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

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) \(\mathrm{C}_{6}^{2} \mathrm{H}_{6}^{6}\) (d) \(\mathrm{C}_{2} \mathrm{H}_{3}\)

\(\mathrm{CHCOONa}\) Eletmlyais \(\rightarrow[\mathrm{A}] \frac{\mathrm{L}_{2}}{\text { liquid } \mathrm{NH}_{3}} \rightarrow[\mathrm{B}]\) Here, [B] is (a) \(\mathrm{CH}=\mathrm{CH}\) (b) \(\mathrm{NaC}=\mathrm{CNa}\) (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) \(\mathrm{COCl}_{2}^{2}\)

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

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

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) \(\mathrm{CH}_{3} \mathrm{CH}_{2}^{->} \mathrm{NH}_{2}^{-}>\mathrm{HC} \equiv \mathrm{C}^{-}>\mathrm{OH}^{-}\) (b) \(\mathrm{HC} \equiv \mathrm{C}^{-}>\mathrm{CH}_{3} \mathrm{CH}_{2}^{-}>\mathrm{NH}_{2}^{-}>\mathrm{OH}^{-}\) (c) \(\mathrm{OH}^{-}>\mathrm{NH}_{2}^{-}>\mathrm{HC} \equiv \mathrm{C}^{-}>\mathrm{CH}_{3} \mathrm{CH}_{2}^{-}\) (d) \(\mathrm{NH}_{2}^{-}>\mathrm{HC} \equiv \mathrm{C}^{-}>\mathrm{OH}^{-}>\mathrm{CH}_{3} \mathrm{CH}_{2}^{-}\)

\(\mathrm{Ph}-\mathrm{C} \equiv \mathrm{C}-\mathrm{CH}_{3} \stackrel{\mathrm{Hg}_{B}^{+2} / \mathrm{H}^{+}}{\longrightarrow}\) A. Here, \(\mathrm{A}\) is

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) \(\mathrm{CH}_{3} \mathrm{COOH}+\mathrm{HOOC} \cdot \mathrm{CH}_{2} \mathrm{CH}_{3}\) (c) \(\mathrm{CH}_{3} \mathrm{CHO}+\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CHO}\) (d) \(\mathrm{CH}_{3} \mathrm{COOH}+\mathrm{CH}_{3} \mathrm{COCH}_{3}\)

Wurtz reaction of methyl iodide yields an organic compound \(\mathrm{X}\). Which one of he following reactions also yields X? (a) \(\mathrm{CHCl}_{3} \stackrel{\text { Ag powder, } \triangle}{\longrightarrow}\) (b) \(\mathrm{C}_{2} \mathrm{H}_{5} \mathrm{Cl}+\mathrm{C}_{2} \mathrm{H}_{5} \mathrm{ONa} \longrightarrow\) (c) \(\mathrm{C}_{2} \mathrm{H}_{5} \mathrm{Cl}+\mathrm{LiAlH}_{4} \longrightarrow\) (d) \(\mathrm{C}_{2} \mathrm{H}_{5} \mathrm{Cl}+\mathrm{Mg} \frac{\text { Dry ether }}{\longrightarrow}\)

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

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

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-l-yne would give

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) \(2,2,4\)

One mole of an unsaturated hydrocarbon on ozonolysis gives one mole each of \(\mathrm{CH}_{3} \mathrm{CHO}, \mathrm{HCHO}\) and OHC.CHO. The hydrocarbon is (a) \(\mathrm{CH}_{3} \cdot \mathrm{CH}_{2} \mathrm{C}=\mathrm{C} . \mathrm{CH}_{3}\) (b) \(\mathrm{CH}=\mathrm{C} \cdot \mathrm{CH}_{2} \cdot \mathrm{CH}_{2} \mathrm{CH}_{3}\) (c) \(\mathrm{CH}_{3} . \mathrm{CH}=\mathrm{CH} . \mathrm{CH}=\mathrm{CH}_{2}\) (d) \(\mathrm{CH}_{2}=\mathrm{CH} . \mathrm{CH}_{2} \cdot \mathrm{CH}=\mathrm{CH}_{2}\)

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

Bromide is converted into ethane by heating it in an 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 \(s p^{2}\) 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-l-ol is dehydrated to give an alkene, the preferred product is (a) but-I-ene (b) but-2-ene (c) 2 -methyl but-l-ene (d) 2-methyl but-2-ene

A hydrocarbon of molecular formula, \(\mathrm{C}_{\mathrm{s}} \mathrm{H}_{18}\) 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) \(\mathrm{C}_{2} \mathrm{H}\) (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) \(\left(\mathrm{CH}_{3}\right)_{3} \mathrm{CCH}_{2} \mathrm{C}=\mathrm{CH}\) (b) \(\mathrm{CH}_{3} \mathrm{CH}=\mathrm{CHCH}_{2} \mathrm{CH}=\mathrm{CH}_{2}\) (c) \(\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{C}=\mathrm{CHCH}\left(\mathrm{CH}_{3}\right)_{2}\) (d) \(\mathrm{CH}_{3} \mathrm{CH}=\mathrm{CHCH}=\mathrm{CHCH}_{3}\)

In order to obtain trans Me-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

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 RCOOH. The compound is (a) hex-2-ene (b) hex-3-ene (c) cyclohexene (d) hex-l-ene

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

\(18 \mathrm{C}-\mathrm{H}\) 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 (Petroleum fractions) 1\. gasoline 2\. kerosene 3\. lubricating oil 4\. pitch and asphalt The correct matching is: List II (Approximate composition) (i) \(\mathrm{C}_{10}\) to \(\overline{\mathrm{C}}_{15}\) (ii) \(\mathrm{C}_{6} \mathrm{to} \mathrm{C}_{8}\) (iii) \(\vec{C}_{30}\) to \(C_{40}\) (iv) \(\mathrm{C}_{17}\) to \(\mathrm{C}_{20}\)

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) \(\mathrm{HC}=\mathrm{CH}+2 \mathrm{HBr} \longrightarrow\) (c) \(\mathrm{CH}_{3} \mathrm{CH}=\mathrm{CH}_{2}+\mathrm{HBr} \longrightarrow\) (d) \(\mathrm{CH}_{3} \mathrm{C}=\mathrm{CH}+2 \mathrm{HBr} \longrightarrow\)

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 C-H bond lengths of the following hydrocarbons: 1\. \(\mathrm{CH}_{3}-\mathrm{CH}_{3}\) 2\. \(\mathrm{CH}_{2}=\mathrm{CH}_{2}\) 3\. \(\mathrm{CH}=\mathrm{CH}\) The decreasing order of \(\mathrm{C}-\mathrm{H}\) bond lengths is (a) \(3,2,1_{-}\) (b) \(1,2,3\) (c) \(2,1,3\) (d) \(3,1,2\)

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

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. \(\mathrm{CH}_{3} \cdot \mathrm{CH}=\mathrm{CH}^{2} \cdot \mathrm{CH}_{3}\) III. \(\mathrm{CH}_{2}=\mathrm{CH}-\mathrm{C}=\mathrm{CH}\) 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 1\. ethane 2\. ethylene 3\. acetylene 4\. benzene List II (i) 2 sp carbons (ii) \(6 \mathrm{sp}^{2}\) carbons (iii) \(2 \mathrm{sp}^{3}\) carbons (iv) \(2 \mathrm{sp}^{2}\) carbons (v) lsp and 1 sp \(^{2}\) carbons

The heat of hydrogenation of benzene is \(50 \mathrm{kcal} /\) mol. The resonance energy of benzene is \(36 \mathrm{kcal} /\) mol. The heat of hydrogenation of cyclohexene is approximately (a) \(9 \mathrm{kcal} / \mathrm{mol}\) (b) \(19 \mathrm{kcal} / \mathrm{mol}\) (c) \(29 \mathrm{kcal} / \mathrm{mol}\) (d) \(27 \mathrm{kcal} / \mathrm{mol}\)

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\. \(\mathrm{CH}_{3} \mathrm{CH}=\mathrm{C}\left(\mathrm{CH}_{3}\right) \mathrm{CH}\left(\mathrm{CH}_{3}\right)_{2}^{5}\) 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\. \(\mathrm{CH}_{2}=\mathrm{CH}^{2}-\mathrm{CH}_{2}-\mathrm{CH}_{2} \mathrm{Cl}\) 3\. \(\mathrm{CH}_{3}-\mathrm{CH}_{2}-\mathrm{CH}_{2}-\mathrm{CH}_{2}^{2} \mathrm{Cl}\) 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\. \(\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CH}(\mathrm{OH}) \mathrm{CH}_{3}\) 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) \(3,1,2\)