Chapter 26

Wurtz reaction involves the reduction of alkyl halide with (a) HI (b) \(\mathrm{Zn} / \mathrm{HCl}\) (c) \(\mathrm{Zn}\) in an inert solvent (d) Na in ether

Which of the following compound reacts with chlorobenzene to produce DDT? (a) trichloroacetaldehyde (b) m-chloroacetaldehyde (c) acetaldehyde (d) nitrobenzene

Chloroform is slowly oxidized by air in the presence of light and air to form (a) phosgene (b) formyl chloride (c) formaldehyde (d) trichloroethanol

The end product [B] in the following sequence of reactions is \(\mathrm{CH}_{3} \mathrm{Cl} \stackrel{\mathrm{KCN}}{\longrightarrow}[\mathrm{A}] \stackrel{\mathrm{H}^{\prime} / \mathrm{H}_{2} \mathrm{O}}{\longrightarrow}[\mathrm{B}]\) (a) \(\mathrm{HCOOH}\) (b) \(\mathrm{CH}_{3} \mathrm{COCH}_{3}\) (c) \(\mathrm{CH}_{3} \mathrm{NH}_{2}\) (d) \(\mathrm{CH}_{3} \mathrm{COOH}\)

\(\mathrm{CH}_{3}-\mathrm{CH}_{2}-\mathrm{CH}_{2}-\mathrm{Cl} \stackrel{\text { alc. } \mathrm{KOH}}{\longrightarrow}(\mathrm{X}) \stackrel{\mathrm{HBr}}{\longrightarrow}(\mathrm{Y}) \stackrel{\mathrm{Na} / \mathrm{cther}}{\longrightarrow}(\mathrm{Z})\) In the above sequence of reaction, the product \((Z)\) is (a) propane (b) hexane (c) 2,3 -dimethylbutane (d) allyl bromide

\(\mathrm{R}-\mathrm{OH}+\mathrm{HX} \longrightarrow \mathrm{R}-\mathrm{X}+\mathrm{H}_{2} \mathrm{O}\) In the above reaction, the reactivity of different alcohols is (a) tertiary \(>\) secondary \(>\) primary (b) tertiary \(>\) secondary \(<\) primary (c) tertiary < secondary \(>\) primary (d) secondary < primary < tertiary

Under which of the following conditions would toluene \(\mathrm{C}_{6} \mathrm{H}_{5}-\mathrm{CH}_{3}\), be converted into bromomethyl benzene, \(\mathrm{C}_{6} \mathrm{H}_{3}-\mathrm{CH}_{2} \mathrm{Br}\) ? (a) reaction with \(\mathrm{Br}_{2}\) in dark (b) reaction with \(\mathrm{Br}_{2} / \mathrm{FeBr}_{3}\) (c) reaction with \(\mathrm{Br}_{2}\) in sunlight (d) reaction with \(\mathrm{HBr}\)

The number of isomeric alkyl halides possible for \(\mathrm{C}_{5} \mathrm{H}_{11} \mathrm{Cl}\) is (a) 5 (b) 6 (c) 4 (d) 8

Chlorination of toluene in the presence of light and heat followed by treatment with aqueous NaOH gives (a) p-cresol (b) o-cresol (c) benzoic acid (d) 2,4 -dihydroxytoluene

The reaction of benzyl chloride with sodium cyanide followed by reduction with hydrogen in the presence of nickel gives (a) \(\mathrm{n}\)-isobutylaniline (b) \(\beta\)-phenylethylamine (c) aniline (d) benzylamine

Identify \(\mathrm{Z}\) in the following series: \(\mathrm{C}_{2} \mathrm{H}_{5} \mathrm{I} \stackrel{\text { Alc. } \mathrm{KOH}}{\longrightarrow} \mathrm{X} \stackrel{\mathrm{Br}_{2}}{\longrightarrow} \mathrm{Y} \stackrel{\mathrm{KCN}}{\longrightarrow} \mathrm{Z}\) (a) \(\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CN}\) (b) \(\mathrm{NCCH}_{2}-\mathrm{CH}_{2} \mathrm{CN}\) (c) \(\mathrm{BrCH}_{2}-\mathrm{CH}_{2} \mathrm{CN}\) (d) \(\mathrm{BrCH}=\mathrm{CHCN}\)

Which of the following represents the correct order of densities? (a) \(\mathrm{CCl}_{4}>\mathrm{CHCl}_{3}>\mathrm{CH}_{2} \mathrm{Cl}_{2}>\mathrm{CH}_{3} \mathrm{Cl}>\mathrm{H}_{2} \mathrm{O}\) (b) \(\mathrm{CCl}_{4}>\mathrm{CHCl}_{3}>\mathrm{CH}_{2} \mathrm{Cl}_{2}>\mathrm{H}_{2} \mathrm{O}>\mathrm{CH}_{3} \mathrm{Cl}\) (c) \(\mathrm{H}_{2} \mathrm{O}>\mathrm{CH}_{3} \mathrm{Cl}>\mathrm{CH}_{2} \mathrm{Cl}_{2}>\mathrm{CHCl}_{3}>\mathrm{CCl}_{4}\) (d) \(\mathrm{CCl}_{4}>\mathrm{CHCl}_{3}>\mathrm{H}_{2} \mathrm{O}>\mathrm{CH}_{2} \mathrm{Cl}_{2}>\mathrm{CH}_{3} \mathrm{Cl}\)

The compound \(\mathrm{C}\) in the following is sequence: \(\mathrm{C}_{7} \mathrm{H}_{8} \stackrel{3 \mathrm{Cl}_{2} / \Delta}{\longrightarrow} \mathrm{A} \stackrel{\mathrm{Br}_{2} / \mathrm{Fe}}{\longrightarrow} \mathrm{B} \stackrel{\mathrm{Zn} / \mathrm{HCl}}{\longrightarrow} \mathrm{C}\) (a) p-bromotoluene (b) o-bromotoluene (c) m-bromotoluene (d) 3 -bromo-2, 4,6 -trichlorotoluene

\(\mathrm{CH}_{3} \mathrm{CH}=\mathrm{CH}_{2} \stackrel{\mathrm{Cl}_{2}(\mathrm{hv})}{\longrightarrow} \mathrm{X} \stackrel{\mathrm{Nal}}{\longrightarrow} \mathrm{Y}\) The compound \(\mathrm{Y}\) in the above sequence is (a) 3-iodopropene (b) 1,2 -diodopropane (c) 1,2 -dichloro-3-iodopropane (d) 1 -chloro-2-iodopropane

Iodoform on heating with KOH gives (a) \(\mathrm{CH}_{3} \mathrm{COOK}\) (b) HCOOK (c) HCHO (d) \(\mathrm{CH}_{3} \mathrm{CHO}\)

When chlorine is passed through propene at \(400^{\circ} \mathrm{C}\), which of the following is formed? (a) allyl chloride (b) PVC (c) vinyl chloride (d) 1,2 -dichloroethane

\(\left(\mathrm{CH}_{3}\right)_{3} \mathrm{C}-\mathrm{Cl} \stackrel{\mathrm{Acl}_{\mathrm{K} \mathrm{OH}}}{\Delta} \longrightarrow \mathrm{A} \frac{\mathrm{SO}_{2} \mathrm{Cl}_{2}}{475 \mathrm{~K}}{\longrightarrow} \mathrm{B}\) The compound B in the above sequence is (a) 1,2 -dichloro-2-methyl propene (b) 1 -chloro-2-methyl propene (c) 1,2 -dichloro-2-methyl propene (d) 3 -chloro-2-methyl propene

An alkyl chloride produces a single alkene on reaction with sodium ethoxide and ethanol. The alkene further undergoes hydrogenation to yield 2-methylbutane. Identify the alkyl chloride from amongst the following. (a) \(\mathrm{ClCH}_{2} \mathrm{CH}\left(\mathrm{CH}_{3}\right) \mathrm{CH}_{2} \mathrm{CH}_{3}\) (b) \(\mathrm{ClCH}_{2} \mathrm{C}\left(\mathrm{CH}_{3}\right)_{2} \mathrm{CH}_{3}\) (c) \(\mathrm{ClCH}_{2} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{CH}_{3}^{3}\) (d) \(\mathrm{CH}_{3} \mathrm{C}(\mathrm{Cl})\left(\mathrm{CH}_{3}\right) \mathrm{CH}_{2} \mathrm{CH}_{3}\)

A set of compounds in which the reactivity of halogen atom in the ascending order is (a) chloroethane, chlorobenzene, vinyl chloride (b) chlorobenzene, vinyl chloride, chloroethane (c) vinyl chloride, chloroethane, chlorobenzene (d) vinyl chloride, chlorobenzene, chloroethane

In the following groups: 1\. \(-\mathrm{OAc}\) 2\. - OMe 3\. \(-\mathrm{OSO}_{2} \mathrm{Me}\) 4\. \(-\mathrm{OSO}_{2} \mathrm{CF}_{3}\) the order of leaving group ability is (a) \(1>2>3>4\) (b) \(4>3>1>2\) (c) \(4>2>1>3\) (d) \(2>3>4>1\)

At higher temperature, iodoform reaction is given by (a) \(\mathrm{CH}_{3} \mathrm{CO}_{2} \mathrm{CH}_{3}\) (b) \(\mathrm{CH}_{3} \mathrm{CO}_{2} \mathrm{C}_{6} \mathrm{H}_{5}\) (c) \(\mathrm{CH}_{3} \mathrm{CO}_{2} \mathrm{C}_{2} \mathrm{H}_{5}\) (d) \(\mathrm{C}_{6} \mathrm{H}_{5} \mathrm{CO}_{2} \mathrm{CH}_{3}\)

Allyl chloride on dehydrochlorination gives (a) propylene (b) acetone (c) propadiene (d) allyl alcohol

Identify \(Z\) in the following series: \(\mathrm{CH}_{2}=\mathrm{CH}_{2} \stackrel{\mathrm{HBr}}{\longrightarrow} \mathrm{X} \stackrel{\text { Hydrolysis }}{\longrightarrow} \mathrm{Y} \stackrel{\mathrm{I}_{2} \text { Excess }}{\longrightarrow} \mathrm{Z}\) (a) \(\mathrm{CHI}_{3}\) (b) \(\mathrm{CH}_{3} \mathrm{CHO}\) (c) \(\mathrm{C}_{2} \mathrm{H}_{5} \mathrm{I}\) (d) \(\mathrm{C}_{2} \mathrm{H}_{5} \mathrm{OH}\)

The order of reactivities of the following alklyl halides for a \(\mathrm{S}_{\mathrm{N}}^{2}\) reaction is (a) \(\mathrm{RF}>\mathrm{RCl}>\mathrm{RBr}>\mathrm{RI}\) (b) \(\mathrm{RF}>\mathrm{RBr}>\mathrm{RCl}>\mathrm{RI}\) (c) \(\mathrm{RCl}>\mathrm{RBr}>\mathrm{RF}>\mathrm{RI}\) (d) \(\mathrm{RI}>\mathrm{RBr}>\mathrm{RCl}>\mathrm{RF}\)

During debromination of meso-dibromobutane, the major compound formed is (a) \(\mathrm{n}\)-butane (b) 1 -butane (c) cis-2-butene (d) trans-2-butene

Arrange the following compounds in order of increasing dipole moment I. toluene, II. \(\mathrm{m}\)-dichlorobenzene, III. o-dichlorobenzene, and IV. p-dichlorobenzene. (a) \(\mathrm{I}<\mathrm{IV}<\mathrm{II}<\mathrm{III}\) (b) IV \(<\mathrm{I}<\mathrm{II}<\mathrm{III}\) (c) IV \(<\mathrm{I}<\mathrm{III}<\mathrm{II}\) (d) \(\mathrm{IV}<\mathrm{II}<\mathrm{I}<\mathrm{III}\)

The products formed when alcoholic silver nitrile reacts with ethyl bromide are 1\. ethyne 2\. ethene 3\. nitroethane 4\. ethyl alcohol 5\. ethyl nitrile (a) 3,5 (b) 3,4 (c) \(2,3,5\) (d) 1,5

1-chlorobutane on reaction with alcoholic potash gives (a) 1 -butene (b) 1 -butanol (c) 2-butene (d) 2-butanol

n-propyl bromide on treatment with ethanolic potassium hydroxide produces (a) propane (b) propene (c) propyne (d) propanol

An organic compound \(\mathrm{X}\left(\mathrm{C}_{4} \mathrm{H}_{9} \mathrm{Cl}\right)\) on reaction with \(\mathrm{Na} /\) diethylether gives a hydrocarbon which on monochlorination gives only one chloro derivative then, \(\mathrm{X}\) is (a) t-butyl chloride (b) s-butyl chloride (c) iso-butyl chloride (d) \(\mathrm{n}\)-butyl chloride

Identify the final product (C) in the following sequence of reactions. \(\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{I} \stackrel{\text { Alc. } \mathrm{KOH}, \Delta}{\longrightarrow}(\mathrm{A}) \stackrel{\mathrm{Br}_{2}}{\longrightarrow}(\mathrm{B}) \stackrel{\mathrm{KCN}}{\longrightarrow}(\mathrm{C})\) (a) \(\mathrm{NCCH}_{2} \mathrm{CH}_{2} \mathrm{CN}\) (b) \(\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{Br}\) (c) \(\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CN}\) (d) \(\mathrm{BrCH}_{2} \mathrm{CH}_{2} \mathrm{CN}\)

Consider the following sequence of reactions \(\left(\mathrm{CH}_{3}\right)_{2} \mathrm{CHBr} \stackrel{\text { Ethanolic } \mathrm{KOH}}{\longrightarrow}(\mathrm{X}) \stackrel{\mathrm{Br}_{2}}{\longrightarrow}(\mathrm{Y})\) \(\frac{\mathrm{NaNH}_{2}}{\text { liq. } \mathrm{NH}_{3}}(\mathrm{Z})\) The end product \((Z)\) is (a) propane (b) propyne (c) propene (d) propan-2-al

Which one is the correct statement? (a) 2 -butene is Saytzeff's product (b) 1-butene is the Hofmann product (c) both (a) and (b) are correct (d) none is correct

The major product obtained in following addition reaction is \(\mathrm{H}_{2} \mathrm{C}=\mathrm{CH}-\mathrm{CH}_{2} \mathrm{Br} \stackrel{\mathrm{HBr}}{\longrightarrow} ?\) (a) \(\mathrm{BrCH}_{2} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{Br}\) (b) \(\mathrm{CH}_{2}=\mathrm{C}=\mathrm{CH}_{2}^{2}\) (c) \(\mathrm{CH}_{3}-\mathrm{CH}-\mathrm{CH}_{2} \mathrm{Br}\) (d) none of the above

The refluxing of the silver salt of the carboxylic acid in \(\mathrm{CCl}_{4}\) to form haloalkane or haloarene is called (a) Friedel-Crafts reaction (b) Wittig reaction (c) Hoffmann's bromamide reaction (d) Hunsdiecker reaction

A compound \(\mathrm{P}\left(\mathrm{C}_{3} \mathrm{H}_{6} \mathrm{Cl}_{2}\right)\) on reaction with an alkali either gives a compound \(\mathrm{Q}\left(\mathrm{C}_{3} \mathrm{H}_{6} \mathrm{O}\right)\) or \(\mathrm{R}\left(\mathrm{C}_{3} \mathrm{H}_{4}\right) .\) On oxidation, Q gives a compound \(\mathrm{C}_{3} \mathrm{H}_{6} \mathrm{O}_{2} . \mathrm{R}\), on reacting with dilute \(\mathrm{H}_{2} \mathrm{SO}_{4}\) containing \(\mathrm{Hg}^{2+}\) ion, gives a compound \(\mathrm{S}\left(\mathrm{C}_{3} \mathrm{H}_{6} \mathrm{O}\right)\), which reacts with bromine and alkali to give sodium salt of \(\mathrm{C}_{2} \mathrm{H}_{4} \mathrm{O}_{2}\). Then \(\mathrm{P}\) is (a) \(\mathrm{CH}_{2} \mathrm{ClCH}_{2} \mathrm{CH}_{2} \mathrm{Cl}\) (b) \(\mathrm{CH}_{3} \mathrm{CCl}_{2} \mathrm{CH}_{3}^{2}\) (c) \(\mathrm{CH}_{3} \mathrm{CHClCH}_{3} \mathrm{Cl}\) (d) \(\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CHCl}_{2}\)

Which of the following product is obtained when o-xylene is treated with \(\mathrm{Br}_{2}\) in the presence of iron?

A compound \(\mathrm{X}\left(\mathrm{C}_{\mathrm{s}} \mathrm{H}_{8} \mathrm{Br}_{2}\right)\) gives an aldehyde \(\mathrm{Y}\) upon hydrolysis. Oxidation of \(\mathrm{Y}\) gives a dibasic acid of which only one mono-nitro derivative can be obtained. Identify \(\mathrm{X}\).

Which of the following statements is/are correct? 1\. \(\mathrm{CH}_{3} \mathrm{CHCl} . \mathrm{CH}_{3}\) is a secondary alkyl halide. 2\. Acetylene is formed when \(\mathrm{CH}_{2}=\mathrm{CH}-\mathrm{Cl}\) is heated with water. 3\. Iodoform gives a precipitate with \(\mathrm{AgNO}_{3}\) solution on heating, whereas chloroform does not. 4\. Freon \(\left(\mathrm{CCl}_{2} \mathrm{~F}_{2}\right)\) is prepared by the action of \(\mathrm{CCl}_{4}\) and \(\mathrm{SbF}_{3}\) in the presence of \(\mathrm{SbCl}_{5}\) as a catalyst. (a) 1,2 and 3 (b) 2,3 and 4 (c) 1,3 and 4 (d) 3 and 4

The decreasing order of reactivity of I. m-nitrobromobenzene II. \(2,4,6\)-trinitrobromobenzene III. p-nitrobromobenzene IV. and 2,4 -dinitrobromobenzene towards \(\mathrm{OH}^{-}\)ions is (a) \(\mathrm{I}>\mathrm{II}>\mathrm{III}>\mathrm{IV}\) (b) \(\mathrm{II}>\mathrm{IV}>\mathrm{I}>\mathrm{III}\) (c) \(\mathrm{II}>\mathrm{IV}>\mathrm{III}>\mathrm{I}\) (d) \(\mathrm{IV}>\mathrm{II}>\mathrm{III}>\mathrm{I}\)

Arrange the following halides in the decreasing order of \(\mathrm{S}_{\mathrm{N}}^{1}\) reactivity. I. \(\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{Cl}\) II. \(\mathrm{CH}_{2}=\mathrm{CHCH}(\mathrm{Cl}) \mathrm{CH}_{3}\) III. \(\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CH}(\mathrm{Cl}) \mathrm{CH}_{3}\) (a) \(\mathrm{I}>\mathrm{II}>\mathrm{III}\) (b) \(\mathrm{II}>\mathrm{III}>\mathrm{I}\) (c) \(\mathrm{II}>\mathrm{I}>\mathrm{III}\) (d) III > II >I

Match List I (compound) with List II (use) and select the correct answer using the codes given below the lists: List I List II (Compound) (Use) I. acetylsalicylic A. insecticide II. DDT B. drug III. naphthalene C. moth repellent IV. carbon tetrachloride D. fire extinguisher E. refrigerant (a) I-E, II-A, III-C, IV-D (b) I-B, II-C, III-D, IV-A (c) I-E, II-C, III-D, IV-A (d) I-B, II-A, III-C, IV-D

Consider the following compounds: I. DDT II. gammexane III. carbon tetrachloride IV. chlorobenzene The correct sequence of these compounds in the increasing order of percentage of chlorine in them is (a) I, II, III, IV (b) IV, I, II, III (c) IV, II, I, III (d) III, I, II, IV

Consider the following haloalkanes: 1\. \(\mathrm{CH}_{3} \mathrm{~F}\) 2\. \(\mathrm{CH}_{3} \mathrm{Cl}\) 3\. \(\mathrm{CH}_{3} \mathrm{Br}\) 4\. \(\mathrm{CH}_{3} \mathrm{I}\) The increasing order of reactivity in nucleophilic substitution reaction is (a) \(4<3<2<1\) (b) \(1<3<2<4\) (c) \(1<2<3<4\) (d) \(1<2<4<3\)

Which of the following will give a positive carbylamine test? 1\. \(\mathrm{H}_{3} \mathrm{C}-\mathrm{NH}_{2}\) 2\. \(\mathrm{H}_{3} \mathrm{C}-\mathrm{NH}-\mathrm{CH}_{3}\) 3\. \(\left(\mathrm{CH}_{3}\right)_{3} \mathrm{~N}\) 4\. \(\mathrm{C}_{6} \mathrm{H}_{5}-\mathrm{NH}_{2}\) Select the correct answer using the codes given below. (a) 1 and 3 (b) 2 and 4 (c) 1 and 4 (d) 3 and 4

Identify the set of reagents/reaction conditions 'X' and ' \(\mathrm{Y}\) ' in the following set of transformations: CCCBr (a) \(\mathrm{X}=\) dilute aqueous \(\mathrm{NaOH}, 20^{\circ} \mathrm{C}\) \(\mathrm{Y}=\mathrm{HBr} /\) acetic acid, \(20^{\circ} \mathrm{C}\) (b) \(\mathrm{X}=\) concentrated alcoholic \(\mathrm{NaOH}, 80^{\circ} \mathrm{C}\) \(\mathrm{Y}=\mathrm{HBr} /\) acetic acid, \(20^{\circ} \mathrm{C}\) (c) \(\mathrm{X}=\) dilute aqueous \(\mathrm{NaOH}, 20^{\circ} \mathrm{C}\) \(\mathrm{Y}=\mathrm{Br}_{2} / \mathrm{CHCl}_{3}, 0^{\circ} \mathrm{C}\) (d) \(\mathrm{X}=\) concentrated alcoholic \(\mathrm{NaOH}, 80^{\circ} \mathrm{C}\) \(\mathrm{Y}=\mathrm{Br}_{2} / \mathrm{CHCl}_{3}, 0^{\circ} \mathrm{C}\)

Toluene when treated with \(\mathrm{Br}_{2}\) and \(\mathrm{Fe}\), gives \(\mathrm{p}\)-bromotoluene as the major product, because the methyl group 1\. is para-directing 2\. is m-directing 3\. activates the ring by hyperconjugation 4\. deactivates the ring of the above (a) 1,3 (b) \(1,2,3\) (c) 1,2 (d) none of these

Aryl halides are less reactive towards nucleophilic substitution reactions as compared to alkyl halides due to 1\. the formation of less stable carbonium ion 2\. resonance stabilization 3\. longer carbon-halogen bond 4\. the inductive effect 5\. sp \(^{2}\) hybridized carbon attached to halogen (a) \(1,2,3\) (b) \(2,4,5\) (c) 2,5 (d) 4,5

Arrange the following in the order of decreasing tendency towards \(\mathrm{S}_{\mathrm{N}}^{2}\) reaction 1\. \(\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{Cl}\) 2\. \(\mathrm{CH}_{3} \mathrm{CH}_{2}-\mathrm{CHCl}-\mathrm{CH}_{3}\) 3\. \(\left(\mathrm{CH}_{3}\right)_{2} \mathrm{CHCH}_{2} \mathrm{Cl}\) 4\. \(\left(\mathrm{CH}_{3}\right)_{3} \mathrm{C}-\mathrm{Cl}\) (a) \(1>3>2>4\) (b) \(4>4>3>1\) (c) \(2>1>3>4\) (d) \(1>2>4>3\)

Which of the following order represents the increasing order of reactivity towards \(\mathrm{Br}^{-}\)under \(\mathrm{S}_{\mathrm{N} 1}\) conditions? 1\. vinyl chloride 2\. methyl chloride 3\. ethyl chloride 4\. allyl chloride (a) \(4<3<2<1\) (b) \(1<2<3<4\) (c) \(2<1<3<4\) (d) \(2<1<4<3\)