbylamine The correct matching is: \(1 \quad 2\) \(3 \quad 4\) (a) (iv) (iii) (i) (ii) (b) (iv) (iii) (ii) (i) (c) (iii) (iv) (ii) (i) (d) (ii) (i) (iv) (iii)

Ozonolysis of 2,3 -dimethyl-1-butene followed by reduction with zinc and water gives (a) methanoic acid and 3-methyl-2-butanone (b) methanal and 3 -methyl-2-butanone (c) methanal and 2-methyl-3-butanone (d) methanoic acid and 2-methyl-3-butanone

The number of structural and configurational isomers of a bromo compound, \(\mathrm{C}_{5} \mathrm{H}_{9} \mathrm{Br}\), formed by the addition of HBr to 2 -pentyne respectively are (a) 1 and 2 (b) 2 and 4 (c) 4 and 2 (d) 2 and 1

Compare the \(\mathrm{C}-\mathrm{H}\) bond lengths of the following hydrocarbons: 1\. \(\mathrm{CH}_{3}-\mathrm{CH}_{3}\) 2\. \(\mathrm{CH}_{2}=\mathrm{CH}_{2}\) 3\. \(\mathrm{CH} \equiv \mathrm{CH}\)The decreasing order of \(\mathrm{C}-\mathrm{H}\) bond lengths is \(\begin{array}{ll}\text { (a) } 3,2,1 & \text { (b) } 1,23\end{array}\) (c) \(2,1,3\)

A hydrocarbon \(\mathrm{C}_{6} \mathrm{H}_{10}\) does not react with ammonical solution of \(\mathrm{Cu}^{+}\)ions; it adsorbs \(2 \mathrm{~mol}\) of hydrogen on catalytic hydrogenation to give 2 -methylpentane. The hydrocarbon adds one molecule of water on treatment with \(\mathrm{Hg}^{2+} / \mathrm{H}_{2} \mathrm{SO}_{4}\). The structure of given compound is (a) \(\mathrm{H}_{2} \mathrm{C}=\mathrm{CH}-\mathrm{CH}=\mathrm{C}\left(\mathrm{CH}_{3}\right)_{2}\) (b) \(\mathrm{H}_{3} \mathrm{C}-\mathrm{C} \equiv \mathrm{C}-\mathrm{CH}\left(\mathrm{CH}_{3}\right)_{2}\) (c) C=C=CC(=C)C (d) \(\mathrm{HC}=\mathrm{C}-\mathrm{CH}_{2}-\mathrm{CH}\left(\mathrm{CH}_{3}\right)_{2}\)

Among the following compounds which has more than one type of hybridization for carbon atom? I. \(\mathrm{CH}_{3} \cdot \mathrm{CH}_{2} \cdot \mathrm{CH}_{2} \cdot \mathrm{CH}_{3}\) II. \(\mathrm{CH}_{3} \cdot \mathrm{CH}^{2}=\mathrm{CH}^{2} \cdot \mathrm{CH}_{3}\) III. \(\mathrm{CH}_{2}=\mathrm{CH}-\mathrm{C} \equiv \mathrm{CH}\) IV. \(\mathrm{CH}_{2}=\mathrm{CH}_{2}\) (a) II only (b) II and III (c) I and III (d) III and IV

Match the following: List I List II 1\. ethane (i) 2 sp carbons 2\. ethylene (ii) \(6 \mathrm{sp}^{2}\) carbons 3\. acetylene (iii) \(2 \mathrm{sp}^{3}\) carbons 4\. benzene (iv) \(2 s p^{2}\) carbons (v) \(1 \mathrm{sp}\) and \(1 \mathrm{sp}^{2}\) carbons

The heat of hydrogenation of benzene is \(51 \mathrm{kcal} / \mathrm{mol}\) and its resonance energy is \(36 \mathrm{kcal} / \mathrm{mol}\). Then the heats of hydrogenation of cyclohexadiene and cyclohexene are respectively (a) \(58 \mathrm{kcal}, 29 \mathrm{kcal}\) (b) \(28 \mathrm{kcal}, 59 \mathrm{kcal}\) (c) \(58 \mathrm{kcal}, 49 \mathrm{kcal}\) (d) \(29 \mathrm{kcal}, 48 \mathrm{kcal}\)