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HALOALKAES AND HALOARENES

CHARACTERISTICS OF HALOGEN COMPOUNDS

Question 1

Write the IUPAC name of the following compound:(CH3)3CCH2BrAns.

The IUPAC name of the given structure is 2, 2-Dimethylbromopropane.

Question 2

Ans.

Question 3Give the common name o the o!!o"in#.$i% &' ()omo*)o*ane$ii% +'ch!o)o *)o*ane$iii% &'ch!o)o'+'meth,!*)o*aneAns.

(i) Common name of 1- Bromopropane is n-propylbromide(ii) Common name of 2-chloro propane is Isopropyl chloride(iii) Common name of 1-chloro-2-methylpropane Isobutyl chloride

Question 4C!assi, the o!!o"in# as a!-,! a!!,! /en0,! vin,! o) a),! ha!i1es2

$i% $CH3%+CHCH$C!%CH3$ii% $ CH3%3CCH+CH$()%C4H5

$iii% CH3CH6C$C!%CH+CH$CH3%+ $iv% CH3CH6CHC$()%$CH3%+

$v% p'C!C4H7CH+CH$CH3%+Ans.

(i) Alyl halide! (C"3)2C"C" (Cl) C"3(ii) Allyl halide! C"3C"#C"C (Br) (C"3)2(iii) Ben$yl halide! (C"3)3CC"2C" (Br) C%"&(i') inyl halide! C"3C"#C (Cl) C"2C" (C"3)2(') Aryl halide!p-ClC%"4C"2C" (C"3)2

Question &8)ite the isome)s o the com*o9n1 havin# o)m9!a C7H:().Ans.

i C"3C"2C"2C"2Br

ii C"3C"2C" (Br)C"3iii C"3C"(C"3) C"2Bri' C"3CBr(C"3) C"3

Question %Deine )acemisation;Ans.

A mi*ture containin+ t,o enantiomers in eual proportions is no,n as )acemic mi

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/he compounds in ,hich the halo+en atom is bonded to an sp3-hybridised carbon atom ne*t to an aromatic rin+ is called ben$ylic halide

Question 8hat is the common name o & 3'Di/)omo/en0ene;Ans.

m'5ibromoben$ene

Question 168hat is the #ene)a! o)m9!a o) a!-,! ha!i1e;Ans.

Cn"2n 7 189 ,here 8 is halo+en atom and n is the number of carbon atom

Question 118)ite the st)9ct9)es o the o!!o"in# o)#anic ha!o#en com*o9n1.

+'Ch!o)o'3'meth,!*entane.Ans.

C"3C" (Cl) C" (C"3) C"2C"3

Question 12Give the IUPAC name o the com*o9n1 CH3CH $C!% CH $()% CH3.Ans.

2-bromo-3-chloro-Butane

:eneral methods of preparationQuestion 18)ite the st)9ct9)e o the ma=o) o)#anic *)o19ct in each o the o!!o"in# )eactions2

$i% CH3CH+CH+OH > SOC!+

$ii% CH3CH+CH 6 CH+> H()

$iii% CH3CH 6 C $CH3%+> H()Ans.

(i) C"3C"2C"2Cl(ii) C"3C"2C"2C"2Br(iii) C"3C"2CBr(C"3)2

Question 28)ite the e?9ations o) the *)e*a)ation o &'io1o/9tane )om

$i% &'/9tano!$ii% &'ch!o)o/9tane$iii% (9t'&'ene.

Ans.

(i) C"3C"2C"2C"2;" C"3C"2C"2C"2I 1-butanol 1-iodobutane

(ii) C"3C"2C"2C"2Cl 7 NaIAns.

$i%

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7 =;2 7"Cl(ii)

(iii) C"3C"2Br 7

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iii!The /0 substitution reaction involves the formation of carbocation, %hich is not affecte$ by the presence of bul#y groups.Thus, C1"C"C1"!3r %ill be more reactive to%ar$s /0 substitution reaction forming racemic mi&ture.

Question 2

A olution of 0H h"drol"e CH3CHClCH2CH3and CH2CH2CH2CH2ClWhich one of thee i more eail" h"drol"ed%Ans.

un$ergoes hy$rolysis more easily than .

being a primary al#yl hali$e has less steric hin$rance than %hich is secon$ary al#yl hali$e.

Question 3

Ans.

Question 4Give )easons o) the o!!o"in#2$i% G)i#na)1 )ea#ent sho9!1 /e *)e*a)e1 9n1e) anh,1)o9s con1itions.$ii% Neo'*ent,! /)omi1e 9n1e)#oes n9c!eo*hi!ic s9/stit9tin# )eactions ve), s!o"!,.$iii% *'Metho

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Question %Give )easons o) the o!!o"in#2

i% Ha!oa!-anes )eact "ith KCN to o)m a!-,! c,ani1es as main *)o19ct "hi!e A#CN o)ms isoc,ani1e as the chie *)o19cts. ii% A!coho!s 1o not )eact "ith Na() /9t "hen H+SO7is a11e1 the, o)m a!-,! /)omi1es.Ans.

i) ?C< is predominantly ionic and pro'ides cyanide ions in solution Althou+h both carbon and nitro+en atoms of C< can donate electron pairs but the attac

taes place mainly throu+h carbon atom and not throu+h nitro+en atom because C-C bond is more stable than C-< bond "o,e'er A+C< is mainly co'alentin nature and nitro+en is free to donate electron pair formin+ isocyanide as the main productii) Br-is a ,ea base =o it cannot displace the stron+ base ;" -,hen "2=;4is added9 it leads to protonation of alcohol9 as a result of ,hich ,ater molecule isformed =ince ,ater molecule is a 'ery ,ea base it is easily replaced by Br-

Question .8hat is Sa,t0e )9!e; I!!9st)ate "ith s9ita/!e e

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8hich com*o9n1 in each o the o!!o"in# *ai)s "i!! )eact aste) in SN+ )eaction "ith 'OH;$i% CH3() o) CH3I $ii% $CH3%3CC! o) CH3C!Ans.(i) C"3I ,ill react faster than C"3Br because the order of reacti'ity is as follo,s

-I -Br -Cl -0(ii) C"3Cl ,ill react faster than (C"3)3CCl because the order of reacti'ity is as follo,s in =

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Chloroform is o*idi$ed slo,ly by air in the presence of li+ht to an e*tremely poisonous +as9 carbonyl chloride9 also no,n as Ghos+ene

"ence it is ept closed in dar colored bottles

Question %Give the )o!e o ca)/on tet)ach!o)i1e an1 F)eon on envi)onmenta! 1e#)a1ation.Ans.

Both the carbon tetrachloride and 0reon causes depletion of o$one layer ,hen released in air because they remain unchan+ed and diffuses into stratosphere/he depletion of o$one layer increases the e*posure of rays to human bein+ ,hich results in sin cancer9 eye disorder and immune system diseases

Question .8h, the 9se o ch!o)oo)m as anesthetic is 1ec)easin#;Ans.

Inhalin+ chloroform 'apors depresses the central ner'ous system and its chronic e*posure may cause dama+e to the li'er and idneys due to metabolism ofchloroform to phos+ene +as "ence the use of chloroform as anesthetic is decreasin+

Question Give t"o ha0a)1o9s eects o meth,!ene 1ich!o)i1e.Ans.

i) It harms the central ner'ous system(ii) ;n direct contact ,ith sin causes se'ere burnin+

Question 8hat is io1oo)m; Give one 9se o it.Ans./riodomethane is called iodoform and can be used as antiseptic due to liberation of free iodine

Question 168hat a)e )eons; Give one e*ample CCl202

Question 11Give the 9!! name o DDT.Ans.

p,p-5ichlorodiphenyltrichloroethane