Chapter 3

When the trans-2-pentene is treated with \(\mathrm{Br}_{2}\) in the presence of \(\mathrm{CCl}_{4}\), then the number of stereoisomers formed is (a) 1 (b) 2 (c) 3 (d) 4

Major product of reaction between cycloheptyne and \(\mathrm{H}_{2} \mathrm{O}, \mathrm{H}_{2} \mathrm{SO}_{4} / \mathrm{HgSO}_{4}\) is

An optically active organic compound has the molecular formula \(\mathrm{C}_{7} \mathrm{H}_{10}\) (A). On reaction with \(\mathrm{H}_{2}+\mathrm{Pt}\) it forms an optically inactive compound (B). Then, compound (A) will be

Which of the following is most reactive towards aqueous \(\mathrm{HBr}\) ? (a) 1-Phenyl-2-propanol (b) 1-Phenyl-1-propanol (c) 3-Phenyl-1-propanol (d) 2-Phenyl-1-propanol

1-Penten-4-yne reacts with bromine at \(-80^{\circ} \mathrm{C}\) to produce (a) \(4,4,5,5\) -Tetrabromopentene (b) 1,2 -Dibromo- 1,4 -pentadiene (c) \(1,1,2,2,4,5\) -hexabromopentane (d) 4,5 -dibromopentyne

Which of the following reagents cannot be used to locate the position of triple bond in \(\mathrm{CH}_{3}-\mathrm{C}=\mathrm{C}-\mathrm{CH}_{3} ?\) (a) \(\mathrm{Br}_{2}\) (b) \(\mathrm{O}_{3}\) (c) \(\mathrm{Cu}_{2}^{2+}\) (d) \(\mathrm{KMnO}_{4}\)

Methanoic acid is heated with conc. \(\mathrm{H}_{2} \mathrm{SO}_{4}\) to form (a) \(\mathrm{CO}\) (b) \(\mathrm{CO}_{2}\) (c) \(\mathrm{CH}_{4}\) (d) \((\mathrm{COOH})_{2}\)

When ethane-1,2-dioic acid is heated with conc. \(\mathrm{H}_{2} \mathrm{SO}_{4^{\prime}}\) it gives (a) \(\mathrm{CO}+\mathrm{HCOOH}\) (b) \(\mathrm{CO}_{2}+\mathrm{HCOOH}\) (c) \(\mathrm{CO}+\mathrm{CO}_{2}+\mathrm{HCOOH}\) (d) \(\mathrm{CO}+\mathrm{CO}_{2}+\mathrm{H}_{2} \mathrm{O}\)

When sodium fumrate is heated with soda lime, we get (a) \(\mathrm{CH}_{4}\) (b) Ethyne (c) Sodium oxalate (d) No action

Sodium formate is heated at \(360^{\circ} \mathrm{C}\) to gives (a) \(\mathrm{CO}\) (b) \(\mathrm{CO}_{2}\) (c) Sodium oxalate (d) No action

Product of the reaction \(\mathrm{CH}_{3}-\mathrm{CH}=\mathrm{CH}-\mathrm{CH}_{3} \frac{\mathrm{O}_{3} / \mathrm{CH}_{2} \mathrm{C}_{2}}{-78^{\circ} \mathrm{C}} \longrightarrow\) will be

In the given reaction, \(\mathrm{CH}_{3}-\mathrm{CH}_{2}-\mathrm{C} \equiv \mathrm{C}-\mathrm{H} \frac{\left(\text { i) } \mathrm{BH}_{3}\right.}{\text { (ii) } \mathrm{H}_{2} \mathrm{O}_{2} / \mathrm{OH}^{-}}[\mathrm{X}],[\mathrm{X}]\) will be (a) Butanal (b) Butanone (c) 2 -butanol (d) 1 -butanol

\(\mathrm{CH}_{3}-\mathrm{CH}_{2}-\mathrm{CH}_{2}-\mathrm{CH}_{3} \frac{\mathrm{CrO}_{3} / \mathrm{Al}_{2} \mathrm{O}_{3}}{600^{\circ} \mathrm{C}}[\mathrm{P}] ;\) Product is (a) Mixture of 1-butene and 2 -butene (b) Cyclobutene (c) 1,3 -cyclobutadiene (d) None of these

In the given reaction, \(\mathrm{C}_{6} \mathrm{H}_{5}-\mathrm{C} \equiv \mathrm{C}-\mathrm{CH}_{3} \stackrel{\mathrm{Na} / \mathrm{NH}_{3}(\mathrm{I})}{\longrightarrow}[\mathrm{X}],[\mathrm{X}]\) will be (a) 1-phenyl propane (b) 1-phenyl propene (c) trans-1-phenyl propene (d) cis-1-phenyl propene

In the presence of peroxide, HCl and HI do not give Anti-Markovnikov's additon to alkenes because (a) All the steps are endothermic in both the cases (b) One is oxidising 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

In the given reaction, \(\mathrm{CH}_{3}-\mathrm{CH}_{2}-\mathrm{C} \equiv \mathrm{C}-\mathrm{CH}_{3}+\mathrm{HOH} \stackrel{\mathrm{HOH} / \mathrm{H} / \mathrm{Hg}_{8}^{+}}{\longrightarrow}[\mathrm{X}],[\mathrm{X}]\) will be (a) 2-pentanone (b) 3 -pentanone (c) Pentanol (d) Mixture of 2 -pentanone and 3 -pentanone

Hydrogenolysis is a process of (a) Addition of \(\mathrm{H}_{2}\) across \(\mathrm{C}-\mathrm{C}\) multiple bond (b) Elimination of \(\mathrm{H}_{2}\) in \(\mathrm{CH}-\mathrm{CH}\) bonds (c) Cleavage of a single bond by \(\mathrm{H}_{2}\) (d) Cleavage of \(C-C\) multiple bonds by \(H_{2}\)

. In the reaction with Tollen's reagent actylene shows (a) Oxidising property (b) Reducing property (c) Basic property (d) Acidic property

Arrange the following halogenating agents in order of decreasing selectivity in free radical reactions (i) NBS (ii) \(\mathrm{NCS}\) (iii) \(\mathrm{Cl}_{2}\) (iv) \(\mathrm{F}_{2}\) (a) \(\mathrm{iv}>\mathrm{iii}>\mathrm{ii}>\mathrm{i}\) (b) \(\mathrm{i}>\mathrm{ii}>\mathrm{iii}>\mathrm{iv}\) (c) \(\mathrm{ii}>\mathrm{i}>\mathrm{iii}>\mathrm{iv}\) (d) \(\mathrm{i}>\mathrm{ii}>\mathrm{iv}>\mathrm{iii}\)

\(8 \mathrm{~mL}\) of a gaseous hydrocarbon needs \(40 \mathrm{~mL}\) of oxygen for its complete combustion. The hydrocarbon is (a) \(\mathrm{CH}_{4}\) (b) \(\mathrm{C}_{3} \mathrm{H}_{4}\) (c) \(\mathrm{C}_{3} \mathrm{H}_{8}\) (d) \(\mathrm{C}_{3} \mathrm{H}_{6}\)

The lowest boiling point is expected for (a) Isooctane (b) \(\mathrm{n}\) -octane (c) \(\quad 2,2,3\), trimethyl butane (d) \(\mathrm{n}\) -heptane

The major product formed on hydroboration oxidation of 1-methylcyclopentene is

Compound (A) on bromination gives (B), which gives (C) with alcoholic KOH. (C) decolouries \(1 \%\) alkaline \(\mathrm{KMnO}_{4}\) solution and on ozonolysis, it gives two molecules of smallest carbonyl compound. Compound (A) will be (a) \(\mathrm{C}_{2} \mathrm{H}_{2}\) (b) \(\mathrm{C}_{2} \mathrm{H}_{4}\) (c) \(\mathrm{C}_{2} \mathrm{H}_{6}\) (d) \(\mathrm{C}_{2} \mathrm{H}_{5} \mathrm{Cl}\)

Acetic acid, when reacts with excess of HI in the presence of red phosphorus gives (a) Ethanol (b) Ethane (c) Acetaldehyde (d) Acetone

\(\mathrm{CH}_{2}=\mathrm{CH}-\mathrm{C} \equiv \mathrm{CH}\) on reaction with 1 mole of DBr gives (a) \(\mathrm{CH}_{2}=\mathrm{CH}-\mathrm{CBr}=\mathrm{CHD}\) (b) \(\mathrm{CH}_{2}(\mathrm{Br})-\mathrm{CHDC}=\mathrm{CH}\) (c) \(\mathrm{DCH}_{2}-\mathrm{CHBrC}=\mathrm{CH}\) (d) \(\mathrm{CH}_{2}=\mathrm{CH}-\mathrm{CD}=\mathrm{CHBr}\)

Sodium adipate, on electrolysis gives (a) Cyclobutane (b) Cyclopropane (c) But-2-ene (d) But-2-yne

During the preparation of ethane by Kolb's electrolytic method using inert electrode the pH of the electrolyte (a) Decreases progressively as the reaction proceeds (b) Increases progressively as the reaction proceeds (c) Remains constant throughout the reaction (d) May decrease if concentration of the electrolytes is not very high

The reaction of propene with HBr in the presence of ROOR (peroxide) proceeds through which of the following most stable intermediates? (a) \(\mathrm{CH}_{3}-\dot{\mathrm{CH}}-\mathrm{CH}_{3}\) (b) \(\mathrm{CH}_{3}-\mathrm{CH}-\mathrm{CH}_{2} \mathrm{Br}\) (c) (d) \(\mathrm{CH}_{3}-\mathrm{CH}_{2}-\mathrm{CH}_{2}\)

\(2 \mathrm{C}_{2} \mathrm{H}_{5} \mathrm{Cl}+\mathrm{Zn} \longrightarrow \mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{CH}_{3}+\mathrm{ZnCl}_{2}\). The reaction is known as (a) Frankland reaction (b) Wurtz reaction (c) Fittig reaction (d) Wurtz-Fittig reaction

When isobutane is chlorinated in the presence of diffused sunlight, then the product formed is (a) tertiary butyl chloride in major amount (b) isobutyl chloride in major amount (c) both \(50 \%\) each (d) n-butyl chloride, isobutyl chloride and sec-butyl chloride are formed

When isobutane is brominated in the presence of diffused sunlight then the product formed is (a) exclusively tertiary butyl bromide (b) exclusively isobutyl bromide (c) exclusively \(\mathrm{n}\) -butyl bromide (d) s-butyl bromide

Which of the following gives glyoxal as one of the product on ozonolysis?

When cyclohexadiene (A) reacts with \(\mathrm{Br}_{2^{\prime}}\) a mixture of cis- and trans-1, 2 -addition products is formed (in addition to other products). However, when cyclohexene (B) reacts with \(\mathrm{Br}_{2}\) under identical conditions, only trans product is observed. What is the best explanation for the observed difference in stereochemistry of the addition? (a) The cis and trans products are the result of aromaticity in the cyclic TS for reaction of A. In \(B\) there are only four electrons in TS, and cyclic TS is destabilised. (b) Reaction of A proceeds through an intermediate that has an \(\mathrm{sp}^{3}\) -hybridised carbocation, while the analogous intermediate in reaction of B has sp-hybridised carbocation. (c) Both reactions occur through bromonium ions, but because of planarity enforced by neighbouring double bond, cis addition is not sterically hindered in A. (d) B reacts through a bromonium ion intermediate, while A does through an allyl cation.

The reaction of propane with nitric acid in vapour phase gives (a) 1-nitropropane (b) 2-nitropropane (c) Nitromethane (d) Nitroethane

Iodination of methane can be carried out in the presence of (a) HI (b) \(\mathrm{HIO}_{3}\) (c) \(\mathrm{HNO}_{3}\) (d) \(\mathrm{NaOH}\)

Cracking of alkanes involves (a) Homolytic fission (b) Free radical (c) Heterolytic fission (d) Carbocation

\(\mathrm{Ph}-\mathrm{CH}=\mathrm{CH}_{2}+\mathrm{BrCCl}_{3} \stackrel{\text { peroxide }}{\longrightarrow}\) Product is

In which compound addition reaction will take place according to anti- Morkonikov's rule? (i) \(\mathrm{CH}_{2}=\mathrm{CH}-\mathrm{NO}_{2}\) (ii) \(\mathrm{CH}_{2}=\mathrm{CH}-\mathrm{CHO}\) (iii) \(\mathrm{CH}_{2}=\mathrm{CH}-\mathrm{CN}\) (iv) \(\mathrm{CH}_{3}-\mathrm{CH}=\mathrm{CH}_{2}\) Select the correct anwer (a) \(\mathrm{i}\), ii and iii (b) \(\mathrm{i}\), ii and iv (c) \(\mathrm{i}\) and ii (d) \(\mathrm{i}\) and iii

For electrophilic addition with HCl, which pair is correctly matched? (i) \(\mathrm{CH}_{3}-\mathrm{CH}=\mathrm{CH}_{2^{\prime}}\) alkyl carbocation (ii) \(\mathrm{CH}_{3}-\mathrm{CH} \equiv \mathrm{CH}\), vinyl carbocation (iii) \(\mathrm{CH}_{2}=\mathrm{CH}-\mathrm{CH}=\mathrm{CH}_{2^{\prime}}\), allyl carbocation Select the correct answer (a) \(\mathrm{i}\), iii and iv (b) ii, iii and iv (c) \(\mathrm{i}\), ii and iii (d) i, ii and iv

Select true statement(s) (a) Instead of radical substitution, cyclopropane undergoes electrophilic addition reactions in sun light. (b) In general, bromination is more selective than chlorination. (c) The 2, 4, 6-tri-tert,butylphenoxy radical is resistant to dimerisation. (d) The radical-catalysed chlorination, \(\mathrm{ArCH}_{3} \rightarrow \mathrm{ArCH}_{2} \mathrm{Cl}\), occurs faster when \(\mathrm{Ar}=\) phenyl than when \(\mathrm{Ar}=\mathrm{p}\) -nitrophenyl.

Consider the following statements (i) Alkene is more reactive than alkyne for electrophilic addition reaction. (ii) Alkyne gives nucleophilic as well as electrophilic addition reaction. (iii) Alkyne is more reactive than alkene for nucleophilic addition reaction. (iv) For electrophilic addition reaction, RI of alkyne is alkyl carbocation. Of these, the correct statements are (a) Only (b) \(\mathrm{i}\) and \(\mathrm{ii}\) (c) i, ii and iv (d) \(\mathrm{i}, \mathrm{ii}\) and \(\mathrm{iii}\)

Consider the following statements (i) Conjugated diene gives direct as well as conjugate addition. (ii) Conjugated diene gives only direct addition. (iii) Conjugated diene gives only conjugate addition. (iv) Thermodynamically controlled product is obtained by less stable reaction intermediate. Of these, the correct statements are (a) Only i (b) i and iv (c) ii and iii (d) Only iii

Consider the following statements (i) Conjugated diene gives i, 2 and i, 4 adduct. (ii) Conjugated diene gives kinetically and thermodynamically controlled product. (iii) Formation of kinetically controlled product takes place by formation of stable RI. (iv) Formation of thermodynamically controlled product takes place by the formation of stable RI. Of these, the correct statements are (a) i, ii and iii (b) i, ii and iv (c) Only (d) Only iv

Which among the following reagents give syn addition with alkenes? (i) \(\mathrm{Br}_{2}\) (ii) dil. \(\mathrm{KMnO}_{4} / \mathrm{OH}^{-}\) (iii) \(\mathrm{OsO}_{4} / \mathrm{NaSO}_{3} \mathrm{H} / \mathrm{HOH}\) (iv) \(\mathrm{H}_{2} / \mathrm{Ni} / \Delta\) Select the correct answer (a) Only (b) ii and iii (c) ii, iii and iv (d) Only iv

Alkyne can be converted into vic dicarbonyl compound by (a) \(\mathrm{SeO}_{2}\) (b) Baeyer's reagent (c) \(\mathrm{KMnO}_{4} / \mathrm{H}^{\oplus}\) (d) \(\mathrm{K}_{2} \mathrm{Cr}_{2} \mathrm{O}_{7}\)

The reagent(s) of choice for conversion of propene to methylcyclopropane is /are (a) \(\mathrm{CH}_{2} \mathrm{~N}_{2} /\) ether (b) \(\mathrm{CH}_{2} \mathrm{I}_{2}\) (c) \(\mathrm{CH}_{2} \mathrm{I}_{2} / \mathrm{Zn}\) (d) \(\mathrm{CH}_{3} \mathrm{I} / \mathrm{NaOH}\)

Nitrobenzene can be reduced to aniline by (i) \(\mathrm{H}_{2} / \mathrm{Ni}\) (ii) \(\mathrm{Sn} / \mathrm{HCl}\) (iii) \(\mathrm{Zn} / \mathrm{NaOH}\) (iv) LiAlH \(_{4}\) (a) \(\mathrm{i}\), ii and iii (b) \(\mathrm{i}\) and \(\mathrm{ii}\) (c) \(\mathrm{i}, \mathrm{ii}\) and \(\mathrm{iv}\) (d) only ii

Nitrobenzene can be reduced to aniline by (i) \(\mathrm{H}_{2} / \mathrm{Ni}\) (ii) \(\mathrm{Sn} / \mathrm{HCl}\) (iii) \(\mathrm{Zn} / \mathrm{NaOH}\) (iv) LiAlH \(_{4}\) (a) i, ii and iii (b) \(\mathrm{i}\) and \(\mathrm{ii}\) (c) i, ii and iv (d) only ii

2-methylpropanol- 2 can be obtained by the acid-catalysed hydration of (a) \(\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CH}=\mathrm{CH}_{2}\) (b) \(\mathrm{CH}_{3} \mathrm{CH}=\mathrm{CHCH}_{3}\) (c) \(\left(\mathrm{CH}_{3}\right)_{2} \mathrm{C}=\mathrm{CHCH}_{3}\) (d) either of the three

Predict the nature of \(\mathrm{P}\) in the following reaction: \(\mathrm{CH}_{3} \mathrm{C} \equiv \mathrm{CCH}_{3} \frac{\mathrm{NaNH}_{2} / \text { ineer solvent }}{\text { heat }} \mathrm{P}\) (a) \(\mathrm{CH}_{2}=\mathrm{CHCH}=\mathrm{CH}_{2}\) (b) \(\mathrm{CH}_{2}=\mathrm{C}=\mathrm{CH}-\mathrm{CH}_{3}\) (c) \(\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{C}=\mathrm{CH}\) (d) No reaction