Electrophilic Aromatic Substitution (Haloalkanes and Haloarenes) MCQ Questions & Answers in Organic Chemistry | Chemistry

Learn Electrophilic Aromatic Substitution (Haloalkanes and Haloarenes) MCQ questions & answers in Organic Chemistry are available for students perparing for IIT-JEE, NEET, Engineering and Medical Enternace exam.

31. Which of the following order is not correct ?

A $$MeBr > M{e_2}CHBr > M{e_3}CBr$$       $$ > E{t_3}CBr\left( {{S_N}2} \right)$$
B $$PhC{H_2}Br > Ph\,CHBrMe > $$       $$PhCBrM{e_2} > PhCBrMePh\left( {{S_N}1} \right)$$
C $$MeI > MeBr > MeCl > MeF\left( {{S_N}2} \right)$$
D $${\text{All are correct}}$$
Answer :   $$PhC{H_2}Br > Ph\,CHBrMe > $$       $$PhCBrM{e_2} > PhCBrMePh\left( {{S_N}1} \right)$$

32. Match the column I with column II and mark the appropriate choice.
Column I Column II
a. $$C{H_3}CHC{l_2}$$ 1. Vinyl halide
b. $$C{H_2}ClC{H_2}Cl$$ 2. Alkylidene halide
c. $$CHCl = C{H_2}$$ 3. Alkylene dihalide
d. $$ClC{H_2} - CH = C{H_2}$$ 4. Allyl halide

A a - 1, b - 2, c - 4, d - 3
B a - 2, b - 3, c - 1, d - 4
C a - 3, b - 4, c - 2, d - 1
D a - 4, b - 1, c - 3, d - 2
Answer :   a - 2, b - 3, c - 1, d - 4

33. Among the given halides, which one will give same product in both $${S_N}1$$  and $${S_N}2$$  reactions ?
Electrophilic Aromatic Substitution (Haloalkanes and Haloarenes) mcq question image

A (III) only
B (I) and (II)
C (III) and (IV)
D (I), (III) and (IV)
Answer :   (III) and (IV)

34. Arrange the following compounds in decreasing order of their boiling points.
$$\eqalign{ & \left( {\text{i}} \right)C{H_3}Br \cr & \left( {{\text{ii}}} \right)C{H_3}C{H_2}Br \cr & \left( {{\text{iii}}} \right)C{H_3}C{H_2}C{H_2}Br \cr & \left( {{\text{iv}}} \right)C{H_3}C{H_2}C{H_2}C{H_2}Br \cr} $$

A (i) > (ii) > (iii) > (iv)
B (iv) > (iii) > (ii) > (i)
C (i) > (iii) > (ii) > (iv)
D (iii) > (iv) > (i) > (ii)
Answer :   (iv) > (iii) > (ii) > (i)

35. The major product formed in the following reaction is
\[C{{H}_{3}}\underset{\begin{smallmatrix} | \\ H \end{smallmatrix}}{\overset{\begin{smallmatrix} \,\,\,\,\,C{{H}_{3}} \\ | \end{smallmatrix}}{\mathop{-C-}}}\,C{{H}_{2}}Br\xrightarrow[C{{H}_{3}}OH]{C{{H}_{3}}{{O}^{-}}}\]

A \[C{{H}_{3}}\underset{\begin{smallmatrix} | \\ H\, \end{smallmatrix}}{\overset{\begin{smallmatrix} \,\,\,\,\,C{{H}_{3}} \\ | \end{smallmatrix}}{\mathop{-C-}}}\,C{{H}_{2}}OC{{H}_{3}}\]
B \[C{{H}_{3}}\underset{\begin{smallmatrix} |\,\,\,\, \\ \,\,\,OC{{H}_{3}} \end{smallmatrix}}{\mathop{-CH-}}\,C{{H}_{2}}C{{H}_{3}}\]
C \[C{{H}_{3}}-\overset{\begin{smallmatrix} \,C{{H}_{3}} \\ |\,\,\,\,\, \end{smallmatrix}}{\mathop{C=}}\,C{{H}_{2}}\]
D \[C{{H}_{3}}\underset{\begin{smallmatrix} | \\ \,\,\,\,\,\,OC{{H}_{3}} \end{smallmatrix}}{\overset{\begin{smallmatrix} \,\,\,\,C{{H}_{3}} \\ | \end{smallmatrix}}{\mathop{-C-}}}\,C{{H}_{3}}\]
Answer :   \[C{{H}_{3}}\underset{\begin{smallmatrix} | \\ \,\,\,\,\,\,OC{{H}_{3}} \end{smallmatrix}}{\overset{\begin{smallmatrix} \,\,\,\,C{{H}_{3}} \\ | \end{smallmatrix}}{\mathop{-C-}}}\,C{{H}_{3}}\]

36. Which of the following statements is correct?

A In the electrophilic substitution of toluene with $$B{r_2},$$  iron (III) bromide acts as a Lewis acid.
B In the reaction of toluene with $$\frac{{C{l_2}}}{{FeC{l_3}}},ortho$$    and $$para$$  isomers are easily separated.
C Similar reaction with iodine is reversible in nature.
D All of these
Answer :   All of these

37. Which of the following compounds will have highest melting point?

A Chlorobenzene
B $$o$$ - Dichlorobenzene
C $$m$$ - Dichlorobenzene
D $$p$$ - Dichlorobenzene
Answer :   $$p$$ - Dichlorobenzene

38. The reaction of toluene with chlorine in presence of ferric chloride gives predominantly :

A benzoyl chloride
B $$m $$ - chlorotoluene
C benzyl chloride
D $$o $$ - and $$p $$ - chlorotoluene
Answer :   $$o $$ - and $$p $$ - chlorotoluene

39. Which of the following statements regarding the $${S_N}1$$  reaction shown by alkyl halide is not correct?

A The added nucleophile plays no kinetic role in $${S_N}1$$  reaction.
B The $${S_N}1$$  reaction involves the inversion of configuration of the optically active substrate.
C The $${S_N}1$$  reaction on the chiral starting material ends up with racemisation of the product.
D The more stable the carbocation intermediate the faster the $${S_N}1$$  reaction.
Answer :   The $${S_N}1$$  reaction involves the inversion of configuration of the optically active substrate.

40. Arrange the following compounds in order of their reactivity towards $${S_N}2$$  reaction.
\[\begin{align} & \left( \text{i} \right)C{{H}_{3}}{{\left( C{{H}_{2}} \right)}_{3}}C{{H}_{2}}Br \\ & \left( \text{ii} \right){{\left( C{{H}_{3}} \right)}_{2}}CHC{{H}_{2}}C{{H}_{2}}Br \\ & \left( \text{iii} \right)C{{H}_{3}}C{{H}_{2}}\underset{{}}{\overset{\begin{smallmatrix} \,C{{H}_{3}} \\ |\,\,\,\,\, \end{smallmatrix}}{\mathop{-CH-}}}\,C{{H}_{2}}Br \\ & \left( \text{iv} \right)C{{H}_{3}}\underset{\begin{smallmatrix} | \\ \,\,\,\,C{{H}_{3}} \end{smallmatrix}}{\overset{\begin{smallmatrix} \,\,\,\,\,C{{H}_{3}} \\ | \end{smallmatrix}}{\mathop{-C-}}}\,C{{H}_{2}}Br \\ \end{align}\]

A (i) > (ii) > (iii) > (iv)
B (ii) > (iii) > (iv) > (i)
C (iii) > (i) > (ii) > (iv)
D (iv) > (ii) > (i) > (iii)
Answer :   (i) > (ii) > (iii) > (iv)