Chapter 25

What will be the product in the following reaction? NBS (a) CC1CCCCC1Br (b) CC1CCC(Br)CC1

Chlorobenzene can be prepared by reacting aniline with (a) nitrous acid followed by heating with cuprous chloride (b) chlorine in presence of anhydrous aluminium chloride (c) cuprous chloride (d) hydrochloric acid

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

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

In the presence of peroxide, and hydrogen chloride, hydrogen iodide does not undergo antiMarkovnikov's addition to alkenes because (a) both are highly ionic (b) one is oxidizing and other is reducing (c) one of the steps is endothermic in both the cases (d) all the steps are exothermic in both the cases

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 product(s) obtained via oxymercuration \(\left(\mathrm{HgSO}_{4}\right.\) \(+\mathrm{H}_{2} \mathrm{SO}_{4}\) ) of but-1-yne would give (a) CCC(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) \(\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{COOH}+\mathrm{HCOOH}\)

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

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 \(\ldots . .\) 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) \(\mathrm{SOCl}\), 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

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 (d) 2-methyl but-2-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 \(X\). When \(X\) is hydrolyzed, a carbon compound \(Y\) and \(\mathrm{Z}\) are formed. Which of the following is \(\mathrm{Y}\) ? (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

A 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) \(\left(\mathrm{CH}_{3}\right)_{3} \mathrm{CCH}_{2} \mathrm{C} \equiv \mathrm{CH}\) (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) \(\mathrm{CH}_{3} \mathrm{CH}^{2}=\mathrm{CHCH}=\mathrm{CHCH}_{3}\)

In order to obtain trans \(\mathrm{Me} \mathrm{CH}=\mathrm{CH}-\mathrm{Me}\) from \(\mathrm{MeC} \equiv \mathrm{CMe}\), 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) \(\mathrm{H}_{2} / \mathrm{Pd}, \mathrm{Pb}(\mathrm{OAc})_{2}\) (d) sodium in liquid ammonia or sodium in 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

The products formed by the ozonolysis-hydrolysis of a compound of formula, \(\mathrm{C}_{5} \mathrm{H}_{8}\) are \(\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{COOH}\) and \(\mathrm{CO}_{2}\). The compound is (a) pent-2-yne (b) pent-1-yne (c) penta-1, 3-diene (d) penta-1, 4-diene

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 \(\mathrm{RCOOH}\). The compound is (a) hex-2-ene (b) hex-3-ene (c) cyclohexene (d) hex-1-ene

The ozonolysis of 1,2 -dimethyl benzene (o-xylene) gives (a) methyl glyoxal (b) glyoxal (c) dimethyl glyoxal (d) all the three above

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

Match the following: List I List II (Petroleum fractions) (Approximate composition) 1\. gasoline (i) \(\mathrm{C}_{10}\) to \(\mathrm{C}_{15}\) 2\. kerosene \(\quad\) (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: \(\begin{array}{lll}1 & 2 & 3\end{array}\) 4 (a) (ii) (i) (iii) (iv) (b) (i) (ii) (iv) (ii) \(\begin{array}{llll}\text { (c) (i) } & \text { (ii) } & \text { (iv) (iii) }\end{array}\) (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-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) \(\mathrm{CH}_{2} \mathrm{C} \equiv \mathrm{CH}+2 \mathrm{HBr} \longrightarrow\)

Toluene reacts with methyl chloride in presence of anhydrous aluminium chloride to form mainly m-xylene. This is because (a) \(\mathrm{CH}_{3}\) - group has +I effect (b) \(\mathrm{CH}_{3}-\) group is meta directing (c) m-xylene is thermodynamically most stable of the other xylenes (d) hyperconjugation effect of \(\mathrm{CH}_{3}\) - group

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 \(\mathrm{HBr}\) 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\. \(\mathrm{CH} \equiv \mathrm{CH}\)

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=CCC(C)C (d) \(\mathrm{HC} \equiv \mathrm{C}-\mathrm{CH}_{2}-\mathrm{CH}\left(\mathrm{CH}_{3}\right)_{2}\)

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: \(\begin{array}{ll}\text { List I } & \text { List II }\end{array}\) 1\. ethane (i) \(2 \mathrm{sp}\) carbons 2\. ethylene (ii) \(6 \mathrm{sp}^{2}\) carbons 3\. acetylene (iii) \(2 \mathrm{sp}^{3}\) carbons 4\. benzene (iv) \(2 \mathrm{sp}^{2}\) carbons (v) 1 sp and \(1 \mathrm{sp}^{2}\) carbons The correct matching is: \(\begin{array}{lll}1 & 2 & 3\end{array}\) 4 (a) (ii) (iii) (iv) (v) (b) (iii) (i) (ii) (v) (c) (iv) (v) (iii) (ii) (d) (iii) (iv) (i) (ii)

Consider the following alkenes: 1\. \(\mathrm{H}_{2} \mathrm{C}=\mathrm{C}\left(\mathrm{CH}_{2} \mathrm{CH}_{3}\right) \mathrm{CH}\left(\mathrm{CH}_{3}\right)_{2}\) 2\. \(\left(\mathrm{CH}_{3}\right)_{2} \mathrm{C}=\mathrm{C}\left(\mathrm{CH}_{3}\right) \mathrm{CH}_{2} \mathrm{CH}_{3}\) 3\. \(\mathrm{CH}_{3} \mathrm{CH}=\mathrm{C}\left(\mathrm{CH}_{3}\right) \mathrm{CH}\left(\mathrm{CH}_{3}\right)_{2}\) The correct sequence of increasing order of stability of these alkenes is (a) \(3,1,2\) (b) \(1,3,2\) (c) \(1,2,3\) (d) \(2,1,3\)

Consider the following compounds: 1\. \(\mathrm{CH}_{3}-\mathrm{CH}_{2}-\mathrm{CHCl}-\mathrm{CH}_{3}\) 2\. \(\mathrm{CH}_{2}=\mathrm{CH}-\mathrm{CH}_{2}-\mathrm{CH}_{2} \mathrm{Cl}\) 3\. \(\mathrm{CH}_{3}-\mathrm{CH}_{2}-\mathrm{CH}_{2}-\mathrm{CH}_{2} \mathrm{Cl}\) These compounds are dehydrohalogenated by treatment with a strong base under identical conditions. The correct sequence of the increasing order of reactivity of these compounds in the given reaction is (a) \(3,1,2\) (b) \(3,2,1\) (c) \(1,2,3\) (d) \(2,1,3\)

Consider the following compounds: 1\. \(\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{OH}\) 2\. \(\mathrm{CH}_{3} \mathrm{CH}_{2}^{2} \mathrm{CH}(\mathrm{OH}) \mathrm{CH}_{3}\) 3\. \(\left(\mathrm{CH}_{3}\right)_{3} \mathrm{COH}\) These compounds are dehydrated by treatment with sulphuric acid. The correct sequence of increasing order of the reactivity of these three compounds towards dehydration is (a) \(1,3,2\) (b) \(1,2,3\) (c) \(2,1,3\) (d) \(3,1,2\)

Consider the given statements about the molecule \(\left(\mathrm{H}_{3} \mathrm{C}\right)_{2} \mathrm{CH}-\mathrm{CH}=\mathrm{CH}-\mathrm{C} \equiv \mathrm{C}-\mathrm{CH}=\mathrm{CH}_{2}\) 1\. three carbons are sp \(^{3}\) hybridized 2\. three carbons are sp \(^{2}\) hybridized 3\. two carbons are sp hybridized Of these statements (a) 1 and 2 are correct (b) 1 and 3 are correct (c) 2 and 3 are correct (d) all are correct

The products formed when bromocylohexane and sodium propynide are heated together are (a) cyclohexene (b) 2 - cyclohexyl propyne (c) propyne (d) 1 - cyclohexyl propene

Consider the following reaction, CC1=CC(=O)CCC1 \(\frac{\text { (i) } \mathrm{NaNH}_{2}(2 \mathrm{eq})}{\text { (ii) } \mathrm{Br}\left(-\mathrm{CH}_{2}-\mathrm{O}_{3} \mathrm{Br}\right)}\) Products Probable products of the above reaction would be (a) CC1=CCCC2=C1CCCO2 (b) C=C1CCCC2=C1CCCO2 (c) CC1=CCCC(=O)C1C (d) C=C1CCCC(=O)C12CC2

Which of the following statement is/are correct? (a) \(\mathrm{H}_{2} \mathrm{C}=\mathrm{CH}_{2}+\mathrm{H}_{2} \stackrel{N i}{\longrightarrow}\) product; the rate of reac- tion is \(\mathrm{k}_{1}\). \(\mathrm{HC} \equiv \mathrm{CH}+\mathrm{H}_{2} \stackrel{N i}{\longrightarrow}\) product; the rate of reaction is \(\mathrm{k}_{2}\). Then \(\mathrm{k}_{2}>\mathrm{k}_{1}\) (b) Dehydration of alcohol is equally facilitated in acid as in basic medium. (c) The trans stereoisomer is formed when cyclohexene is brominated in presence of \(\mathrm{CCl}_{4}\). (d) ClC(Cl)CC1(Br)CCCC1

In which of the following case(s), the product contains a cyclopentene ring? (Consider the major product). C=C1CCCC1 (a) (b) BrCC1CCC1 (c) OC1CCCC1 BrCC1CCC1 (d)

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

Which one of the following reactions gives a secondary alcohol? (a) \(\mathrm{CH}_{3}-\mathrm{CH}=\mathrm{CH}_{2} \frac{\text { peroxide }}{\mathrm{HBr}} \stackrel{\mathrm{H}_{2} \mathrm{O}, \mathrm{OH}^{-}}{\longrightarrow}\) (b) \(\mathrm{CH}_{3}-\mathrm{CH}=\mathrm{CH}_{2} \frac{\text { (i) } \mathrm{BH}_{3}(\mathrm{THF})}{\text { (ii) } \mathrm{H}_{2} \mathrm{O}_{2}, \mathrm{OH}^{-}}\) (c) \(\mathrm{CH}_{3}-\mathrm{CH}=\mathrm{CH}_{2} \stackrel{\mathrm{H}_{3} \mathrm{SO}_{4}}{\mathrm{H}_{2} \mathrm{O}}\) (d) \(\underbrace{\mathrm{CH}_{2}-\mathrm{CH}_{2}}_{\mathrm{O}} \frac{\text { (i) } \mathrm{CH}_{3} \mathrm{MgBr}}{\text { (ii) } \mathrm{H}_{3} \mathrm{O}^{+}}\)

Identify the product of the following reaction. \(\mathrm{CH}_{3}-\mathrm{CH}\left(\mathrm{CH}_{3}\right)-\mathrm{CH}=\mathrm{CH}_{2} \frac{\mathrm{H}^{+}}{\mathrm{H}_{2} \mathrm{O}} \rightarrow\) Product (a) CC(C)C(C)O (b) \(\mathrm{CH}_{3}-\mathrm{CH}\left(\mathrm{CH}_{3}\right)-\mathrm{CH}_{2}-\mathrm{CH}_{2} \mathrm{OH}\)

Match the following \begin{tabular}{ll} \hline Column-I & Column-II \\ \hline (a) Hydrocarboration of & (p) Primary alcohol \\ simplest unsaturated & \\ hydrocarbon followed & \\ by \(\mathrm{H}^{+} .\) & \\ \(\begin{array}{ll}\text { (b) Red } \mathrm{P} / \mathrm{HI} \text { reduces. } & \text { (q) Alkane } \\ \text { (c) Reductive ozonlysis } & \text { (r) Aldehyde } \\ \text { (d) Pyrolysis of xanthate } & \text { (s) Alkene } \\ & \text { (t) Reaction has syn } \\ \text { stereochemistry }\end{array}\) \end{tabular}

vMatch the followingColumn-I (a) Benzene (b) Neopentane (c) Buta - 1, 3 -diene (d) \(2,2,3,3\) - Tetramethyl butaneColumn-II (p) Forms only one mono chloro derivative (q) Aromatic (r) Has only sp \(^{2}\) hybridised carbon atoms (s) Undergoes 1,2 and 1,4 -addition (t) Does not show resonance