Question bank chem 1st year

Halogen Derivative

HALOGEN DERIVATIVE
EXERCISE # II (A)
(Choose the correct option. One or more than one are correct)
1. Rate of SN2 depends on :
(A) Conc of Nucleophile (B) Conc of substrate
(C) Nature of leaving group (D) Nature of solvent
2. SN2 reaction will be negligible in
Br

(A) (B) (C) (D)

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3. Br–CH–CH=CH2 ¾¾
HI
®
CH3
Products which can be obtained during the reaction in good yield :
14 14
(A) Br–CH–—CH–I (B) I–CH––—CH–Br
CH3 CH3 CH3 CH3
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(C) Br–CH–CH2–CH2–I (D) I–CH–CH2–CH2–Br
CH3 CH3
4. In the given pair in which pair the first compound is more reactive than second towards S N2 reaction.
Cl
(A) Cl CH2Cl (B)
Cl

Cl Cl

(C) (D)
Cl Cl
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5. Consider the given reaction
CH 3
|
H - C - OTs ¾¾¾
NaCN
(DMF)
® CH3CH 2CH - CN
| |
C H (S)
2 5
CH 3


which of following statements is/are correct for the above reaction.
(A) Product formation takes place due to the breaking of O–Ts
(B) The reaction is SN2
(C) The reaction is SN1
(D) Configuration of product is (R)
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6. Which of the following statements is / are true?
(A) CH3–CH2–CH2–I will react more readily than (CH3)2 CHI for SN2 reactions.
(B) CH3–CH2–CH2–Cl will react more readily than CH3–CH2–CH2–Br for SN2 reaction.
(C) CH3–CH2–CH2–CH2–Br will react more readily than (CH3)3C–CH2–Br for SN2 reactions
(D) CH3–O–C6H4– CH2Br will react more readily than NO2–C6H5–CH2Br for SN2 reaction
7. Incorrect statement about alkyl halides is / are:
(A) Tertiary alkyl halides undergo SN2 substitutions
(B) Alkyl iodides on exposure to sunlight gradually darken
(C) Photo iodination is irreversible in presence of HIO3
(D) A nucleophilic substitution is most difficult in alkyl iodides
8. Which of following reaction(s) produce Saytzeff product as a major product :
Cl
–
NH2 alc. KOH /
(A) (B)
F
+
Me3CO– K –
OR
(C) (D)
Cl NMe3
+
9. SN1 & SN2 is not favourable in
(A) H2C = CH–Cl (B) Ph–CH2–Cl (C) Ph–Cl (D) H2C=CH–CH2–Cl
10. Consider the given reaction :
CH3–CH=CH–CH2–OH ¾¾
HBr
¾
SN 1'
® [P]

In the given reaction the product [P] can be :
Br
|
(A) CH3–CH=CH–CH2–Br (B) CH3 - CH - CH = CH 2
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Br
|
(C) CH2=CH–CH=CH2 (D) CH 3 - CH - CH 2 - CH 2 - OH
11. Correct statement(s) for the product(s) of following reaction.
CH2 = CH – CH2 – Ph ¾Cl
¾¾ ¾®
/ 500°C
2

(A) Four different products are formed
(B) Two optically active products are formed
(C) The optically active compound formed here can also be made by the reaction of HCl
(D) The reaction path is free radical substitution.


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, Halogen Derivative
12. In which of the following reaction configuration about chiral C is retained in the final product

CH Br SOCl CH ONa
(A) Na
¾¾® ¾¾3¾® (B) ¾¾¾2 ® ¾¾3¾¾®



H + / MeOH
(C) PCl
¾¾¾3 ® ¾¾3¾¾®
CH ONa
(D) ¾¾ ¾ ¾
¾®


13. A gem dichloride is formed in the reaction :
(A) CH3CHO and PCl5 (B) CH3COCH3 and PCl5
(C) CH2 = CH2 and Cl2 (D) CH2 = CHCl and HCl
14. In which product formation takes place according to Hoffmann's rule
1Å 1Å
(A) CH 3CH 2 - CH - CH 3 ¾¾¾¾
t - Bu OK
® (B) CH3CH 2 - CH - CH 3 ¾¾¾¾
CH 3CH 2 O K
¾®
| D | D
Br Br

1 1

¾¾® (D) CH3CH2CH - CH 3 ¾¾®
OH OH
(C)
D
Å
| D

S(CH3 ) 2
15. Which of following are correct for given reaction

D
¾¾®


H3C
(A) Major product of reaction is (B) Major product is
N


(C) The reaction is thermal elimination reaction (D) The reaction is E2 reaction
16. In which case incorrect products are formed :
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(A) Me3C–O–CH3 HI Me3C–OH + CH3I

(B) H3C–O–CH2–CH3 HI CH3OH + ICH2CH3

HI
(C) O – CH2 I + CH2–OH


OH
(D) Anisole HI + CH3I



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