CBSE Questions for Class 12 Engineering Chemistry Haloalkanes And Haloarenes Quiz 5 - MCQExams.com

In which of the following can $$C-Cl$$ bond be easily broken?
  • Chlorobenzene
  • Vinyl chloride
  • Allyl chloride
  • p-Chlorotoluene
The reagents required for the following two-step transformation are?
790839_8a99c939280a4a9f837c60d8485ea0b0.jpg
  • (i) $$HBr$$, benzoyl peroxide, (ii) $$CH_3CN$$
  • (i) $$HBr$$, (ii) $$NaCN$$
  • (i) $$Br_2$$; (ii) $$NaCN$$
  • (ii) $$NaBr$$; (ii) $$NaCN$$
Which of the following is most reactive towards the $${ S }_{ N }1$$ reaction?
  • A and B reacts at similar rate
Which of the following reaction is used to increase the length of the carbon chain ?
  •  Clemmensen reduction
  • Wolff-Kishner Reduction
  • Wurtz reaction
  • Kolbe’s electrolysis
Which of the following is used in paint removing?
  • $$CHCl_{3}$$
  • $$CH_{2}Cl_{2}$$
  • $$CCl_{4}$$
  • $$CH_{3}Cl$$
In chlorination of benzene in presence of $$ FeCl_{3}$$, function of $$ FeCl_{3}$$ is :
  • to provide halogen.
  • to form electrophile.
  • resonance stabilisation.
  •  act as a catalyst.
$$2C_{6}H_{5}Cl+2Na\rightarrow X$$
In the given reaction $$X$$ is:
  • toulene
  • biphenyl
  • phenyl ethane
  • $$1$$-chloro-$$2$$-phenyl ethane
What is the hybridisation of carbon that is attached to chlorine atom in n-primary alkyl halide?
  • $$sp^3$$
  • $$sp^2$$
  • $$sp$$
  • $$sp^3d$$
$$CH_3-CH(Cl)-CH_2-CH_2-CH_3$$ and $$CH_3-CH_2-C(Cl)(CH_3)-CH_3$$ are both positional and chain isomerism of each other.
  • True
  • False
The reagent used for dehydrohalogenation is ____________.
  • $$H_2O_2$$
  • $$K_2SO_4$$
  • alcoholic $$KOH$$
  • none of the above
Alkyl halide reacting with metallic sodium in dry ether solution is called:
  • Friedel-crafts reaction
  • Sandmeyer reaction
  • Wurtz reaction
  • Gabriels reaction
Which of following will give syn-elimination?
  • $$\displaystyle CH_{3}-CH_{2}CH_{2}-OCOCH_{3}$$
  • $$CH_3CH_2\underset {Cl}{\underset{|}C}H-CH_3$$
  • $$CH_3CH_2CH_2-O-\underset {S} {\underset {||} C}-S-CH_3$$
The conversion (Image) Can be effected using
73370.jpg
  • $$Br_2/CCl_4$$
  • $$Br_2/H_2O$$
  • $$Br_2/Fe$$
  • $$Br_2/benzoyl peroxide$$
IUPAC name of  $$(CH_{3})_{2}CH - CH_{2} - CH_{2}Br$$  is:
  • 1-Bromopentane
  • 2-Methyl-4-bromobutane
  • 1-Bromo-3-methylbutane
  • 2-Methyl-3-bromobutane
The IUPAC name of the compound $$CH_3-CH(CH_3)-CH_2-CH_2Cl$$ is:
  • 1-chloro-3-methylbutane
  • 2-methyl-4-chlorobutane
  • 2-methyl-1-chlorobutane
  • 1-chloropentane
Which of the following undergoes nucleophilic substitution exclusively by $$S_N{1}$$ mechanism?
  • ethyl chloride
  • isopropyl chloride
  • benzyl chloride
  • chlorobenzene
Nature of $$C-X$$ bond is:
  • ionic
  • covalent
  • co-ordinate
  • none of these
Bond order of $$C-X$$ bond is $$1$$ because :
  • $$Cl$$ achieve noble gas configuration by sharing one electron
  • $$C$$ not able to form multiple bonds
  • $$Cl$$ does not have vacant orbitals
  • $$C$$ achieve noble gas configuration by sharing one electron
The main difference in C - X bond of a haloalkane and a haloarene is 
  • C - X bond in haloalkanes is shorter than haloarenes.
  • In haloalkanes the C attached to halogen in C - X bond is $$sp^{3}$$ hybridised while in haloarenes it is $$sp^{2}$$ hybridised.
  • C - X bond in haloarenes acquires a double bond character due to higher electronegativity of X than haloalkanes.
  • haloalkanes are less reactive than haloarenes due to difficulty in C - X cleavage in haloalkanes.
What is the correct IUPAC name for
1847553_2a345573c0e041f4b38cef1dbbb4bcf3.png
  • 1-Bromo-2-ethylpropane
  • 1-Bromo-2-ethyl-2-methylethane
  • 1-Bromo-2-methylbutane
  • 2-Methyl-1-bromobutane

Match the isomers given in column I with their names given in column II and mark the appropriate choice.
1847402_586aeae9c3fa489b97c68e8f54459554.PNG
  • $$(A) \rightarrow (iii), (B) \rightarrow (i), (C) \rightarrow (iv), (D) \rightarrow (ii)$$
  • $$(A) \rightarrow (iv), (B) \rightarrow (iii), (C) \rightarrow (ii), (D) \rightarrow (i)$$
  • $$(A) \rightarrow (i), (B) \rightarrow (ii), (C) \rightarrow (iii), (D) \rightarrow (iv)$$
  • $$(A) \rightarrow (ii), (B) \rightarrow (iii), (C) \rightarrow (iv), (D) \rightarrow (i)$$
Identify the products  X and Y formed in the following reaction:
$$CH_3-CH_2-CH = CH-CH_3 + HCl \rightarrow X + Y$$
In which of the following cases $$C-C$$ bond length will be the longest?
  • $$CH_3-CF_3$$
  • $$FCH_2-CH_2F$$
  • $$F_2CH-CHF_2$$
  • $$CF_3-CF_3$$
$$\displaystyle S_{N^1}$$ & $$\displaystyle S_{N^2}$$  product are same in (excluding stereoisomer):
  • $$Ph-\underset {CH_3} {\underset {|}CH}-\underset {Cl} {\underset {|}CH}-CH_3$$
The compound $$A$$ is :
128354.png
  • none of the above
Choose all alkane that give only one monochloro derivative upon reaction with chlorine in sun light.
Which of the following sequences would yield m-nitro chlorobenzene $$(Z)$$ from benzene?
  • Benzene $$\xrightarrow [ ]{ { Cl }_{ 2 }/Fe{ Cl }_{ 3 } } (X)\xrightarrow [ { H }_{ 2 }{ SO }_{ 4 } ]{ H{ NO }_{ 3 } } (Z)$$
  • Benzene $$\xrightarrow [ ]{ { H }_{ 2 }{ SO }_{ 4 }/H{ NO }_{ 3 } } (Z)$$
  • Benzene $$\xrightarrow [ ]{ { H }_{ 2 }{ SO }_{ 4 }/H{ NO }_{ 3 } } (X)\xrightarrow [ ]{ { Cl }_{ 2 }/Fe{ Cl }_{ 3 } } (Z)$$
  • All of these
Iso-propyl bromide on Wurtz reaction gives:
  • Hexane
  • Propane
  • 2, 3-dimethylbutane
  • Neo-hexane
2-phenylethylbromide when heated with $$NaOEt$$, elimination takes place. No deuterium exchange takes place when the reaction is carried out in $${C}_{2}{H}_{5}OD$$ solvent. The mechanism will be:
  • $$E1$$ elimination
  • $$E2$$ elimination
  • $$E1cB$$ elimination
  • $$E2$$ or $${E1}cB$$
Which one of the following undergoes nucleophilic substitution exclusively by $$S_N1$$ mechanism? 
  • Benzyl chloride
  • Ethyl chloride
  • Chlorobenzene
  • Isopropyl chloride
On commercial scale, phenol is obtained from chlorobenzene. The chlorobenzene needed for the purpose is prepared by:
  • Both Assertion and Reason are correct and Reason is the correct explanation for Assertion.
  • Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion.
  • Assertion is correct but Reason is incorrect.
  • Both Assertion and Reason are incorrect.
Which of the following halides undergoes nucleophilic substitution most readily? 
  • $$p- H_3CC_6H_4Cl$$
  • $$O- MeOC_6H_4Cl$$
  • $$p-ClC_6H_4Cl$$
  • $$C_6H_5CH(Cl)CH_3$$
Isopropyl bromide on Wurtz reaction gives:
  • hexane
  • propane
  • $$2, 3$$-dimethyl butane
  • neo-hexane
Which is the correct increasing order of electronegativity of halides?
  • $$F,Cl,Br,I$$
  • $$I,Br,Cl,F$$
  • $$Br,Cl,F,I$$
  • $$Cl,Br,I,F$$
Which of the following is used for metal cleaning and finishing?
  • $$CHCl_{3}$$
  • $$CHI_{3}$$
  • $$CH_{2}Cl_{2}$$
  • $$C_{6}H_{6}$$
$$C_{6}H_{13}Br + OH^{-} \longrightarrow C_{6}H_{13}OH + Br^{-}$$ is an example of:
  • Nucleophilic addition
  • Nucleophilic substitution
  • Electrophilic addition
  • Electrophilic substitution
  • Free radical substitution
The IUPAC name of haloalkane is always written as a ______ word. 
  • single
  • double
  • triple
  • none of these
Heating many alkyl chlorides or bromides in water effects their conversion into alcohol through a $$ S_{N}$$1 reaction. Order each of the following sets of compounds with respect to solvolytic reactivity.
127989.png
  • $$i>ii>iii$$
  • $$ii>i>iii$$
  • $$iii>ii>i$$
  • $$iii>i>ii$$
The ability of rotation of plane polarized light either towards right or left is called as:
  • optical activity
  • chirality
  • superimposibility
  • non superimposibility
Which of the following haloalkanes is most reactive?
  • 1-chloropropane
  • 1-bromopropane
  • 2-chloropropane
  • 2-bromopropane
In the dehydrohalogenation of ethyl chloride, which of the following change occurs?
  • $$sp^{2}$$ carbon converts to $$sp^{3}$$ carbon
  • $$sp^{2}$$ carbon converts to $$sp$$ carbon
  • $$sp^{3}$$ carbon converts to $$sp$$ carbon
  • $$sp^{3}$$ carbon converts to $$sp^{2}$$ carbon
Consider the following anions.

When attached to $$sp^{3}-$$hybridized carbon, their leaving group ability in nucleophilic substitution reaction decreases in the order :
989659_bf5196f5041e4a80b94e5c4555167660.png
  • $$I > II > III > IV$$
  • $$I > II > IV > III$$
  • $$IV > I > II > III$$
  • $$IV > III > II > I$$
Product $$(B)$$ is :
989614_903f5bc51bd041278c09a1459d6acddb.png
  • None of these
Arrange the following alkyl halides in decreasing order of the rate of $$\beta $$-elimination reaction with  alcoholic KOH.

$${ CH }_{ 3 }{ CH }_{ 2 }{ CH }_{ 2 }Br\\ \quad \quad \quad \quad \quad (i)$$   $${ CH }_{ 3 }-CH{ -CH }_{ 2 }Br\quad \\ \quad \quad \quad \ |\\ \quad \quad \ { CH }_{ 3 }\\ \quad \quad (ii)$$ $${ CH }_{ 3 }-{ CH }_{ 2 }{ -CH }-{ CH }_{ 3 }\quad \\ \quad \quad \quad \quad \quad \quad |\\ \quad \quad \quad \quad \quad \quad  Br\\ \quad \quad \quad \quad \quad (iii)$$
  • $$(ii)\quad >\quad (iii)\quad >\quad (i)$$
  • $$(iii)\quad >\quad (i)\quad >\quad (ii)$$
  • $$(i)\quad >\quad (ii)\quad >\quad (iii)$$
  • $$(ii)\quad >\quad (i)\quad >\quad (i)$$
Ortho and para hydrogen differ in 
  • atomic number
  • mass number
  • electron spin in two atoms
  • nuclear spin of two atoms
Follows
1265393_ad08b9a02e71437b80e828f04d96db85.png
  • $$E_2$$ mechanism
  • $$\epsilon _1$$ mechanism
  • $$S_N^1$$ mechanism
  • $$S_N^2$$ mechanism
Select whether the following combinations of reactants will react by substitution $$(S_{N^1} or S_{N^2}$$ mechanism), elimination ($$E_1 or E_2$$ mechanism).
$$(CH_3)_3C - OH \xrightarrow[25^0C]{HBr 48\% in H_2O}$$
  • $$S_{N^1}$$
  • $$S_{N^2}$$
  • $$E_1$$
  • $$E_2$$
$$S_N1$$ characteristic would be exhibited in the hydrolysis of;
  • Chlorobenzene
  • $$1$$-chloronapthalene
  • propenyl chloride
  • $$2$$-chloro-$$1$$-propene
Which of the following is an example of alkyl halide?
  • $$p-$$chlorotoluene
  • Chloro methane
  • Allyl chloride
  • Benzyl chloride
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