CBSE Questions for Class 12 Engineering Chemistry Haloalkanes And Haloarenes Quiz 10 - MCQExams.com

The product obtained on reaction of $$C_2 H_5 Cl$$ with hydrogen over palladium carbon is: 
  • $$C_3H_8 $$
  • $$ C_4H_{10} $$
  • $$ C_2H_6 $$
  • $$ C_2H_4 $$
Chloroform on treatment with phenol in presence of caustic alkali forms salicylaldehyde. This reaction is known as: 
  • Carbylamine reaction
  • Cannizzaro's reaction
  • Wurtz-Fittig reaction
  • Reimer-Tiemann reaction
The lowest molecular weight alkanes, which are optically active; are
  • 3-methylhexane
  • 2,3-dimethylpentane
  • 2, 3, 3-trimethylbutane
  • 2-methylhexane
Which of the following molecules will not show optical activity?
The IUPAC name of Westron is:
  • 1,1,2,2-tetrachloroethane
  • 1,1,2,2-tetrachloroethene
  • 1,2-dichloroethyne
  • 1,3,3,3-tetrachloroprop-l-yne
The given reaction is:

1717896_19429599fe2e4d3e8d3554f21bf18d44.PNG
  • $$ S_{N^1} $$
  • $$ S_{N^2} $$
  • $$ E_1 $$
  • $$ E_2 $$
2-Chloro-2methylpropane on reaction with alc. KOH gives X as the product. X is.
  • but-2-ene
  • 2-methylbut-1-ene
  • 2-methylprop-1-ene
  • 2-methylbutane-2-ol
 The correct order of reactivity of following alkyl halides for $$ S_{N^1} $$ reaction is: 
  • $$ R-I> R-Br>R-Cl> R-F $$
  • $$ R-F>R-Cl>R-Br>R-I$$
  • $$ R-F>R-Br>R-Cl >R-I$$
  • $$R-Cl>R-I>R-Br>R-F$$
Which of the following reactions will yield $$2, 2-dibromo-propane$$?
  • $$H_{2}C = CHBr + HBr$$
  • $$CH_{3}C \equiv CCH_{3} + 2HBr$$
  • $$CH_{3}C \equiv CH + 2HBr$$
  • $$CH_{3}CH = CHBr + HBr$$
Allyl chloride is more reactive than vinyl chloride. 
  • True
  • False
In the following reaction, the major product $$'X'$$ is
1726671_798477b391864731bb23b9b82dbdf287.jpg
Identify $$'B'$$ in the following reaction
1726564_59498d34218746549f413e461547d4ea.jpg
  • None of these
In the halogenation of aromatic nucleus, the halogen carrier, is used to generate the species.
  • $$Cl\bullet$$
  • $$Cl^{+}$$
  • $$Cl^{-}$$
  • $$Cl$$
The product of the following reaction $$C_{6}H_{6} + Cl_{2} \xrightarrow {Sunlight} ?$$; is
  • $$C_{6}H_{5}Cl$$
  • Ortho $$C_{6}H_{4}Cl_{2}$$
  • $$C_{6}H_{6}Cl_{6}$$
  • Para $$C_{6}H_{4}Cl_{2}$$
In Raschig's process for the preparation of chlorobenzene, the reactants are
  • $$C_{6}H_{6}$$ and $$Cl_{2}$$
  • $$C_{6}H_{5}OH$$ and $$PCl_{5}$$
  • $$C_{6}H_{6} + HCl + O_{2}$$
  • $$C_{6}H_{5}OH$$ and $$HCl$$
In the presence of iron catalyst, benzene reacts with chlorine to form
  • Chlorobenzene
  • Benzene hexachloride
  • Hexachlorobenzene
  • None of these
Halogenation of alkanes is
  • A reductive process
  • An oxidative process
  • An isothermal process
  • An indothermal process
Which of the following is the example of $$SN^2$$ reaction
  • $$CH_3 Br + OH^-  - CH_3OH + Br^-$$
  • $$CH_3 CH \underset{Br}{\underset{|}{CH_3}} + OH^- \rightarrow CH_3 \underset{OH}{\underset{\!\!\!\!\!|}{CH}}CH_3 + Br^-$$
  • $$CH_3 CH_2 OH \xrightarrow{-H_2O} CH_2 = CH_2$$
  • $$CH_3 - \underset{Br}{\underset{|}{\overset{CH_3\!\!\!\!\!}{\overset{|}{C}}}} - CH_3 + OH^- \rightarrow CH_3 - \underset{H}{\underset{|}{\overset{CH_3\!\!\!\!\!}{\overset{|}{C}}}} - O - CH_3 + Br^-$$
Stilbene $$(PhCH=CHPh)$$ can exist in two diastereomeric forms $$(X)$$ and $$(Y)$$, and $$(X)$$ is found to be more soluble in water than $$(Y)$$. Predict which of the following statement is correct. 
  • $$X$$ is trans isomer
  • Stability of $$X >$$ stability of $$Y$$
  • Melting point of $$X <$$ melting point of $$Y$$
  • Boiling point of $$X <$$ boiling point of $$Y$$
The reaction
$$CH_3CH=CH_3\xrightarrow[H^{+}]{CO+H_{2}O}CH_{3}-CH-CH_{3}$$
 
$$COOH$$
 
is known as
  • Wurtz reactions
  • Koch reaction
  • Clemensons reduction
  • Kolbes reaction
When ethyl chloride and alcoholic $$KOH$$ are heated , the compound obtained is
  • $$C_2H_4$$
  • $$C_2H_2$$
  • $$C_6H_6$$
  • $$C_2H_6$$
Which of the following is liquid at room temperature
  • $$CH_3I$$
  • $$CH_3Br$$
  • $$C_2H_5Cl$$
  • $$CH_3F$$
When benzene is heated with chlorine in the presence of sunlight , it forms
  • $$B.H.C.$$
  • Cyclopropane
  • p - dichlorobenzene
  • None of these
Which metal is used in Wurtz synthesis
  • $$Ba$$
  • $$Al$$
  • $$Na$$
  • $$Fe$$
If the light waves pass through a nicol prism then all the oscillations occur only in one plane such beam of light is called as
  • Non polarised light
  • Plane polarised light
  • polarised light
  • Optical light
What is the major product of the following reaction $$CH_{3}C\equiv C-CH_{2}-CH_{3}\xrightarrow[]{1 \,mole \,of \,Cl_{2}}$$
  • $$CH_{3}-CH_{2}-\overset{Cl}{\overset{|}{\underset{Cl}{\underset{|}{C}}}}-CH_{2}CH_{3}$$
  • $$CH_{3}-\overset{Cl}{\overset{|}{\underset{Cl}{\underset{|}{C}}}}-\overset{Cl}{\overset{|}{\underset{Cl}{\underset{|}{C}}}}-CH_{2}CH_{3}$$
The reaction of benzene with chlorine in the presence of iron gives
  • Benzene hexachloride
  • Chlorobenzene
  • Benzyl chloride
  • Benzoyl chloride
(i) Chlorobenzene and (ii) benzene hexachloride are obtained from benzene by the reaction of chlorine, in the presence of
  • (i) Direct sunlight and (ii) anhydrous $$AlCl_{3}$$
  • (i) Sodium hydroxide and (ii) sulphuric acid
  • (i) Ultraviolet light and (ii) anhydrous $$FeCl_{3}$$
  • (i) Anhydrous $$AlCl_{3}$$ and (ii) direct sunlight
The major amount of $$(C)$$ is:
1768328_dc1c9dd18d9d4d268c85d53e9fa33e80.png
What would be the product formed when $$1$$-bromo-$$3$$-chloro cyclobutane reacts with two equivalents of metallic sodium in ether ?  
Condition for maximum yeild of $$C_2H_5Cl$$ is
  • $$C_2H_6 (\text{excess}) + Cl_2\xrightarrow[]{\text{UV Light}}$$
  • $$C_2H_6 + Cl_2 \xrightarrow[\text{Room temp.}]{\text{Dark}}$$
  • $$C_2H_6 + Cl_2$$ (excess) $$ \xrightarrow[]{\text{UV Light}}$$
  • $$C_2H_6 + Cl_2 \xrightarrow[]{\text{UV Light}}$$
The compounds are optically inactive because
1772137_384c29821b3b47b3931a41512124a8a4.png
  • Both compounds have the plane of symmetry
  • Both compounds have the centre of symmetry
  • Compound I has the plane of symmetry, while compound II has the centre of symmmtry.
  • Compound I has the centre of symmetry, while compound II has the plan of symmmtry.
Arrange the following in the decreasing order of nucleophilic acyl substitution reaction.
1770626_c90f339cf3aa4982943d103a6e611ea7.png
  • (I)>(II)>(III)>(IV)
  • (IV)>(III)>(II)>(I)
  • (I)>(III)>(II)>(IV)
  • (IV)>(II)>(III)>(I)
Statement 1: $$S_{N}1$$ reaction is carried out in the presence of polar protic solvents. 
Statement 2: Polar protic solvent increases the stability of carbocation due to the solvation.

Read the above statements and choose the correct option regarding it.
  • Statement 1 and Statement 2 are correct and Statement 2 is the correct explanation for Statement 1.
  • Statement 1 and Statement 2 are correct and Statement 2 is not the correct explanation for Statement 1.
  • Statement 1 is correct and Statement 2 is wrong.
  • Statement 1 is wrong and Statement 2 is correct.
$$CH_3-CH_3\xrightarrow[]{Br_2/hv}A\xrightarrow[]{LiAlH_4}B\xrightarrow[]{Br_2/hv}C\xrightarrow[]{Na/ether}D$$

The compound $$D$$ is:
  • $$CH_{3}-CH_{2}-CH_{2}-CH_{3}$$
  • $$CH_{3}-CH_{2}-O-CH_{2}-CH_{3}$$
  • $$CH_{3}-CH(CH_{3})-CH(CH_{3})-CH_{3}$$
  • $$CH_{3}-CH_{2}-CH_{3}$$
$$CH_3-CH(Br)-CH_3\xrightarrow[]{alc.\,KOH} A\xrightarrow[peroxide]{HBr}B\xrightarrow[acetone]{NaI}C$$

The compound $$C$$ is:
  • $$CH_{3}-CH_{2}-CH_{2}-I$$
  • $$CH_{3}-CH(I)-CH_{3}$$
  • $$CH_{3}-CHI-CH_{2}-I$$
  • $$CH_{3}-CH=CH-I$$
The compound $$Y$$ is:

15363.png
  • 1, 3 - dichloro benzene
  • benzyl chloride
  • 1, 3, 5 - trichloro benzene
  • mixture of 1, 2 and 1, 4 dichlorobenzene
Which one of the following compounds is most reactive for aromatic electrophilic substitution reaction?
  • $$C_{6}H_{5}-F$$
  • $$C_{6}H_{5}-Cl$$
  • $$C_{6}H_{5}-I$$
  • $$C_{6}H_{5}-NO_{2}$$
Assertion: Aryl halides undergo electrophilic substitution more readily than benzene.
Reason: Aryl halide gives a mixture of $$o -, p -$$ products when they undergo electrophilic substitution.
  • Assertion and Reason are correct and Reason is the correct explanation of Assertion
  • Assertion and Reason are correct but Reason is not the correct explanation of Assertion
  • Assertion is true and Reason is false
  • Assertion is false and Reason is true
The final product C, obtained in this reaction,would be :
69757_69218c9af6ef4ad89817e6fa5bddc517.png
In comparison to $$C-Cl$$ bond in ethyl chloride, the $$C-Cl$$ bond in vinyl chloride is:
  • longer and weaker
  • shorter and weaker
  • longer and stronger
  • shorter and stronger
For the compounds  $$CH_3Cl, CH_3Br, CH_3I$$ and $$CH_3F$$, the correct order of increasing C-halogen bond length is:
  • $$CH_3F < CH_3Cl < CH_3Br < CH_3I$$
  • $$CH_3F < CH_3Br < CH_3Cl < CH_3I$$
  • $$CH_3F < CH_3I < CH_3Br < CH_3Cl$$
  • $$CH_3Cl < CH_3Br < CH_3F < CH_3I$$
$$CH_3-CH_2-CH_2-O-\underset{S}{\underset{||}{C}}-S-CH_3$$ undergoes elimination on strong heating giving $$CH_3-CH=CH_2, CH_3SH$$ and $$COS$$. This reaction involves :
  • formation of cyclic intermediate
  • syn elimination
  • anti elimination
  • first order kinetics
Which of the following method would be better for the synthesis of 1-bromo-3-ethylbenzene?
One of the iosmers of $$C_{4}H_{9}Cl$$ by Wurtz reaction forms $$2,2,3,3$$- tetramethylbutane. The structure of that isomer of $$C_{4}H_{9}Cl$$:
  • $$1$$-Chloro - $$2$$- methylpropane
  • $$2$$-Chloro - $$2$$- methylpropane
  • $$2$$-Chloro butane
  • $$1$$-Chlorobutane
$$1-$$bromo$$-3-$$chlorocyclobutane when treated with two equivalents of $$Na$$, in the presence of ether which of the  following will be formed? 
Select the best combination of regents which will bring the following conversion.
116626.png
  • $$Br_2/FeBr_3; \;HNO_3/H_2SO_4;\ NaOH; \;H_2/Pt$$
  • $$CH_3COCl/AlCl_3; \;Br_2/FeBr_3;\; NaBH_4/CH_3OH$$
  • $$CH_3Cl/AlCl_3; \;KMnO_4; \;CH_3Cl/AlCl_3; \;NBS/hv;\;LiAiH_4/H_2O;\;NaOH$$
  • $$CH_3Cl/AlCl_3; \;HNO_3/H_2SO_4; \;NBS/hv/NaOH$$
The major product of the above shown reaction is :
116610.png
The most stable conformation of the product of following reaction is:
117493_3a88aec119f94459856c9d1cf8885a9c.png
Which of the following reaction will give Iodobenzene as the major organic product?
0:0:1


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