Solved Example: Haloalkane and Haloarenes | Chemistry for JEE Main & Advanced PDF Download

 Page 1


JEE Solved Example on Haloalkane and 
Haloarenes 
JEE Mains 
Q. 1 Consider the following halo alkanes: 
1 ????
?? ?? 
2 ????
?? ???? 
3 ????
?? ???? 
4 ????
?? ?? 
The increasing order of reactivity in nucleophilic substitution reaction is 
(A) ?? <?? <?? <?? 
(B) ?? <?? <?? <?? 
(C) ?? <?? <?? <?? 
(D) ?? <?? <?? <?? 
Ans: (B) Good leaving group tendency is the driving force 
?CH
3
I>CH
3
Br>CH
3
Cl>CH
3
 F 
 
Q. 2 Which of the following haloalkane is hydrolyzed by ?? ?? ?? mechanism? 
(A) ????
?? ???? 
(B) ????
?? ????
?? ???? 
(C) ????
?? ????
?? ????
?? ???? 
(D) (????
?? )
?? ?????? 
Ans: (D) Hydrolysis of 3
°
 alkane is preferable by ?? ?? 1 mechanism because of the carbocation 
stability(D) 
 
Q3:  The reaction of t -butyl chloride and sodium exthoxide gives mainly 
(A) t-butyl ethyl ether 
(B) 2, 2-dimethylbutane 
(C) 2-methylprop-1-ene 
(D) Isopropyl n-propyl ether 
Ans: (C) 
 
Page 2


JEE Solved Example on Haloalkane and 
Haloarenes 
JEE Mains 
Q. 1 Consider the following halo alkanes: 
1 ????
?? ?? 
2 ????
?? ???? 
3 ????
?? ???? 
4 ????
?? ?? 
The increasing order of reactivity in nucleophilic substitution reaction is 
(A) ?? <?? <?? <?? 
(B) ?? <?? <?? <?? 
(C) ?? <?? <?? <?? 
(D) ?? <?? <?? <?? 
Ans: (B) Good leaving group tendency is the driving force 
?CH
3
I>CH
3
Br>CH
3
Cl>CH
3
 F 
 
Q. 2 Which of the following haloalkane is hydrolyzed by ?? ?? ?? mechanism? 
(A) ????
?? ???? 
(B) ????
?? ????
?? ???? 
(C) ????
?? ????
?? ????
?? ???? 
(D) (????
?? )
?? ?????? 
Ans: (D) Hydrolysis of 3
°
 alkane is preferable by ?? ?? 1 mechanism because of the carbocation 
stability(D) 
 
Q3:  The reaction of t -butyl chloride and sodium exthoxide gives mainly 
(A) t-butyl ethyl ether 
(B) 2, 2-dimethylbutane 
(C) 2-methylprop-1-ene 
(D) Isopropyl n-propyl ether 
Ans: (C) 
 
Q4 The fire extinguisher 'pyrene' contains. 
(A) Carbon dioxide 
(B) Carbon disulphide 
(C) Carbon Tetrachloride 
(D) Chloroform 
Ans: (C) Pyrene contains CCl
4
 
 
Q. 5 The final product (Z) is the following sequence of reactions 
 
(A) Methanamine 
(B) Ethanamide 
(C) Ethanamine 
(D) Propan-1-amine 
Ans: (C) 
 
Q6 Consider the following reactions: 
1 ????
?? ????
?? ????
?? ???? +?? -
? 
2 (????
?? )
?? ?? -???? + ethanolic ?????? ? 
3 ????
?? ???????????? ?? + aqueous ?????? ? 
4 ????
?? ???????????? ?? + alcoholic ?????? ? 
 
 
Page 3


JEE Solved Example on Haloalkane and 
Haloarenes 
JEE Mains 
Q. 1 Consider the following halo alkanes: 
1 ????
?? ?? 
2 ????
?? ???? 
3 ????
?? ???? 
4 ????
?? ?? 
The increasing order of reactivity in nucleophilic substitution reaction is 
(A) ?? <?? <?? <?? 
(B) ?? <?? <?? <?? 
(C) ?? <?? <?? <?? 
(D) ?? <?? <?? <?? 
Ans: (B) Good leaving group tendency is the driving force 
?CH
3
I>CH
3
Br>CH
3
Cl>CH
3
 F 
 
Q. 2 Which of the following haloalkane is hydrolyzed by ?? ?? ?? mechanism? 
(A) ????
?? ???? 
(B) ????
?? ????
?? ???? 
(C) ????
?? ????
?? ????
?? ???? 
(D) (????
?? )
?? ?????? 
Ans: (D) Hydrolysis of 3
°
 alkane is preferable by ?? ?? 1 mechanism because of the carbocation 
stability(D) 
 
Q3:  The reaction of t -butyl chloride and sodium exthoxide gives mainly 
(A) t-butyl ethyl ether 
(B) 2, 2-dimethylbutane 
(C) 2-methylprop-1-ene 
(D) Isopropyl n-propyl ether 
Ans: (C) 
 
Q4 The fire extinguisher 'pyrene' contains. 
(A) Carbon dioxide 
(B) Carbon disulphide 
(C) Carbon Tetrachloride 
(D) Chloroform 
Ans: (C) Pyrene contains CCl
4
 
 
Q. 5 The final product (Z) is the following sequence of reactions 
 
(A) Methanamine 
(B) Ethanamide 
(C) Ethanamine 
(D) Propan-1-amine 
Ans: (C) 
 
Q6 Consider the following reactions: 
1 ????
?? ????
?? ????
?? ???? +?? -
? 
2 (????
?? )
?? ?? -???? + ethanolic ?????? ? 
3 ????
?? ???????????? ?? + aqueous ?????? ? 
4 ????
?? ???????????? ?? + alcoholic ?????? ? 
 
 
 
Ans:  (B) 1 I
-
is better leaving group so no reaction 
2. E1 
3. ?? ?? 2 
4. E1 
 
Q7:  Aryl halides are less reactive towards nucleophilic substitution reaction as compared to alkyl 
halides due to 
(A) The formation of less stable carbonium ion 
(B) Resonance stabilization 
(C) Longer carbon-halogen bond 
(D) ????
?? -hybridized ?? attached to the ?? 
Ans:  (D) HBr will give step (I) while Br
2
 will give 2Br groups in step (I) only. 1
°
 alkyl halide so S
N
2 
substitution(B) peroxide will cause allyl substitution 
 
 
 
 
Page 4


JEE Solved Example on Haloalkane and 
Haloarenes 
JEE Mains 
Q. 1 Consider the following halo alkanes: 
1 ????
?? ?? 
2 ????
?? ???? 
3 ????
?? ???? 
4 ????
?? ?? 
The increasing order of reactivity in nucleophilic substitution reaction is 
(A) ?? <?? <?? <?? 
(B) ?? <?? <?? <?? 
(C) ?? <?? <?? <?? 
(D) ?? <?? <?? <?? 
Ans: (B) Good leaving group tendency is the driving force 
?CH
3
I>CH
3
Br>CH
3
Cl>CH
3
 F 
 
Q. 2 Which of the following haloalkane is hydrolyzed by ?? ?? ?? mechanism? 
(A) ????
?? ???? 
(B) ????
?? ????
?? ???? 
(C) ????
?? ????
?? ????
?? ???? 
(D) (????
?? )
?? ?????? 
Ans: (D) Hydrolysis of 3
°
 alkane is preferable by ?? ?? 1 mechanism because of the carbocation 
stability(D) 
 
Q3:  The reaction of t -butyl chloride and sodium exthoxide gives mainly 
(A) t-butyl ethyl ether 
(B) 2, 2-dimethylbutane 
(C) 2-methylprop-1-ene 
(D) Isopropyl n-propyl ether 
Ans: (C) 
 
Q4 The fire extinguisher 'pyrene' contains. 
(A) Carbon dioxide 
(B) Carbon disulphide 
(C) Carbon Tetrachloride 
(D) Chloroform 
Ans: (C) Pyrene contains CCl
4
 
 
Q. 5 The final product (Z) is the following sequence of reactions 
 
(A) Methanamine 
(B) Ethanamide 
(C) Ethanamine 
(D) Propan-1-amine 
Ans: (C) 
 
Q6 Consider the following reactions: 
1 ????
?? ????
?? ????
?? ???? +?? -
? 
2 (????
?? )
?? ?? -???? + ethanolic ?????? ? 
3 ????
?? ???????????? ?? + aqueous ?????? ? 
4 ????
?? ???????????? ?? + alcoholic ?????? ? 
 
 
 
Ans:  (B) 1 I
-
is better leaving group so no reaction 
2. E1 
3. ?? ?? 2 
4. E1 
 
Q7:  Aryl halides are less reactive towards nucleophilic substitution reaction as compared to alkyl 
halides due to 
(A) The formation of less stable carbonium ion 
(B) Resonance stabilization 
(C) Longer carbon-halogen bond 
(D) ????
?? -hybridized ?? attached to the ?? 
Ans:  (D) HBr will give step (I) while Br
2
 will give 2Br groups in step (I) only. 1
°
 alkyl halide so S
N
2 
substitution(B) peroxide will cause allyl substitution 
 
 
 
 
Q. 8 In the following reaction: 
 
Ans:  (D) HBr will give step (I) while Br
2
 will give 2Br groups in step (I) only. 1
°
 alkyl halide so S
N
2 
substitution(B) peroxide will cause allyl substitution 
 
Q?? : ???? -????
?? -?? -????
?? ????
?? will undergo rapid 
(A) ?? ?? ?? substitution 
(B) ?? ?? ?? substitution 
(C) Both equal rates (?? ?? ?? and ?? ?? ?? ) 
(D) None of these 
Ans: (B) More electron density than high nucleophilicity. More electron density than high more +| 
effect, high e
-
density. 
 
 
 
 
 
 
Page 5


JEE Solved Example on Haloalkane and 
Haloarenes 
JEE Mains 
Q. 1 Consider the following halo alkanes: 
1 ????
?? ?? 
2 ????
?? ???? 
3 ????
?? ???? 
4 ????
?? ?? 
The increasing order of reactivity in nucleophilic substitution reaction is 
(A) ?? <?? <?? <?? 
(B) ?? <?? <?? <?? 
(C) ?? <?? <?? <?? 
(D) ?? <?? <?? <?? 
Ans: (B) Good leaving group tendency is the driving force 
?CH
3
I>CH
3
Br>CH
3
Cl>CH
3
 F 
 
Q. 2 Which of the following haloalkane is hydrolyzed by ?? ?? ?? mechanism? 
(A) ????
?? ???? 
(B) ????
?? ????
?? ???? 
(C) ????
?? ????
?? ????
?? ???? 
(D) (????
?? )
?? ?????? 
Ans: (D) Hydrolysis of 3
°
 alkane is preferable by ?? ?? 1 mechanism because of the carbocation 
stability(D) 
 
Q3:  The reaction of t -butyl chloride and sodium exthoxide gives mainly 
(A) t-butyl ethyl ether 
(B) 2, 2-dimethylbutane 
(C) 2-methylprop-1-ene 
(D) Isopropyl n-propyl ether 
Ans: (C) 
 
Q4 The fire extinguisher 'pyrene' contains. 
(A) Carbon dioxide 
(B) Carbon disulphide 
(C) Carbon Tetrachloride 
(D) Chloroform 
Ans: (C) Pyrene contains CCl
4
 
 
Q. 5 The final product (Z) is the following sequence of reactions 
 
(A) Methanamine 
(B) Ethanamide 
(C) Ethanamine 
(D) Propan-1-amine 
Ans: (C) 
 
Q6 Consider the following reactions: 
1 ????
?? ????
?? ????
?? ???? +?? -
? 
2 (????
?? )
?? ?? -???? + ethanolic ?????? ? 
3 ????
?? ???????????? ?? + aqueous ?????? ? 
4 ????
?? ???????????? ?? + alcoholic ?????? ? 
 
 
 
Ans:  (B) 1 I
-
is better leaving group so no reaction 
2. E1 
3. ?? ?? 2 
4. E1 
 
Q7:  Aryl halides are less reactive towards nucleophilic substitution reaction as compared to alkyl 
halides due to 
(A) The formation of less stable carbonium ion 
(B) Resonance stabilization 
(C) Longer carbon-halogen bond 
(D) ????
?? -hybridized ?? attached to the ?? 
Ans:  (D) HBr will give step (I) while Br
2
 will give 2Br groups in step (I) only. 1
°
 alkyl halide so S
N
2 
substitution(B) peroxide will cause allyl substitution 
 
 
 
 
Q. 8 In the following reaction: 
 
Ans:  (D) HBr will give step (I) while Br
2
 will give 2Br groups in step (I) only. 1
°
 alkyl halide so S
N
2 
substitution(B) peroxide will cause allyl substitution 
 
Q?? : ???? -????
?? -?? -????
?? ????
?? will undergo rapid 
(A) ?? ?? ?? substitution 
(B) ?? ?? ?? substitution 
(C) Both equal rates (?? ?? ?? and ?? ?? ?? ) 
(D) None of these 
Ans: (B) More electron density than high nucleophilicity. More electron density than high more +| 
effect, high e
-
density. 
 
 
 
 
 
 
Q10:  The correct order of nucleophilicity is 
 
Ans: 
 
Q. 11 Arrange the following in order of decreasing reactivity towards ?? ?? ?? reaction. 
(i) ????
?? ????
?? ????
?? ???? 
(ii) ????
?? ????
?? ???????????? ?? 
(iii) (????
?? )
?? ???????? ?? ???? 
(iv) (????
?? )
?? ?????? 
(A) (i) > (ii) > (iii) > (iv) 
(B) (iii) > (iv) > (ii) > (i) 
(C) (i) > (iii) > (ii) > (iv) 
(D) (iv) > (iii) > (ii) > (i) 
Ans:  (C) For ?? ?? 21
°
>2
°
>3
°
 
Thus order of decreasing reactivity towards ?? ?? 2 reaction is 
CH
3
CH
2
CH
2
Cl>(CH
3
)
2
CHCH
2
Cl
?                      
1
°
>CH
3
CH
2
CHClCH
3
?          
2
°
>(CH
3
)
3
CCl
?      
3
°