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INDIAN SCHOOL MUSCAT
DEPARTMENT OF CHEMISTRY
CLASS XII - CHEMISTRY WORK SHEET -2
HALOALKANES AND HALOARENES
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Give the IUPAC name of the following:
a) (CH3)3CCH2CH(Br)C6H5
d) CHF2CBrClF
b) CH3C(C2H5)2CH2Br
e) (CH3)3CCH=CIC6H4I-p
c) CH3CH=C(Cl)CH2CH(CH3)2
Give reasons:
a. Alkyl halides have higher boiling points than corresponding hydrocarbons.
b. Benzylic and allylic halides follow SN1 mechanism.
c. H3PO4 is used with KI for iodination of alcohols.
d. Halogens are deactivating but ‘o, p’ directive.
e. Presence of electron withdrawing groups on benzene ring increases tendency of
SN reaction.
f. Haloalkanes are more reactive than haloarenes towards nucleophilic substitution
reactions.
Arrange in increasing order of property mentioned giving reasons:
a. Dichlorobenzenes ( melting point)
b. Ethanol and ethylchloride ( solubility in water)
c. 2-Bromo-2-methylbutane, 1-bromopentane, 2-bromopentane(reactivity towards
SN2)
Write short notes on: (a) Sandmeyer reaction (b) Finkelstein reaction (c) Swart’s reaction
(d) Wurtz reaction.
Compare and illustrate SN1 and SN2 mechanisms in alkyl halides.
Write any two uses of :
a) CH2Cl2
b) CHCl3 c) CHI3
d) CCl4
e) Freon
f) DDT
What happens when:
a. CHCl3 is exposed to air
b. Chlorobenzene is treated with Mg in ether and then reacted with water
c. Methyl bromide is treated with metallic sodium in ether
d. Ethyl chloride is treated with aq.KOH.
Bring about the following conversions:
f. 1-bromopropane to 2-bromopropane
a. Benzene to 4-bromonitrobenzene
g. 2-bromopropane to 1-bromopropane
b. Benzylalcohol to 2-phenylethanoic
h. Benzene to diphenyl
acid
i. Tert- butylbromide to
c. Toluene to benzylalcohol
isobutylbromide
d. Propene to 1-propanol
j. Ethanol to ethyl fluoride
e. 1-Butene to 2-butene
k. Chlorobenzene to toluene
How will you distinguish between
a) CH3Cl and CH3Br
b) bromobenzene and benzylbromide
c) vinylchloride and ethylchloride.
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Explain why?
a) Dipole moment of chlorobenzene is lower than that of cyclohexylchloride.
b) Alkyl halides,though polar are immiscible with water.
c) p-Dichlorobenzene has higher melting point and lower solubility than those of
o and m-isomers.
Write the mechanism of the following reaction:
𝐸𝑡𝑂𝐻 −𝐻2𝑂
12.
n- BuBr + KCN
n- Bu-CN + KBr
An optically active compound having molecular formula C7H15Br reacts with aq. KOH
to give a racemic mixture of products. Write the mechanism involved for the reaction.
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