Chapter 26

Wurtz reaction involves the reduction of alkyl halide with (a) HI (b) \(\mathrm{Zn} / \mathrm{HCl}\) (c) 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 reaction of the formation of bromobenzyl chloride with \(\mathrm{NaCN}\) in ethanol leads to (a) 4-bromo-2-cyanobenzyl chloride (b) 4 -cyanobenzyl cyanide (c) 4-cyanobenzyl chloride (d) 4-bromobenzyl cyanide

\(\mathrm{CH}_{3}-\mathrm{CH}_{2}-\mathrm{CH}_{2}-\mathrm{Cl} \stackrel{\text { alc. } \mathrm{KOH}}{\longrightarrow}(\mathrm{X}) \stackrel{\mathrm{HBr}}{\longrightarrow}(\mathrm{Y}) \stackrel{\mathrm{Na} \text { /ether }}{\longrightarrow}(\mathrm{Z})\) 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 ben8 zene, \(\mathrm{C}_{6} \mathrm{H}_{5}-\mathrm{CH}_{2} \mathrm{Br} ?\) (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

The following transformation proceed through O=[N+]([O-])c1ccc(Cl)c([N+](=O)[O-])c1 O=[N+]([O-])c1ccc([N+](=O)[O-])c([N+](=O)[O-])c1 (a) benzyne intermediate (b) oxirane (c) electrophillic addition (d) activated nucleophillic substitution

Chlorination of toluene in the presence of light and heat followed by treatment with aqueous \(\mathrm{NaOH}\) 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) n-isobutylaniline (b) \(\beta\)-phenylethylamine (c) aniline (d) benzylamine

Identify \(Z\) in the following series: \(\mathrm{C}_{2} \mathrm{H}_{5} \mathrm{I} \stackrel{\mathrm{Alc} . \mathrm{KOH}}{\longrightarrow} \mathrm{X} \stackrel{\mathrm{Br}_{2}}{\longrightarrow \mathrm{Y}} \stackrel{\mathrm{KCN}}{\longrightarrow} \mathrm{Z}\) (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) \(\mathrm{CCl}_{4}>\mathrm{CHCl}_{3}>\mathrm{H}_{2} \mathrm{O}>\mathrm{CH}_{2} \mathrm{Cl}_{2}>\mathrm{CH}_{3} \mathrm{Cl}\)

Which of the following is an example of \(\mathrm{S}_{\mathrm{N}^{2}}\) reaction? (a) \(\mathrm{CH}_{3} \mathrm{Br}+\mathrm{OH}^{-} \longrightarrow \mathrm{CH}_{3} \mathrm{OH}+\mathrm{Br}\) (b) CC(Br)CC(CO)CBr (c) \(\mathrm{CH}_{3}-\mathrm{CH}_{2}-\mathrm{OH} \underset{2}{\mathrm{Heat}} \mathrm{H}_{2} \mathrm{O}+\mathrm{H}_{2} \mathrm{C}=\mathrm{CH}_{2}\) (d)

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

The pesticide DDT slowly changes to (a) p, p-dichlorodiphenyldichloroethene (b) p, p'-dichlorodiphenyldichloroethane (c) p, p'-dichlorodiphenylethene (d) \(\mathrm{CCl}_{3}-\mathrm{CHO}\) and chlorobenzene

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

\(\left(\mathrm{CH}_{3}\right)_{3} \mathrm{C}-\mathrm{Cl} \stackrel{\text { Acl. } \mathrm{KOH}}{\Delta} \rightarrow \mathrm{A} \frac{\mathrm{SO}_{2} \mathrm{Cl}_{2}}{475 \mathrm{~K}}-\mathrm{B}\) The compound \(\mathrm{B}\) 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) \(\mathrm{ClCH}_{2} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{CH}_{3}\) (d) \(\mathrm{CH}_{3} \mathrm{C}(\mathrm{Cl})\left(\mathrm{CH}_{3}\right) \mathrm{CH}_{2} \mathrm{CH}_{3}\)

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) \(\mathrm{C}_{6} \mathrm{H}_{3} \mathrm{CO}_{2} \mathrm{CH}_{3}\)

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) \(\mathrm{C}_{2} \mathrm{H}_{3} \mathrm{OH}\)

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

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

Which one of the following compounds undergoes substitution at a slower rate than benzene and yet yields predominantly ortho and para products? (a) phenol (b) chlorobenzene (c) nitrobenzene (d) benzene sulphonic acid

Reaction of ethyl benzene with bromine in presence of \(\mathrm{FeBr}_{3}\) gives (a) 2-bromoethyl benzene (b) 2 -bromoethyl benzene (c) 3-bromoethyl benzene (d) 4 -bromoethyl benzene

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

Propyl benzene reacts with bromine in presence of light or heat to give (a) CC(Br)Cc1ccccc1 (b) CCC(Br)c1ccccc1 (c) CCCc1ccccc1Br (d) BrCCCc1ccccc1

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 \(\left(\mathrm{CH}_{3}\right)_{2} \mathrm{CHBr} \stackrel{\text { Ethanolic } \mathrm{KOH}}{\longrightarrow}(\mathrm{X}) \stackrel{\mathrm{Br}_{2}}{\longrightarrow}(\mathrm{Y})\) \(\frac{\mathrm{NaNH}_{2}}{\mathrm{liq} \cdot \mathrm{NH}_{3}}(\mathrm{Z})\) 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

Replacement of \(\mathrm{Cl}\) of chlorobenzene to give phenol requires drastic conditions, but chlorine of 2,4 dinitrochlorobenzene is readily replaced because (a) \(-\mathrm{NO}_{2}\) makes the ring electron rich at ortho and para positions (b) \(-\mathrm{NO}_{2}\) withdraws electrons at meta position (c) \(-\mathrm{NO}_{2}\) donates electrons at meta position (d) \(-\mathrm{NO}_{2}\) withdraws electrons at ortho and para positions

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) \(\mathrm{CH}_{3} \mathrm{CCl}_{2} \mathrm{CH}_{3}\) (c) \(\mathrm{CH}_{3} \mathrm{CHClCH}_{2} \mathrm{Cl}\) (d) \(\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CHCl}_{2}\)

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

Which of the following pair is correctly matched? List I List II (Reaction) \(\quad\) (Product) I. \(\mathrm{RX}+\mathrm{AgCN} \quad \mathrm{RNC}\) II. RX + KCN \(\quad\) RCN III. \(\mathrm{RX}+\mathrm{KNO}_{2} \mathrm{R}-\mathrm{N} \leqslant_{\mathrm{O}}^{\nearrow \mathrm{O}}\) IV. \(\mathrm{RX}+\mathrm{AgNO}_{2} \quad \mathrm{R}-\mathrm{O}-\mathrm{N}=\mathrm{O}\) Select the correct answer using the codes given bels (a) I and II (b) III and IV (c) I only (d) I, II, III and IV

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) 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) \(\mathrm{III}>\mathrm{II}>\mathrm{I}\)

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) \(\mathrm{I}-\mathrm{B}, \mathrm{II}-\mathrm{C}, \mathrm{III}-\mathrm{D}, \mathrm{IV}-\mathrm{A}\) (c) \(\mathrm{I}-\mathrm{E}, \mathrm{II}-\mathrm{C}, \mathrm{III}-\mathrm{D}, \mathrm{IV}-\mathrm{A}\) (d) \(\mathrm{I}-\mathrm{B}, \mathrm{II}-\mathrm{A}, \mathrm{III}-\mathrm{C}, \mathrm{IV}-\mathrm{D}\)

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 \(\mathrm{NaOH}, 20^{\circ} \mathrm{C}\) \(\mathrm{Y}=\) 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