wayground logo

Free Printable Worksheets

NEW

Font size

S
M
L
XL
Worksheets

CLASS XII CHEMISTRY (HALOALKANES AND HALOARENES)

Total questions: 20

Worksheet time: 10mins

Name
Class
Date
1.

1. Which alkyl halide has the highest reactivity for a particular alkyl group?

a)

R-F

b)

R-Cl

c)

R-I

d)

R-Br

2.

Write the order of increasing S1N reactivity for the following alkyl halides:

A) CH3-X

B) (CH3)2CH-X

C) (CH3)3C-X

D) (CH3)3C-CH2-X

a)

a) A>C>B>D

b)

b) C>A>B>D

c)

c) C>B>D>A

d)

d) D>C>B>A

3.

Toluene reacts with a halogen in the presence of iron (III) chloride giving ortho and para halo compounds. The reaction is

a)

Electrophilic elimination reaction

b)

Electrophilic substitution reaction

c)

Free radical addition reaction

d)

Nucleophilic substitution reaction

4.

. Which is the correct increasing order of boiling points of the following compounds?

a)

Bromobenzene < 1-Bromobutane < 1-Bromopropane < 1-Bromoethane

b)

Bromobenzene < 1-Bromoethane < 1-Bromopropane < 1-Bromobutane

c)

1-Bromopropane < 1-Bromobutane < 1-Bromoethane < Bromobenzene

d)

1-Bromoethane < 1-Bromopropane < 1-Bromobutane < Bromobenzene

5.

Which reagent will you use for the following reaction?

CH3CH2CH2CH3 → CH3CH2CH2CH2Cl + CH3CH2CHClCH3

a)

Cl2 /UV light

b)

NaCl + H2SO4

c)

Cl2 gas in dark

d)

Cl2 gas in the presence of iron in dark

6.

3. Which of the following is not the method of preparation of alkyl halide?

a)

a) Darzen’s method

b)

b) Halogenation of alkene

c)

c) Addition of HX on alkenes

d)

d) Hydration of alkene

7.

Complete the following reaction
R-OH + PCl5  \rightarrow  RCl + X + HCl
X is

a)

PCl3

b)

PCl5

c)

POCl3

d)

POBr3

8.

complete the following reaction
R-OH + X  \rightarrow  RCl + SO2 + HCl

a)

SO2

b)

SOCl3

c)

SOCl2

d)

SOCl

9.

When excess chlorine is used in electrophilic substitution of toluene, which of the following dichloroarenes are formed?

a)

Ortho and meta

b)

Ortho and para

c)

Meta and para

d)

Ortho, meta and para

10.

Which of the following undergoes nucleophilic substitution exclusively by SN1 mechanism?

a)

Ethyl chloride

b)

Isopropyl chloride

c)

Choro benzene

d)

Benzyl chloride

11.

Assertion: KCN reacts with methyl chloride to give methyl isocyanide.

Reason: CN- is an ambidentate nucleophile.

a)

A

b)

B

c)

C

d)

D

12.

In a SN1 reaction on chiral centres, there is

a)

100% retention

b)

100% inversion

c)

Racemization

d)

None

13.

Ambident nucleophile is

a)

CN

b)

H2O

c)

Cl

d)

NH2

14.

Haloalkane is a polar molecule that undergoes nucleophilic substitution through SN1 and SN2. Arrange the following haloalkanes in order of increasing rate of unimolecular nucleophilic substitution reaction:

I. 2-chloro-2-methylpropane

II. 2-chlorobutane

III. 1-chlorobutane

a)

I< II < III

b)

I< III < II

c)

III< I < II

d)

III< II < I

15.

Which of the following is a chiral molecule?

a)

CH2BrI

b)

CH3CBr2Cl

c)

(CH3)2CHCl

d)

CH3CHBrCH2CH3

16.

Assertion: Halogen acids react with alcohols to form haloalkanes.

Reason: Order of reactivity of halogen acids HCl>HBr>HI

a)

Both assertion and reason are true and the reason is the correct explanation of the assertion.

b)

Both assertion and reason are true but reason is not the correct explanation of the assertion.

c)

Assertion is true but reason is false.

d)

Assertion is false but reason is true.

17.

Assertion: Electron withdrawing groups in aryl halides increases the reactivity towards nucleophilic substitution.

Reason: 2, 4-Dinitrochlorobenzene is more reactive than chlorobenzene.

a)

Both assertion and reason are true and the reason is the correct explanation of the assertion.

b)

Both assertion and reason are true but reason is not the correct explanation of the assertion

c)

Assertion is true but reason is false

d)

Assertion is false but reason is true.

18.

Assertion (A): Phosphorus chlorides (tri and penta) are preferred over thionyl chloride for the preparation of alkyl chlorides from alcohols.

Reason (R): Phosphorus chlorides give pure alkyl halides.

a)

Assertion and Reason both are correct and Reason is the correct explanation of Assertion.

b)

Assertion and Reason both are correct statements but Reason is not the correct explanation of Assertion.

c)

Assertion is correct but Reason is wrong.

d)

Assertion and Reason both are wrong statements

19.

In SN1 the order of reactivity of halide is:

a)

30 > 20 > 10 > methyl

b)

Methyl > 10>20 > 30

c)

30 > 20 > methyl > 10

d)

20 > 10 > methyl > 30

20.

Which is the correct increasing order of boiling points of the following compounds? 1-Iodobutane, 1-Bromobutane, 1-Chlorobutane, Butane

a)

Butane < 1-Chlorobutane < 1-Bromobutane < 1-Iodobutane

b)

1-Iodobutane < 1-Bromobutane < 1-Chlorobutane < Butane

c)

Butane < 1-Iodobutane < 1-Bromobutane < 1-Chlorobutane

d)

Butane < 1-Chlorobutane < 1-Iodobutane < 1-Bromobutane