CHAPTER # 10 Alkyl Halides MCQs
1.
What should be the products
when reactants are alcohol & thionyl chloride in the presence of
pyridine?
a)
RCl+S+HCl b)
RCl+SO2+HCl
c)
RCl+SO2+H2O d)
RCl+S+H2O
2.
Which C-X bon has the
highest bond energy per mole?
a)
C-F b)
C-Cl
c)
C-Br d)
C-I
3.
Which alkyl halides has the
highest reactivity , for a particular
alkyl group?
a)
R-F b)
R-Cl
c)
R-Br d)
R-I
4.
2.8 is the
electronegativity of________
a)
F b) Cl
c)
Br d)
I
5.
Which one is not a
nucleophile?
a) C2H5O─ b)
SCN─
c)
NH3 d) H3C+
6.
The number of molecules
taking part in the rate determining step
is called_________
a)
Order of reaction
b)
Rate or reaction
c)
Molecularity of a reaction
d)
Extent of a reaction
7.
During SN2
mechanism,carbon atom changes it state
of hybridization from___________
a)
sp→sp2 b) sp2→sp3
c)
sp3→sp d)
sp3→sp2
8.
What will be the order of
reaction of a reaction whose rate can be
expressed R = K [A] [B]?
a)
Zero b)
One
c)
Two d)
Three
9.
Which one among the
following is not a good
leaving group?
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a) HSO4─
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b) Cl─
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c) OH─
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d) Br─
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10.
What is the order of
kinetics in the SN1 mechanism?
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a) Zero
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b) First
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c) Second
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d) Third
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11.
Which alkyl halide out of
the following may follow both SN1 and
SN2 mechanism?
a.
CH3─X
CH3 H
| |
b.
CH3─ C
─ C ─X
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CH3 H
CH3
c.
CH
─ X
CH
─ X
CH3
CH3
|
d.
CH3─ C─ X
|
CH3
12.
In elimination reaction of
alkyl halide, which site is more
susceptible for the attack of
nucleophile?
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a) α-carbon
|
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b) β-carbon
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c) α-hydrogen
|
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d) β-hydrogen
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13.
When two moles of ethyl
chloride react with moles of sodium in
the presence of ether, what will be
formed?
a)
2 moles of ethane b) 1 mole of ethane
c) 2
moles of butane d) 1 mole of butane
14.
Zn-Cu couple and alcohol
generate_______
a)
[H] b)
H2
c)
[O] d)
O2
15.
When CO2 is made
to react with ethyl magnesium iodide,
followed by acid hydrolysis, the product
formed is_________
a)
Propane b) Propanoic acid
c)
Propanal d)
Propanol
16.
Grignard reagent is
reactive due to ________
a.
The presence of halogen
atom
b.
The presence of magnesium
atom
c.
The polarity of C-Mg bond
d.
All
17.
SN2 reaction can be best
carried out with____
a.
Primary alkyl halide
b.
Secondary alkyl halide
c.
Tertiary alkyl halide
d.
All
18.
Elimination bimolecular
reactions involve____
a.
First order kinetics
b.
Second order kinetics
c.
Third order kinetics
d.
Zero order kinetics
19.
For which mechanisms, the
first step involved is the same?
a)
E1+E2 b) E2+SN2
c)
S1+SN1 d)
SN1+SN2
20.
The rate of E1 reaction
depends upon____________
a.
The concentration of
substrate
b.
The concentration of
nucleophile
c.
The concentration of
substrate as well as nucleophile
d.
No dependence
21.
Alkyl halides are
considered to be very reactive compounds
towards nucleophile
because___________
a.
They have an electrophilic
carbon
b.
They have an electrophilic
carbon & a good leaving group
c.
They have an electrophilic
carbon & a bad leaving group
d.
They have a nucleophilic
carbon & a good leaving group
22.
Which one of the following
species in not an electrophile?
a)
NH3 b)
Br+
c) H+
d)
BF3
23. Which one of the following reactants will be required to form ethane from ethyl chloride?
a)
Alcoholic KOH b) Aqueous KOH
c)
Alkaline KMnO4 d)
Aqueous NaOH
24. Which one of the following alcohols will be formed when ethyl magnesium bromide
reacts with acetone?
|
a) Primary alcohol
|
b) Secondary
alcohol
|
|
c) Tertiary alcohol
|
d) Dihydric alcohol
|
25. Which one of the following molecules does not form alcohol when reacts with Grignard reagent?
|
a) Formaldehyde
|
b)
Acetaldehyde
|
|
c) Propanone
|
d) CO2
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26. In primary alkyl halides, the halogen atom is attached to a carbon which is further
attached to how many carbons atoms
a)Two b)
Three
c)
One d)
Four
27. The reactivity order of alkyl halides for a particular alkyl group is.
(A)
Flouride > chloride >
Bromide > Iodide
(B)
Chloride > Bromide >
Flouride > Iodide
(C)
Iodide > Bromide >
Chloride > Flouride
(D)
Bromide > Iodide >
Chloride > Flouride
28. When CO2 is made to react with ethyl magnesium iodide, followed by acid
hydrogen, the product formed is.
(A)
Propane (B) Propanoic acid
(C) Propanal (D) Propanol
29. Grignard reagent is reactive to.
(A)
The presence of halogen
atom
(B)
The presence of Mg atom
(C)
The polarity of C-Mg atom
(D)
None of the above
30. SN2
reactions can be lest carried out with
(A)
Primary alkyl halides
(B)
Secondary alkyl halides
(C)
Tertiary alkyl halides
(D)
All of these
31. Elimination
bimolecular reactions involve.
(A)
First order kinetics
(B)
Second order kinetics
(C)
Third order kinetics
(D)
Zero order kinetics
32. For
which mechanism the 1st step involved in
the same.
(A) El and E2 (B) E2 and SN2
(C) El and E2 (D) El and SN1
33. Alkyl
halides are considered to be very
reactive compounds towards nucleophilies
because.
(A) They have an electrophilic carbon (B) They have an
electrophilic carbon and a good leaving group
(C) They have an electrophilic carbon and a bad leaving group
(D) They have a nucleophilic carbon and a
good leaving group
34. The
rate of E, reaction depends upon
(A)
The concentration of
substrate.
(B)
The concentration of
nucleophile
(C)
The concentration of
substratc as well as uncleophile
(D)
None of the above
35.
Which one of the following is not a nucleophile
(A) H2O (B) H2S
(C) BF3 (D) NH3
36) Which
Monohaloalkane can not be obtained by the direct action of halogen and alkane?
a) RCl
b) RBr
c) RI
d) None of these
37) For the preparation of RX, by the reaction of
Alcohol and Thionyl Chloride requires the presence of a solvent
a) Ether
b) Water
c) Pyridine
d) Acetone
38)
The reaction of Sodium
metal with alkyl halide in the presence of Ether is called
a)
Wurtz’s reaction b) Sabatier reaction
c) Frankland’s reaction d) None of these
39)
Carbon carrying negative
charge is known as
a)
Carbonium ion b) Carbon ion
c)
Oxonium ion d) Oxide ion
40)
Formation of alkane by the
action of Zinc on alkyl halide is called
a)
Wurtz’s reaction b) Sabatier
reaction
c) Frankland’s reaction d) Kolbe’s reaction
41)
Which of the following is
an electrophile?
a)
O
H b)
NH3
c)
ROH d)
BF3
42)
Alkyl halides give
reactions
a) Electrophilic substitution
b) Nucleophilic substitution
c) Electrophilic addition
d) Nucleophilic addition
43)
When Ammonia reacts with
excess of alkyl halides gives
a)
Primary amine b) Secondary amine
c)
Tertiary amine d) Mixture of
amines
44)
Nucleophilic substitution
reactions are represented by
a) E1
b)
SN
c)
ROH d)
RCHO
45)
SN reactions are classified
into types
a) 4 b)
3
c) 2 d)
1
46)
SN2 reactions occur in
a) Primary alkyl halide
b) Secondary alkyl halide
c) Tertiary alkyl halide
d) All of these
47)
Which SN reaction occurs in
two steps?
a)
SN1 b)
SN2
c)
Both d)
None of these
48)
In SN2 reactions, two
reactants are involved in the rate determining step while these reactions occur
in
a)
Two steps b)
Three steps
c)
One step d)
Four steps
49)
Which one of them is
organometallic compound?
a)
RMgX b)
RX
c)
ROH d)
RCHO
50)
When Grignard reagent
reacts with formaldehyde to yield
a)
CH3OH b)
C2H5OH
c)
CH3COCH3 d)
C3H8
51)
The chemical reaction in
which HX is removed from two adjacent carbon atoms of an organic molecule is
called
a) Dehydrogenation
b) Dehydrohalogenation
c) Dehydration
d) Dehalogenation
52)
Reaction of RX with Ammonia
is called
a) Wurtz’s reaction
b) Frankland’s reaction
c) Hoffmann’s reaction
d) Friedal Craft reaction
53)
A nucleophile is a
a)
Lewis acid b)
Lewis base
c)
Arrhenius acid d) Arrhenius base
54)
An electrophile is a
a)
Lewis acid b)
Lewis base
c)
Arrhenius acid d) Arrhenius base
55)
Rate determining steps in
SN1 reaction is always the
a)
Slow step b)
Fast step
c)
Intermediate d) None of these
56)
Which one of the organic
compound is without oxygen?
a)
Ether b)
Ester
c)
Alkyl halides d) Carboxylic acid
57)
Methyl iodide reacts with
silver acetate to yield
a)
Methyl acetate b) Methyl ester
c)
Methylol phenol d) Acetyl halide
58)
Grignard reagent reacts
with formaldehyde to form
a)
Primary alcohol b) Tertiary
alcohol
c)
Acetic acid d)
Ketone
59)
Both methane ethane may be
prepared in one step reaction from
a) C2H4 b)
CH3l
c)
CH3OH d)
C2H5OH
60)
RMgX reacts with PCl3
giving
a)
Methyl phosphate b)Trimethyl
phosphate
c) Dimethyl phosphate d) None of
these
61)
Ethyl iodide on its
interaction with silver nitrate to yield
a)
Ethyl nitrate b) Ethyl nitrite
c)
Nitro methane d) None of these
62)
Elimination reactions are
the reverse of
a) Electrophilic substitution reaction
b) Nucleophilic substitution reaction
c) Addition reaction
d) Oxidation reaction
63)
In electron pair donor is a
strong base
(OH,OR) then the dominant
reactions will be
a) SN2 and E2 is a side reaction
b) E2 and SN2 is side reaction
c) E1 and SN2 is side reaction
d) All of these
64)
E1 reactions occur in
a)
RCH2X b)
R2CHX
c) R3CX
d)
All of these
65)
The removal of hydrogen
from that beta carbon which has fewer H – atoms is called
a)
Wurtz’s rule b) Markownikoff’s rule
c)
Saytzeef’s rule d) Hoffmann’s
rule
66)
Which of them is
organometallic compound?
a)
RMgX b)
TEL
c)
TML d)
All of these
67)
Formula of Thionyl chloride
is _______
a)
SOCl2 b)
ZnCl2
c)
CH3Cl d)
None
68)
When metallic sodium in
ether is heated with
an
alkyl halide, a higher alkane is formed. It is
called
______
a)
Sulphonation b) Wurtz’s
reaction
c)
Friedel-Crafts reacton d) None
69)
Which molecule has a zero
dipole moment?
a)
CH3Cl b)
CCl4
c)
CH2Cl2 d)
CHCl3
70)
Grignard’s reagent reacts
with alkyl halide to
form
________
a)
Alkanes b)
Alkynes
c)
Alkenes d)
Alcohols
71)
On passing CO2
through Grignard reagent ______ is
formed.
a)
Methanoic acid b) Ethanoic acid
c)
Alkyl sodium halide d) None of these
72)
The hydrolysis of alkyl
halides by heating with aqueous alkali is a _______
substitution reaction.
a)
Electrophilic b) Nucleophilic
c)
Both a & b d) None
73)
Ethyl bromide can be
converted into ethyl
alcohol
by heating with,
a)
Aqueous KOH b) Ethanoic KOH
c)
Moist silver oxide d) Both a & c
74)
The major product obtained
by treating 2 – chlorobutane with alcoholic KOH is
a)
1 – Butyne b)
2 – Butyne
c)
1 – Butene d)
2 – Butene
75)
Which of the following is a
vic – dihalide?
a)
ClCH2CH2Cl
b) CH3CHCl2
c)
BrCH2CH2CH2Br d) BrCH2CH2CH2CH2Br
76)
3 – Bromohexane can be
converted into hexane using
a)
Zn, H+ b)
Cu I
c)
(CH3)2CuLi d)
Na
77)
SN2 reaction proceeds via
the formation of
a)
Carbonation b) Transition sate
c)
Free radical d) Carbanion
78)
Which of the following
alkyl halide reacts fastest with AgNO3?
a)
(CH3)3C – Cl b) (CH3)2 CH
Cl
c)
CH3CH2CH2Cl d)
(CH3)2CCH2-Cl
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