CBSE Questions for Class 12 Engineering Chemistry Haloalkanes And Haloarenes Quiz 7 - MCQExams.com

In $$S_{N}1$$, the first step involves the formation of:
  • free radical
  • carbanion
  • carbocation
  • final product
The product $$(D)$$ of the reaction will be:
$$C{ H }_{ 3 }Cl\xrightarrow { \ KCN\ } \left( A \right) \xrightarrow { \ { H }_{ 3 }{ O }^{ + }\  } \left( B \right) \xrightarrow { \ N{ H }_{ 3 }\  } \left( C \right) \xrightarrow { \Delta \  } \left( D \right) $$
  • $$C{ H }_{ 3 }C{ H }_{ 2 }N{ H }_{ 2 }$$
  • $$C{ H }_{ 3 }CN$$
  • $$HCON{ H }_{ 2 }$$
  • $$C{ H }_{ 3 }CON{ H }_{ 2 }$$
The most reactive towards $$S_{ N }{ 1 }$$ is:
  • $$PhC{ H }_{ 2 }Cl$$
  • $$PhCl$$
  • $$PhCH(Cl)C{ H }_{ 3 }  $$
  • $$p-N{ O }_{ 2 }PhC{ H }_{ 2 }Cl$$
Most stable carbocation formed from $${ \left( C{ H }_{ 3 } \right)  }_{ 3 }C-Br,   { \left( { C }_{ 6 }{ H }_{ 5 } \right)  }_{ 3 }CBr,   { \left( { C }_{ 6 }{ H }_{ 5 } \right)  }_{ 2 }CHBr$$ and $${ C }_{ 6 }{ H }_{ 5 }C{ H }_{ 2 }Br$$ would be:
  • $${ C }_{ 6 }{ H }_{ 5 }\overset { \oplus }{ C } { H }_{ 2 }$$
  • $${ \left( C{ H }_{ 3 } \right) }_{ 3 }\overset { \oplus }{ C } $$
  • $${ \left( { C }_{ 6 }{ H }_{ 5 } \right) }_{ 3 }\overset { \oplus }{ C } $$
  • $${ \left( { C }_{ 6 }{ H }_{ 5 } \right) }_{ 2 }\overset { \oplus }{ C } H$$
Bond pair of electrons in $$C-X$$ bond is nearer to:
  • $$X$$
  • $$C$$
  • equidistant
  • can't be predicted
Which of the following compounds will given racemic mixture on nucleophilic substitution by $$O{H}^{\ominus}$$ ion?
(a)  $$C{ H }_{ 3 }-\underset { \overset { | }{ { C }_{ 2 }{ H }_{ 5 } }  }{ CH } -Br$$
(b)  $$C{ H }_{ 3 }-\overset { \underset { | }{ Br }  }{ \underset { \overset { | }{ { C }_{ 2 }{ H }_{ 5 } }  }{ C }  } -C{ H }_{ 3 }$$
(c)  $$C{ H }_{ 3 }-\underset { \overset { | }{ { C }_{ 2 }{ H }_{ 5 } }  }{ CH } -C{ H }_{ 2 }Br$$
  • $$(a)$$
  • $$(a), (b), (c)$$
  • $$(b), (c)$$
  • $$(a), (c)$$
Alkyl halide can be converted into alkene by:
  • nucleophilic substitution reaction
  • elimination reaction
  • both nucleophilic substitution and elimination reaction
  • rearrangement
Benzene reacts with chlorine in presence of light to yield:
  • chlorobenzene
  • trichlorobenzene
  • tetrachlorobenzene
  • benzenehexachloride
Which of the following has strongest carbon - halogen bond ?
  • $$C{ H }_{ 3 }Cl$$
  • $$C{ H }_{ 3 }Br$$
  • $$C{ H }_{ 3 }F$$
  • $$C{ H }_{ 3 }I$$
$$CH_3-\underset{CH_3}{\underset{|}{\overset{CH_3\!\!\!\!\!\!}{\overset{|}{C}}}-}CH_2-\overset{CH_3}{\overset{|}{C}H}-CH_3$$      $$\xrightarrow{Br_2/hu}$$

For the given reaction how many products are optically active (all isomers) :
  • 1
  • 2
  • 3
  • 4
Under identical conditions, the $$S_{N}1$$ reaction will occur most efficiently with:
  • tert-butyl chloride
  • 1-chlorobutane
  • 2-methyl-1-chloropropane
  • 2-chlorobutane
Following reaction,
$${({CH}_{3})}_{3}CBr+{H}_{2}O\longrightarrow {({CH}_{3})}_{3}COH+HBr$$ is an example of:
  • elimination rection
  • free radical substitution
  • nucleophilic substitution
  • electrophilic substitution
Which of the following compounds have highest melting point?
466954_c0ee80e59e4d4a249edcc61020d0eb4b.png
  • Only I
  • Only II
  • I and II
  • II and III
t-Butyl chloride preferably undergo hydrolysis by:
  • $$S_N 1$$ mechanism
  • $$S_N 2$$ mechanism
  • any of (A) and (B)
  • none of these
The false statement regarding alkane is :
  • this does not perform polymerization reaction.
  • this does not gives elimination reaction.
  • it does not disappear the colour of dilute $$KMnO_{4}$$ solution..
  • it does not decolourise bromine water.
Which of the following statements is incorrect regarding benzyl chloride ? 
  • It gives white precipitate with alcoholic $$AgNO_3$$.
  • It is an aromatic compound with substitution in the side chain.
  • It undergoes nucleophilic substitution reaction.
  • It is less reactive than vinyl chloride.
Alkanes having odd carbons cannot be prepared as a major product in:
(A) Wurtz reaction
(B) Frankland reaction
(C) Kolbe's electrolysis
(D) Sabatier - sendersen reaction
  • B, C and D
  • A, C and D
  • A, B and D
  • A, B and C
Which of the following statements about benzyl chloride is incorrect?
  • It is less reactive than alkyl halides
  • It can be oxidised to benzaldehyde by boiling with copper nitrate solution
  • It is a lachrymatory liquid and answers Beilstein's test
  • It gives a white precipitate with alcoholic silver nitrate
The monohalogen derivatives of alkanes are called:
  • alkene halide
  • haloalkanes
  • halogen alkyl
  • none of the above
Which of the following dihalides on hydrolysis with aqueous $$KOH$$ gives ethylene glycol?
  • Ethylene Chloride
  • Ethylidene Chloride
  • Isopropylidene Chloride
  • None of the above

The criteria for optical isomerism are:
  • the presence of at least one asymmetric carbon is essential
  • the optical rotation is due to asymmetric carbon
  • non-superimposible mirror image
  • all of the above

IUPAC name of the above compound is:
510416_4be8c8d7c4fc4a8ba622f27fbfbee07c.png
  • $$3$$-Chlorotoluene
  • $$4$$-Chlorotoluene
  • $$4$$-Methylchlorobenzene
  • $$3$$-Methylchlorobenzene
Haloarenes react with halogens in the presence of _________ as the catalyst to give ortho-para isomers.
  • ferric chloride
  • sodium chloride
  • potassium chloride
  • magnesium chloride
Which of the following molecule would have a carbon halogen bond most susceptible to nucleophilic substitution?
  • $$2$$-fluorobutane
  • $$2$$-chlorobutane
  • $$2$$-bromobutane
  • $$2$$-idobutane
Which of the following statement is correct?
  • The $$C-X$$ bond in haloalkanes is more polar than the $$C-X$$ in haloarenes.
  • The $$C-X$$ bond in haloalkanes is less polar than the $$C-X$$ in haloarenes.
  • Polarity of $$C-X$$ bond in haloalkane is equal to the polarity of $$C-X$$ bond in haloarenes
  • Polarity of $$C-X$$ bond in both depends on conditions.
Identify the correct statement about nomenclature of alkyl halide.
  • The monohalogen derivatives of alkanes are called as alkyl halides.
  • The common name of an alkyl halide is always written as two separate words.
  • In IUPAC system, the monohalogen derivatives of alkanes are named as haloalkanes.
  • All of above.

Which of the following is/are optically active compound/s?
  • n-Butyl bromide
  • sec-Butyl bromide
  • Isobutyl iodide
  • tert-Butyl chloride
Which of the following carbon-halogen bond is extremely  polar though nonionic among given alkyl halides?
  • $$C-F$$
  • $$C-Br$$
  • $$C-Cl$$
  • $$C-I$$
Which among the given haloalkanes develop colour when exposed to light?
  • $$R-Br$$ and $$R-Cl$$
  • $$R-I$$ and $$R-F$$
  • $$R-Cl$$ and $$R-Br$$
  • $$R-Br$$ and $$R-I$$
The difference in electronegativity of carbon-halogen bond is minimum in:
  • $$C-F$$
  • $$C-Cl$$
  • $$C-I$$
  • $$C-Br$$
$$C-X$$ bond is strongest in:
  • $$CH_3Cl$$
  • $$CH_3Br$$
  • $$CH_3F$$
  • $$CH_3I $$
In $$R-X$$ the bond length is maximum in:
  • $$C-F$$
  • $$C-Cl$$
  • $$C-Br$$
  • $$C-I$$
Physical properties of any compound depend largely on:
  • its mass
  • the type of intermolecular and intramolecular forces of attraction
  • both mass and type of intermolecular and intramolecular forces of attraction
  • none of the above
Which of the following is not true for $$S_N1$$ reaction?
  • Favoured by polar solvents.
  • $$3^o -$$ alkyl halides generally react through $$S_N1$$ reaction.
  • The rate of the reaction does not depend upon the molar concentration of the nucleophile.
  • $$1^o -$$ alkyl halides generally react through $$S_N1$$ reaction.
Dipole moment of chlorobenzene is less then cyclohexylchloride
  • True
  • False
Which of the following is not correct for haloalkanes?
  • Density is directly proportional to the mass of compound
  • Haloalkanes are slightly soluble in water
  • Boiling Point depends upon the intermolecular forces of attraction
  • None of these
The IUPAC name for tertiary butyl iodide is:
  • 4-iodobutane
  • 2-iodobutane
  • 1-iodo-3-methylpropane
  • 2-iodo-2-methylpropane
Arrange these haloalkanes in correct order of density:
  • $$CH_3I < C_2H_5I < C_3H_7I$$
  • $$CH_3I > C_2H_5I > C_3H_7I$$
  • $$CH_3I < C_2H_5I > C_3H_7I$$
  • $$CH_3I > C_2H_5I < C_3H_7I$$
Arrange the alkyl in decreasing order of their mass.
  • $$CH_3Cl > H_2O > CH_3Br$$
  • $$CH_3Cl>CH_3Br>H_2O$$
  • $$CH_3Br> CH_3Cl > H_2O $$
  • $$H_2O > CH_3Cl > CH_3Br$$
Arrange in correct order of density:
  • $$CH_2Cl_2 < CHCl_3 < CCl_4$$
  • $$CH_2Cl_2 > CCl_4 > CHCl_3$$
  • $$CCl_4 < CH_2Cl_2 < CHCl_3$$
  • $$CH_2Cl_2 > CCl_4 < CHCl_3$$
Choose the correct order of bond strength:
  • $$CH_3F > CR_3Cl > CR_3Br > CH_3I$$
  • $$CH_3F < CR_3Cl < CR_3Br < CH_3I$$
  • $$CH_3F > CR_3Cl > CR_3Br < CH_3I$$
  • $$CH_3F > CR_3Cl < CR_3Br < CH_3I$$
Haloalkane in the presence of alcoholic $$KOH$$ undergoes:
  • elimination
  • polymerisation
  • dimerisation
  • substitution
Pure form of alkyl halide is:
  • odourless
  • colourless
  • both colourless and odourless
  • neither colourless nor odourless
Halide containing halogen attached to $$sp^3$$ carbon is/are: 
  • allylic halide
  • vinylic halide
  • benzylic halide
  • aryl halide
Which of the following does not exist in solid state at room temperature?
  • $$1,4-$$dichlorobenzene
  • $$1,3-$$dichlorobenzene
  • $$1,2-$$dichlorobenzene
  • All of the above
The only methyl halide which is a liquid is at room temperature is :
  • iodomethane
  • bromomethane
  • chloromethane
  • fluoromethane
Which is used as an anaesthetic during surgery?
  • Chloroquine
  • Thyroxine
  • Halothane
  • Chloramphenicol
Halide containing halogen attached to $$sp^2$$ carbon is/are: 
  • allylic halide
  • benzylic halide
  • aryl halide
  • vinyl halide
Alkyl halides develop colour on:
  • addition of water
  • addition of non polar solvent
  • exposure to light
  • exposure to air
Which of the following statements is correct about halogens?
  • they are all capable of exhibiting more than one oxidation states
  • they are all diatomic and form diatomic ions
  • they are all diatomic and form univalent ions
  • they are all reducing agents
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