Chapter 23

The IUPAC name of \(\mathrm{C}_{6} \mathrm{H}_{5} \mathrm{COCl}\) is (a) benzoyl chloride (b) benzene chloroketone (c) benzene carbonyl chloride (d) chlorophenyl ketone

In the reaction, \(\mathrm{CH}_{3} \mathrm{CHO}+\mathrm{HCN} \longrightarrow \mathrm{CH}_{3} \mathrm{CH}(\mathrm{OH}) \mathrm{CN}\) a chiral centre is produced. This product would be (a) racemic mixture (b) meso compound (c) dextrorotatory (d) laevorotatory

Optical activity is measured by (a) refractometer (b) tracer technique (c) spectrograph (d) polarimeter

The compound having only primary hydrogen atoms is (a) isobutene (b) 2,3 -dimethyl but-2-ene (c) cyclohexane (d) propyne

Which of the following shows geometrical isomerism? (a) but-1-ene (b) but-2-ene (c) 2,3 -dichlorobutane (d) ethene

The number of optically active isomers of tartaric acid is CC(O)C(=O)O \(\mathrm{CH}(\mathrm{OH}) \mathrm{COOH}\) (a) 2 (b) 3 (c) 4 (d) 1

The compound in which \(\mathrm{C}\) uses only its \(\mathrm{sp}^{3}\) hybrid orbitals for bond formation is (a) \(\mathrm{HCOOH}\) (b) \(\left(\mathrm{NH}_{2}\right)_{2} \mathrm{CO}\) (c) \(\left(\mathrm{CH}_{3}\right)_{3} \mathrm{COH}\) (d) \(\mathrm{CH}_{3} \mathrm{CHO}\)

Number of isomers which can be obtained theoretically from monochlorination of 2 -methylbutane are (a) 2 (b) 3 (c) 4 (d) 5

An organic molecule necessarily shows optical activity if it (a) is non-superimposable on its mirror image (b) is superimposable on its mirror image (c) contains asymmetric carbon atoms (d) is non-polar

How many structural isomers of \(\mathrm{C}_{4} \mathrm{H}_{10} \mathrm{O}\) that are ethers? (a) 1 (b) 2 (c) 3 (d) 4

Which of the following has zero dipole moment? (a) 1 -butene (b) cis-2-butene (c) trans-2-butene (d) 2 methyl-1-propene

The most stable conformation of ethylene glycol is (a) anti (b) gauche (c) fully eclipsed (d) partially eclipsed

The total number of isomers for \(\mathrm{C}_{4} \mathrm{H}_{8}\) are (a) 8 (b) 7 (c) 6 (d) 5

How many stereoisomers are there for tartaric acid? (a) 3 (b) 4 (c) 5 (d) 0

The number of enantiomers of the compound \(\mathrm{CH}_{3} \mathrm{CHBrCHBrCOOH}\) is (a) 1 (b) 2 (c) 3 (d) 4

Which of the following compounds will show metamerism? (a) \(\mathrm{CH}_{3}-\mathrm{O}-\mathrm{C}_{2} \mathrm{H}_{5}\) (b) \(\mathrm{CH}_{3}-\mathrm{O}-\mathrm{CH}_{3}\) (c) \(\mathrm{CH}_{3}-\mathrm{CO}-\mathrm{C}_{2} \mathrm{H}_{5}\) (d) \(\mathrm{C}_{2} \mathrm{H}_{5}-\mathrm{S}-\mathrm{C}_{2} \mathrm{H}_{5}\)

What will be the IUPAC name of given compound? CCC(C)CC(CC)CC (a) 2,5 -diethyl-4-methylhexane (b) \(3,3,6\)-trimethyloctane (c) \(2,5,6\)-trimethyloctane (d) 3,5 -dimethyl-6-ethylheptane

In the boat conformation of cyclohexane, the most destabilizing interaction is (a) eclipsing (b) flagpole-flagpole (c) 1,3 -diaxial (d) 1,3 -diequatorial

The most stable conformation of \(\mathrm{n}\)-butane is (a) eclipsed (b) gauche (c) anti-staggered (d) skew-boat

(+)-mandelic acid has a specific rotation of \(+158^{\circ}\). What would be the observed specific rotation of a mixture containing \(25 \%\) (-)-mandelic acid and \(75 \%\) (+)-mandelic acid? (a) \(+79^{\circ}\) (b) \(-118.5^{\circ}\) (c) \(-79^{\circ}\) (d) \(+118.5^{\circ}\)

Among the following, the most stable compound is (a) cis-1, 2-cyclohexanediol (b) trans-1, 2-cyclohexanediol (c) cis-1, 3-cyclohexenediol (d) trans- 1,3 -cyclohexanediol

The number of isomers possible for \(\mathrm{C}_{7} \mathrm{H}_{8} \mathrm{O}\) are (a) 3 (b) 4 (c) 5 (d) 6

The number of geometrical isomers of \(\mathrm{CH}_{3} \mathrm{CH}=\mathrm{CH}-\mathrm{CH}=\mathrm{CH}-\mathrm{CH}=\mathrm{CHCl} \mathrm{are}\) (a) 4 (b) 6 (c) 8 (d) 10

\(\mathrm{C}_{3} \mathrm{H}_{9} \mathrm{~N}\) cannot represent (a) quaternary salt (b) \(1^{\circ}\) amine (c) \(2^{\circ}\) amine (d) \(3^{\circ}\) amine

Which of the following is optically active? (a) butane (b) 2 -methylpentane (c) 4 -methylpentane (d) 3-methylheptane

The hybridization of carbon atoms in \(\mathrm{C}-\mathrm{C}\) single bond of \(\mathrm{HC} \equiv \mathrm{C}-\mathrm{CH}=\mathrm{CH}_{2}\) is (a) sp \(^{3}-\mathrm{sp}^{3}\) (b) \(\mathrm{sp}^{2}-\mathrm{sp}^{3}\) (c) \(\mathrm{sp}^{2}-\mathrm{sp}\) (d) \(\mathrm{sp}^{3}-\mathrm{sp}\)

Number of \(\pi\)-electrons in cyclobutadienyl anion \(\left(\mathrm{C}_{4} \mathrm{H}_{4}\right)^{2-}\) is (a) 2 (b) 4 (c) 6 (d) 8

The \(\mathrm{R}\) and \(\mathrm{S}\) enantiomers of an optically active compound differs in (a) their optical rotation of plane polarized light (b) their reactivity with a chiral reagents (c) their solubility in achiral reagents (d) their melting points

The number of primary amines of formula \(\mathrm{C}_{4} \mathrm{H}_{11} \mathrm{~N}\) are (a) 2 (b) 3 (c) 4 (d) 5

But-2-ene exhibits cis-transisomerism due to (a) rotation around \(\mathrm{C}_{3}-\mathrm{C}_{4}\) sigma bond (b) rotation around \(\mathrm{C}_{1}-\mathrm{C}_{2}\) bond (c) restricted rotation around \(\mathrm{C}=\mathrm{C}\) bond (d) rotation around \(\mathrm{C}_{2}-\mathrm{C}_{3}\) double bond

The C-C bond length of the following molecules are in the order (a) \(\mathrm{C}_{2} \mathrm{H}_{6}>\mathrm{C}_{2} \mathrm{H}_{4}>\mathrm{C}_{6} \mathrm{H}_{6}>\mathrm{C}_{2} \mathrm{H}_{2}\) (b) \(\mathrm{C}_{2} \mathrm{H}_{2}<\mathrm{C}_{2} \mathrm{H}_{4}<\mathrm{C}_{6} \mathrm{H}_{6}<\mathrm{C}_{2} \mathrm{H}_{6}\) (c) \(\mathrm{C}_{2} \mathrm{H}_{6}>\mathrm{C}_{2} \mathrm{H}_{2}>\mathrm{C}_{6} \mathrm{H}_{6}>\mathrm{C}_{2} \mathrm{H}_{4}\) (d) \(\mathrm{C}_{2} \mathrm{H}_{4}>\mathrm{C}_{2} \mathrm{H}_{6}>\mathrm{C}_{2} \mathrm{H}_{2}>\mathrm{C}_{6} \mathrm{H}_{6}\)

An isomer of ethanol is (a) methanol (b) diethyl ether (c) acetone (d) dimethyl ether

An organic molecule necessarily shows optical activity if it (a) contains asymmetric carbon atoms (b) is non-planar (c) is non-superimposable on its mirror image (d) is superimposable on its mirror image

The maximum number of carbon atoms arranged linearly in the molecule, \(\mathrm{CH}_{3}-\mathrm{C} \equiv \mathrm{C}-\mathrm{CH}=\mathrm{CH}_{2}\) are (a) 3 (b) 4 (c) 5 (d) 6

The IUPAC name of cinnamic acid is (a) phenylpropanoic acid (b) 3-phenylprop-2-enoic acid (c) 3-phenylpropanoic acid (d) benzene-1, 4 -dicarboxylic acid

The IUPAC name of the compound \(\mathrm{CH}_{3}-\mathrm{C}\left(\mathrm{CH}_{3}\right)_{2}-\mathrm{CH}=\mathrm{C}\left(\mathrm{CH}_{3}\right)_{2}\) is (a) \(1,1,3,3\)-tetramethyl-but- 1 -ene (b) \(1,3,3\)-trimethyl-pent-2-ene (c) \(2,2,4\)-trimethylbut-4-ene (d) \(2,4,4\)-trimethylpent- 2 -ene

One recently discovered allotrope of carbon \(\left(\mathrm{C}_{60}\right)\) is commonly known as (a) fluorine (b) fluorene (c) freon (d) fullerene

The optically active tartaric acid is named as \(\mathrm{D}-(+)\) tartaric acid because it has a positive (a) optical rotation and is derived from D-glucose (b) \(\mathrm{pH}\) in an organic solvent (c) optical rotation and is derived from D-(+)glyceraldehyde (d) optical rotation only when substituted by deuterium

Keto \(-\) enol tautomerism is observed in : (a) \(\mathrm{C}_{6} \mathrm{H}_{5} \mathrm{CHO}\) (b) \(\mathrm{C}_{6} \mathrm{H}_{5} \mathrm{OCH}_{3}\) (c) \(\mathrm{C}_{6} \mathrm{H}_{3} \mathrm{COCH}_{2} \mathrm{COOH}\) (d) \(\mathrm{C}_{6} \mathrm{H}_{5} \mathrm{COC}_{6} \mathrm{H}_{5}\)

Maximum enol content is observed in (a) \(\mathrm{CH}_{3} \mathrm{COCH}_{2} \mathrm{COOC}_{2} \mathrm{H}_{5}\) (b) O=C1C=CC=CC1 (c) \(\mathrm{CH}_{3} \mathrm{COCH}_{2} \mathrm{COCH}_{3}\) (d) \(\mathrm{CH}_{3} \mathrm{COCH}_{3}\)

Assign the IUPAC name to \(\left[\left(\mathrm{CH}_{3}\right)_{2} \mathrm{CH}\right]_{3} \mathrm{COH}\). (a) 3 -( 2 -methylethyl)-3(1-methylethyl) pentan-2-ol (b) tris-(1-methylpropyl)methanol (c) 2, 4-dimethyl-3 (1-methylethyl) pentan- 2 -ol (d) 3 -(1-methylethyl) \(-2,4\)-dimethylpentan-3-ol

2 -methylpenta- 2,3 -diene is achiral as it has (a) a centre of symmetry (b) a plane of symmetry (c) a \(\mathrm{C}_{2}\) axis of symmetry (d) both centre and a plane of symmetry

Which class of compound can exhibit geometrical isomerism (a) \(\mathrm{CH}_{3} \mathrm{CH}=\mathrm{CHCH}_{3}\) (b) \(\mathrm{C}_{6} \mathrm{H}_{5} \mathrm{CH}=\mathrm{NOH}\) (c) O=C(O)C=CC(=O)O (d) All of these

The bond between carbon atom (1) and carbon atom (2) in compound \(\mathrm{N} \equiv \mathrm{C}-\mathrm{CH}=\mathrm{CH}_{2}\) involves the hybridization (a) \(\mathrm{sp}^{2}\) and \(\mathrm{sp}^{2}\) (b) \(\mathrm{sp}^{3}\) and sp (c) sp and sp \(^{2}\) (d) sp and sp

Which IUPAC name is correct for the given compound? CC(C)=CCCC(C)=CC=O (a) 3,7 -dimethyloct- 2,6 -dienal (b) 2,6 -dimethyloct- 2,6 -dienal-8 (c) 7 -formyl-2, 6-dimethylhept \(-2,6\)-diene (d) 7 -aldo- 2,6 -dimethylhept- 2,6 -diene

The total number of optically active isomers for \(\mathrm{CH}_{2} \mathrm{OH}(\mathrm{CHOH})_{3} \mathrm{CHO}\) are (a) 16 (b) 8 (c) 4 (d) 2

Total number of isomers and optically active compounds in the isomers of \(\mathrm{C}_{3} \mathrm{H}_{5} \mathrm{Br}\) are (a) 6,4 (b) 5,3 (c) 3,5 (d) 8,3

On monochlorination of n-pentane, the number of isomers formed is are (a) 4 (b) 3 (c) 2 (d) 1

The compound (1) and (2) can be regarded as CC(C)C(O)C(C)O CC(O)C(C)O (1) (2) (a) enantiomers (b) diastereomers (c) mesomers (d) geometrical isomer

Assign the IUPAC name for the following compound. Clc1ccc(N=Nc2cccc(Cl)c2)cc1 (a) 3,4 -dichloroazobenzene (b) (4-chlorophenyl) (3-chlorophenyl) diazene (c) 3,4 -bis(chlorophenyl) diazene (d) (3-chlorophenyl) (4-chlorophenyl) diazene