CBSE Questions for Class 12 Engineering Chemistry Haloalkanes And Haloarenes Quiz 8 - MCQExams.com

Which is the correct increasing order of bond dissociation enthalpy of $$C-X$$ bond?
  • $$C-F , C-Cl , C-Br , C-I$$
  • $$C-I , C-F , C-Cl , C-Br $$
  • $$C-Cl , C-F , C-Br , C-I$$
  • $$C-I , C-Br , C-Cl , C-F$$
$$CH_3 - CH_2 - Br \xrightarrow[\Delta]{Alco. KOH} B \xrightarrow{HBr} C\xrightarrow{Na/ether}D$$ the compound D is
  • ethane
  • propane
  • n-butane
  • n-pentane
The reaction of $$1-$$bromo$$-3-$$chlorocyclobutane with metallic sodium in dioxane gives:
Which of the following is allylic halide?
  • (1-Bromoethyl) benzene
  • Benzyl chloride
  • 1-Bromo benzene
  • 3-Chloro cyclohex-1-ene
Which of the following cycloalkane gives open chain compound when it reacts with bromine?
  • Cyclopropane
  • Cyclopentane
  • Cyclohexane
  • Cyclo-octane
$$C_6H_6+Cl_2(excess)\xrightarrow[dark,\, cold]{Anhy. Alcl_3}P$$
Product, $$P$$ is:
  • $${ C }_{ 6 }{ H }_{ 5 }Cl$$
  • $${ C }_{ 6 }{ H }_{ 4 }{ Cl }_{ 2 }$$
  • $${ C }_{ 6 }{ H }_{ 6 }{ Cl }_{ 6 }$$
  • $${ C }_{ 6 }{ Cl }_{ 6 }$$
Which of the following is the correct order for strength of $$C - X$$ bond ?
  • $$ CH_3F < CH_3Cl < CH_3Br < CH_3I$$
  • $$CH_3F > CH_3Cl >CH_3Br >CH_3I$$
  • $$CH_3I>CH_3F > CH_3Cl > CH_3Br$$
  • $$CH_3Cl > CH_3Br > CH_3F >CH_3I$$
On mixing alkane with chlorine and irradiating with ultraviolet light, it forms only one monochloro alkane. The alkane is: 
  • propane
  • pentane
  • isopentane
  • neopentane
Which of the following cannot undergo $$E_2$$ reaction?
  • None of these
The correct order of reactivity of the halides,
(I) ethyl chloride; (II) isopropyl chloride and (III) benzyl chloride in $$S_N 1 $$ reaction is:
  • $$I > II > III$$
  • $$III > II > I$$
  • $$II > I > III$$
  • $$I > III > II$$

The products formed in the reaction is(are):
  • ethane, propane
  • butane
  • phrpane
  • ethane, propane, butane
The major product is:
691605_f513af273aea4c5193c6672e00c42b4b.png
The treatment of $${R}_{3}MgX$$ with ethyl formate leads to the formation of:
  • $$RCHO$$
  • $${ CH }_{ 3 }{ CH }_{ 2 }OR$$
  • $$RCHOH{ C }_{ 2 }{ H }_{ 5 }$$
  • $${ C }_{ 2 }{ H }_{ 5 }OH\quad $$
The compound 
$$ C_7 H_8 \xrightarrow { 3Cl_2/\triangle  } X\xrightarrow { Br_2/Fe } Y\xrightarrow { Zn/HCl } Z$$
The compound $$Z$$ is :
  • m-bromotoluene
  • p-bromotoluene
  • o-bromotoluene
  • 2, 4, 6-trichlorotoluene
.
712220_5bc04504a8f541c08d87ab98325328f3.png
Arrange the following alkyl chlorides in order of decreasing reactivity in a $$S_N1$$ reaction.
(I) isopropyl bromide 
(II) propyl bromide
(III) tert-butyl bromide
(IV) methyl bromide 
  • (III) > (I) > (II) > (IV)
  • (I) > (III) > (IV) > (II)
  • (IV) > (III) > (II) > (I)
  • (I) > (II) > (III) > (IV)
The best yield of given product can be obtained by using which set of reactants $$X$$ and $$Y$$ respectively
789203_704744daf5fa414581a0723f9de84ca5.PNG
  • $$PhLi+$$ Neopentyl chloride
  • $$PhMgBr+$$ Neopentyl bromide
  • $$t-Bu+MgBr+$$ Benzyl bromide
  • Benzylchloride$$+$$ t-Butyl chloride
$$CH_3.CH_2O\overset{CH_3}{\overset{|}{C}}H.CH_2.CH_2CH_2Cl$$
The correct IUPAC name of the given compound is:
  • 2-ethoxy-5-chloropentane
  • 1-chloro-4-ethoxy-4-methylbutane
  • 1-chloro-4-ethoxypentane
  • ethyl-1-chloropentylether
The product formed in the reaction is:
758884_b0344af8561d4c70a2ea120cd9721e88.png
  • $$(BrCH_{2})_{3}CCH_{2}CH_{2}C(CH_{2}Br)_{3}$$
Which of the following will be most reactive for $$S_N1$$ reaction?
  • $$(CH_3)_3C-Cl$$
  • $$(CH_3)_2CH-Cl$$
  • $$(CH_3)_2N-CH_2Cl$$
  • $$(CH_3)_3C-Br$$
Which does not have conjugate system?
  • $$CH_{2} = CHCl$$
  • $$CH_{2} = CHCHO$$
  • $$CH_{3}CH = CH_{2}$$
During the course of an $$S_N1$$ reaction, the intermediate species formed is:
  • a carbocation
  • a free radical
  • a carbanion
  • an intermediate complex
Which one of the following is best catalyst for the reaction shown below ?
$${ CH }_{ 3 }({ CH }_{ 2 }{ ) }_{ 8 }{ CH }_{ 2 }{ Br }\overset { KCN }{ \underset { benzene }{ \longrightarrow  }  } { CH }_{ 3 }({ CH }_{ 2 }{ ) }_{ 8 }{ CH }_{ 2 }CN$$
Which of the following compounds is optically active?
Among the following, the optically inactive compound is :
Specific rotation is the rotation produced by $$1$$g of material in $$1$$ml of liquid in a $$1$$ dm tube. Which of the following molecules have largest value of specific rotation? (Hint : Molecular mass increasing).
The IUPAC name of $$(CH_3)_2CH-CH_2-CH_2Br$$ is ?
  • 1-bromopentane
  • 1-bromo-3-methylbutane
  • 2-methyl-4-bromobutane
  • 2-methyl-3-bromopropane
Arrange the following alkyl halides in decreasing order of the rate of $$\beta$$- elimination reaction with alcoholic KOH.
$${ CH }_{ 3 }{ CH }_{ 2 }{ CH }_{ 2 }Br\quad { CH }_{ 3 }-\underset { \underset { { \displaystyle \,\,\,\,CH }_{ 3 } }{ | }  }{ CH } -{ CH }_{ 2 }Br\quad { CH }_{ 3 }-{ CH }_{ 2 }-\underset { \underset {\displaystyle Br }{ | }  }{ CH } -{ CH }_{ 3 }\quad $$
(i)                                                   (ii)                                                     (iii)
  • $$(ii) > (iii) > (i)$$
  • $$(iii) > (ii) > (i)$$
  • $$(i) > (ii) > (iii)$$
  • $$(ii) > (i) > (iii)$$
The IUPAC name of tertiary butyl chloride is ?
  • 2-chloro-2-methylpropane
  • 3-chlorobutane
  • 4-chlorobutane
  • 1, 2-chloro-3-methylpropane.
The reaction of Sodium methoxide with $${R}_{2}CHX$$ is:
  • $${SN}^{1}$$
  • $${SN}^{2}$$
  • Elimination
  • Substitution
The reaction proceeds with 98% racemisation. The reaction may follow:

937569_100101ae2bd245f9b37b28b9f627b43c.PNG
  • $$S_N1$$ mechanism
  • $$S_N2$$ mechanism
  • E1 mechanism
  • E2 mechanism
Choose the correct answer among the alternatives given :Bromination of methane in presence of sunlight is a:
  • nucleophilic substitution
  • free radical substitution
  • electrophilic substitution
  • nucleophilic addition
Which of the following is not correctly matched with its IUPAC name?
  • $$CHF_2CBrClF$$ : 1-Bromo-1-chloro-1, 2, 2 -trifluoroethane
  • $$(CCl_3)_3CCl$$ : 2-(Trichloromethyl)-1,1,1,2,3,3, 3 -heptachioropropane
  • $$CH_3C(p-ClC_6H_4)_2CH(Br)CH_3$$ : 2-Bromo-3,3-bis(4-chlorophenyl) butane
  • $$o-BrC_6H_4CH(CH_3)CH_2CH_3$$ : 2-Bromo-1-methylpropylbenzene
Choose the correct option from the following:
  • In the electrophilic substitution of toluene with $$Br_2$$, iron (III) bromide acts as a Lewis acid.
  • In the reaction of toluene with $$Cl_2/FeCl_3$$, ortho and para isomers are easily separated.
  • Similar reaction with iodine is reversible in nature
  • All of these
A compound X with molecular formula $$C_7H_8$$ is treated with $$Cl_2$$ in presence of $$FeCl_3$$. Which of the following compounds are formed during the reaction?
Which of the following is the most reactive towards nucleophilic substitution reaction?
  • $$ClCH_2-CH=CH_2$$
  • $$CH_2=CH-Cl$$
  • $$CH_3CH=CH-Cl$$
  • $$C_6H_5Cl$$
The reaction of toluene with chlorine in the presence of iron and in the absence of light yields ________.
  • mixture of (b) and (c)

Choose the correct answer among the alternatives given :

In the following pairs of halogen compounds , which compound undergoes faster $$S_N1$$ reaction?

937599_6c8a0fded3b14c4f8a4a7346f61ea0ba.png
Reaction of $$C_6H_5CH_2Br$$ with aqueous sodium hydroxide follows ___________.
  • $$S_N1$$ mechanism
  • $$S_N2$$ mechanism
  • Any of the above two depending upon the temperature of reaction
  • Saytzeff rule
Chlorobenzene is formed by reaction of chlorine with benzene in the presence of $$A1C1_3$$.Which of the following species attacks the benzene ring in this reaction?
  • $$C1^-$$
  • $$Cl^+$$
  • $$AlCl_3$$
  • $$[AlCl_4]^-$$
Which is the correct IUPAC name for,

$$CH_3-{\underset{C_2H_5}{\underset{|}{CH}}}-CH_2-Br$$:
  • 1-Bromo-2-ethylpropane.
  • 1-Bromo-2-ethyl-2-methylethane.
  • 1-Bromo-2-methylbutane.
  • 2-Methyl-1-bromobutane.
For the given Question (1,2,3)  consider the following reaction.
Which halogen will give the best yield of a single monohalogenation product ?
988826_7e2fbd3531ee403d881feb5b49d95d2c.PNG
  • $$F_2$$
  • $$Cl_2$$
  • $$Br_2$$
  • $$I_2$$
Chloromethane  on treatment with excess of ammonia yields mainly :
  • N, N-dimethylmethanamine
  • N-methylmethanamine $$(CH_3-NH-CH_3)$$
  • methanamine $$(CH_3NH_2)$$
  • mixture containing all these in equal proportion.
Alkyl halides react with metallic sodium in dry ether producing?
  • Alkanes with same number of carbon atoms
  • Alkanes with double number of carbon atoms
  • Alkenes with triple number of carbon atom
  • Alkenes with same number of carbon atom
What should be the correct IUPAC name for diethylbromomethane?
  • 1 - Bromo- 1, 1 - diethylmethane
  • 3 - Bromopentane
  • 1 - Bromo-1 - ethylpropane
  • 1 - Bromopentane
Which of the following reactants is suitable for preparation of methane and ethane by using one step only?
  • $$H_2C = CH_2$$
  • $$CH_3OH$$
  • $$CH_3-Br$$
  • $$CH_3-CH_2-OH$$
Additional of $$Br_2$$ to trans-2- butene would give a product which is :
  • achiral
  • racemic
  • meso
  • optically active
Rank in the order of increasing acidic strength:
989427_63e1775a91b94959b8f7da8cb92ff238.PNG
  • $$A < B < C$$
  • $$A < C < B$$
  • $$B < A < C$$
  • $$B < C < A$$
Match the column I with column II and with column III.
988890_4811ec6132474d26a6c57f63f624ea98.png
  • a - q - w; b - s - x; c - p - y; d - q - z
  • a - b - x; q - s - z; c - p - w; d - q - x
  • a - q - x; b - s - z; c - p - w; d - q - x
  • a - s - x; b - p - z; c - q - w; d - q - x
$$\underrightarrow{AgNO_3} (A)$$;
Which statement is incorrect in respect of the above reaction?
988889_5567135824f14c8dbace5e70f2f5c647.PNG
  • Product is aromatic
  • product has high dipole moment
  • Product has less resonance energy
  • Product is soluble in polar-solvent
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