CLASS XII Halo Alkane- Haloarene

CLASS XII -4 UNIT-10 -HALOALKANE AND HALOARENES (04 MARKS )-1 1. Classificati! f "alal#a!$s a!% "al a&$!$s '.N$!clat&$ f "alal#a!$s a!% "ala&$!$s *. Nat& Nat&$$ f C-X +!% +!% 4. ,&$a& ,&$a&at ati i!! f "alal "alal#a #a!$ !$ss .," .,"/s /sic ical al &$& &$&ti$ ti$ss f "alal "alal#a #a!$ !$ss . Ncl$"ilic s+stitti! &$acti!s f "alal#a!$s .c"$ical &$acti!s f "alal#a!$s .&$a&ati! f "ala&$!$s . ,"/sical &$&ti$s f "ala&$!$s "ala&$!$s .c"$ical &$&ti$s f "ala&$!$s 2.l/"al3$! 2.l/"al3$! c!%s 1. Classificati! 

(a) Al#/l "ali%$  ( "al3$! attac"$% t s *- C )

(+) All/lic "ali%$  ( "al3$! attac"$% t s *-C !$5t t C6C )

(c) 7$!8/lic "ali%$ ( "al3$! attac"$% t s*-C !$5t t a! a&atic a&atic &i!3 )

(%) 9i!/lic "ali%$ ( "al3$! attac"$% t s '-C f a C6C +!% )

Subhasish sir

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($)A&/l "ali%$ ( "al3$! attac"$% t s '-C f +$!8$!$ +$!8$!$ &i!3 )

'.N$!clat&$ 

3. NATURE OF CRBON HALOGEN BOND :

Subhasish sir

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($)A&/l "ali%$ ( "al3$! attac"$% t s '-C f +$!8$!$ +$!8$!$ &i!3 )

'.N$!clat&$ 

3. NATURE OF CRBON HALOGEN BOND :

Subhasish sir

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T"$ &%ct f $X% f& c"l&i%$s is 3&$at$& t"a! fl&i%$s as t"$ % f C-Cl is c" 3&$at$& t"a! % f C-:.

4. PREPARATION OF HALOALKANES : (a)7/ t"$ acti! f "al3$! aci%s  R$acti! f Alc"ls ;it" H/%&3$! Hali%$s Subhasish sir

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Reaction tye: N!c"eo#i"ic S!$%tit!tion &S N' o( SN)* •

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' > 1 > $t"/l. H/%&3$! "ali%$ &$acti=it/ &%$&  HI > H7& > HCl > H: (a&all$li!3 aci%it/ &%$&). R$acti! sall/ &c$$%s =ia a!  SN1 $c"a!is ;"ic" &c$$%s =ia a ca&+cati! i!t$&$%iat$? t"at ca! als !%$&3 &$a&&a!3$$!t. M$t"a!l a!% &ia&/ alc"ls ;ill &c$$% =ia a! SN' $c"a!is si!c$ t"$s$ "a=$ "i3"l/ !fa=&a+l$ ca&+cati!s. T"$ &$acti! f alc"ls ;it" HCl i! t"$ &$s$!c$ f @!Cl ' (catal/st) f&s t"$ +asis f t"$ Lcas t$st f& alc"ls. SN' +ECHANIS+ FOR REACTION OF ALCOHOLS ,ITH HB( Ste ': A! aci%+as$ &$acti!. ,&t!ati! f t"$ alc"lic 5/3$! t a#$ a +$tt$& l$a=i!3 3&. T"is st$ is =$&/ fast a!% &$=$&si+l$. T"$ l!$ ai&s ! t"$ 5/3$! a#$ it a L$;is +as$.

Ste ): Cl$a=a3$ f t"$ C-O +!% all;s t"$ lss f t"$ 3% l$a=i!3 3&)- ? a !$t&al ;at$& l$cl$? t 3i=$ a ca&+cati! i!t$&$%iat$. T"is is t"$ &at$ %$t$&i!i!3 st$ (+!% +&$a#i!3 is $!%t"$&ic)

Ste 3: Attac# f t"$ !cl$"ilic +&i%$ i! ! t"$ $l$ct&"ilic ca&+cati! c&$at$s t"$ al#/l +&i%$.

(+) B&=$s &c$ss Subhasish sir

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HCl &$i&$s a L$;is aci% catal/st a&ticla&l/ ;it" &ia&/ a!% s$c!%a&/ alc"ls. H7& a!% HI ca! &$act ;it"t si!3 a!/ catal/st. E.3. C!=$&si! f $t"/l alc"l? a &ia&/ alc"l t $t"/l c"l&i%$ &$i&$s @!Cl '? a L$;is aci%.

 A c+i!ati! f %&/ HCl 3as a!% a!"/%&s @!Cl ' als #!;! as FLcas &$a3$!tF is $l/$% t 3$t al#/l c"l&i%$s. It is s$% t %iff$&$!tiat$ +$t;$$! &ia&/? s$c!%a&/ a!% t$&tia&/ alc"ls.  T"$ &$acti=it/ f =a&is alc"ls fll;s t"$ &%$& $t"/l G &ia&/ G s$c!%a&/ G t$&tia&/. I!%$$%? t$&tia&/ alc"ls &$act ;it" HCl $=$! i! a+s$!c$ f a catal/st. E.3. t$&t-+t/l c"l&i%$ ca! +$ s/!t"$si8$% +/ assi!3 HCl 3as i!t a! a$s slti! f t$&t-+t/l alc"l at l; t$$&at&$s.

Reacti-ity it# L!ca% (ea/ent T&+i%it/ a$a&s aft$& 10 i!t$s. S$ ti$s t"$ P(i0a(y &'o* &$acti! a/ ta#$ s$=$&al %a/s. I! cl% c!%iti!s? t&+i%it/ Secon1a(y &)o* a$a&s i! 1- i!t$s. T&+i%it/ a$a&s i$%iat$l/ Te(tia(y &3o* i! cl% c!%iti!s. Note: A$a&a!c$ f t&+i%it/ is t"$ i!%icati! f f&ati! f al#/l "ali%$. T&+i%it/ a$a&s si!c$ al#/l "ali%$s a&$ l$ss isci+l$ ;it" alc"ls. T"$/ a&$ f&$% as sall %&l$ts as i! a ss$!si!. A"co#o"

(c) &$a&ati! f +&al#a!$s Rat"$& t"a! si!3 "/%&+&ic aci%? / sall/ t&$at t"$ alc"l ;it" a i5t&$ f s%i & tassi +&i%$ a!% c!c$!t&at$% sl"&ic aci%. T"is &%c$s "/%&3$! +&i%$ ;"ic" &$acts ;it" t"$ alc"l. T"$ i5t&$ is ;a&$% t %istil ff t"$ +&al#a!$.  ;ill fi!% &actical %$tails f a &$acti! f t"is #i!% f&t"$& %;! t"$ a3$.

Subhasish sir

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&e*+a2in/ #a"o/enoa"2ane% (o0 a"co#o"% !%in/ #o%#o(!% #a"i1e% +a2in/ c#"o(oa"2ane%  C"l&al#a!$s ca! +$ a%$ +/ &$acti!3 a! alc"l ;it" lii% "s"&s(III) c"l&i%$? ,Cl *.

Note: T"$ &$as! f& c"si!3 a sli3"tl/ +i33$& alc"l as a! $5al$ &at"$& t"a! si!3 $t"a!l is t"at c"l&$t"a!$ (;"ic" ;l% +$ f&$% ;it" $t"a!l) is a 3as? a!% t"$ &$a&ati! ;l% "a=$ t +$ "a!%l$% %iff$&$!tl/. 1-c"l&&a!$ (f&$% i! t"is $ati!) is a lii%.

(%),&$a&ati! f i%al#a!$s  I! t"is cas$ t"$ alc"l is &$act$% ;it" a i5t&$ f s%i & tassi i%i%$ a!% c!c$!t&at$% "s"&ic(9) aci%? H *,O4? a!% t"$ i%al#a!$ is %istill$% ff. T"$ i5t&$ f t"$ i%i%$ a!% "s"&ic(9) aci% &%c$s "/%&3$! i%i%$ ;"ic" &$acts ;it" t"$ alc"l. ,"s"&ic(9) aci% is s$% i!st$a% f c!c$!t&at$% sl"&ic aci% +$cas$ sl"&ic aci% 5i%is$s i%i%$ i!s t i%i!$ a!% &%c$s "a&%l/ a!/ "/%&3$! i%i%$. A siila& t"i!3 "a$!s t s$ $5t$!t ;it" +&i%$ i!s i! t"$ &$a&ati! f +&al#a!$s? +t !t $!3" t 3$t i! t"$ ;a/ f t"$ ai! &$acti!.  (f)R$acti! f Alc"ls ;it" t"$& Hal3$!ati!3 a3$!ts (SOCl '? ,X*?,X)

Reaction tye: N!c"eo#i"ic S!$%tit!tion &S N' o( SN)* •

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Alc"ls ca! als +$ c!=$&t$% t al#/l c"l&i%$s si!3 t"i!/l c"l&i%$? SOCl '? & "s"&s t&ic"l&i%$? ,Cl*. Al#/l +&i%$s ca! +$ &$a&$% i! a siila& &$acti! si!3 ,7& *. Us$% stl/ f& 1  a!% ' ROH I! $ac" cas$ a +as$ is s$% t F-F t"$ aci%ic +/-&%ct. C! +as$s a&$ t&i$t"/lai!$? Et *N? & /&i%i!$? CHN. I! $ac" cas$ t"$ -OH &$acts fi&st as a !cl$"il$? attac#i!3 t"$ $l$ct&"ilic c$!t$& f t"$ "al3$!ati!3 a3$!t. A %islac$% "ali%$ i! t"$! cl$t$s t"$ s+stitti! %islaci!3 t"$ l$a=i!3 3&. Nt$ t"at it is not -OH t"at l$a=$s? +t a c" +$tt$& l$a=i!3 3&.

Subhasish sir

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T"$ a%=a!ta3$ f t"$s$ &$a3$!ts is i! t"at t"$ &$acti! is !t !%$& t"$ st&!3l/ aci%ic c!%iti!s li#$ si!3 HCl & H7&.

(3):& al#a!$s  Ra%ical S+stitti!

S!00a(y S+stitti! f R-H +/ -X &=i%$s t"$ al#/l "ali%$? R-X a!% HX. Al#a!$ R-H &$lati=$ &$acti=it/ &%$&  *  > ' > 1 > $t"/l Hal3$! &$acti=it/ :' > Cl' > 7&' > I' O!l/ c"l&i!ati! a!% +&i!ati! a&$ s$fl i! t"$ la+&at&/. R$acti! &c$$%s =ia a &a%ical c"ai! $c"a!is Ra%icals - A &a%ical is a s$ci$s t"at c!tai!s !ai&$% $l$ct&!s. T/icall/ f&$% +/ a "l/tic +!% cl$a=a3$ as &$&$s$!t$% +/ t"$ fis""# c&=$% a&&;s • • • • •

Sta$i"ity: T"$ 3$!$&al sta+ilit/ &%$& f sil$ al#/l &a%icals is (st sta+l$) *  > ' > 1 > $t"/l (l$ast sta+l$)

T"is is +$cas$ al#/l 3&s a&$ ;$a#l/ $l$ct&! %!ati!3 %$ t "/$&c!3ati! a!% i!%cti=$ $ff$cts. Nt$ t"at t"is is t"$ %a0e o(1e(  as f& ca&+cati!s. R$s!a!c$ $ff$cts ca! f&t"$& sta+ili8$ &a%icals ;"$! &$s$!t. St(!ct!(e:

Al#/l &a%icals a&$ s ' "/+&i%i8$%? la!a& s/st$s at t"$ &a%ical C c$!t$&. T"$ -&+ital t"at is !t tili8$% i! t"$ "/+&i%s c!tai!s t"$ si!3l$ $l$ct&!. Reacti-ity: As t"$/ "a=$ a! i!cl$t$ ct$t? &a%icals a&$ $5c$ll$!t $l$ct&"il$s a!% &$act &$a%il/ ;it" !cl$"il$s. Alt$&!ati=$l/? lss f H . ca! 3$!$&at$ a  +!% Rea((an/e0ent%: U!li#$ ca&+cati!s? &a%icals % !t t$!% t !%$&3 &$a&&a!3$$!ts Reaction% in-o"-in/ (a1ica"%: Ra%ical "al3$!ti! f al#a!$s RADICAL CHAIN +ECHANIS+ FOR REACTION OF +ETHANE ,ITH B( ) Ste ' &Initiation* H$at & = li3"t cas$ t"$ ;$a# "al3$! +!% t !%$&3 "l/tic cl$a=a3$ t Subhasish sir

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3$!$&at$ t; +&i!$ &a%icals a!% sta&ti!3 t"$ c"ai! &c$ss. Ste ) &P(oa/ation* (a) A +&i!$ &a%ical a+st&acts a "/%&3$! t f& H7& a!% a $t"/l &a%ical? t"$! (+) T"$ $t"/l &a%ical a+st&acts a +&i!$ at f& a!t"$& l$cl$ f 7& 't f& t"$ $t"/l +&i%$ &%ct a!% anot#e( +&i!$ &a%ical? ;"ic" ca! t"$! its$lf !%$&3 &$acti! '(a) c&$ati!3 a c/cl$ t"at ca! &$$at. Ste 3 &Te(0ination* 9a&is &$acti!s +$t;$$! t"$ ssi+l$ ai&s f &a%icals all; f& t"$ f&ati! f $t"a!$? 7&' & t"$ &%ct? $t"/l +&i%$. T"$s$ &$acti!s &$=$ &a%icals a!% % !t $&$tat$ t"$ c/cl$.

S$l$cti=it/ T"$&$ a&$ t; c!$!ts t !%$&sta!%i!3 t"$ s$l$cti=it/ f &a%ical "al3$!ati!s f al#a!$s &$acti=it/ f R-H s/st$ &$acti=it/ f X. RH T"$ st&$!3t" f t"$ R-H =a&i$s sli3"tl/ %$$!%i!3 ! ;"$t"$& t"$ H is 1 ? ' & *. T"$ fll;i!3 ta+l$ s";s t"$ +!% %issciati! $!$&3/? t"at is t"$ $!$&3/ &$i&$% t +&$a# t"$ +!% i! a "l/tic fas"i!? 3$!$&ati!3 R . a!% H. • •

Tye

RH 2560o" 2ca"60o" CH*-H 437 '84 Nt$ "; t"$ +!%s 3$t ;$a#$& as ;$ =$ %;!  1 CH*CH'-H 4'8 9 t"$ ta+l$? s t"$ R . als 3$t $asi$& t f&? ;it" * +$i!3 t"$ $asi$st. ' (CH*)'CH-H 39; 97 * (CH*)*C-H 38 9' Ha"o/en (a1ica"< =. 7&i!$ &a%icals a&$ l$ss &$acti=$ t"a! c"l&i!$ &a%icals 7&. t$!%s t +$ &$ s$l$cti=$ i! its &$acti!s? a!% &$f$&s t &$act ;it" t"$ ;$a#$& R-H +!%s. T"$ &$ &$acti=$ c"l&i!$ &a%ical is l$ss %isc&ii!ati!3 i! ;"at it &$acts ;it". • •

•

Ra%ical Hal3$!ati! f Al#a!$s

Reaction tye: Ra1ica" S!$%tit!tion Subhasish sir

Page 8

s$c!%a&/ > &ia&/ > $t"/l. Hal3$! &$acti=it/ :' > Cl' > 7&' > I' O!l/ c"l&i!ati! a!% +&i!ati! a&$ s$fl i! t"$ la+&at&/. 7&i!ati! is s$l$cti=$ f& t"$ R-H t"at 3i=$s t"$ st sta+l$ &a%ical. C"l&i!ati! is l$ss s$l$cti=$ R$acti! &c$$%s =ia a! &a%ical c"ai! $c"a!is ;"ic" i!=l=$s &a%ical i!t$&$%iat$s. T"$ t$&i!ati! st$s a&$ f l; &+a+ilit/ %$ t t"$ l; c!c$!t&ati! f t"$ &a%ical s$ci$s $a!i!3 t"at t"$ c"a!c$s f t"$ clli%i!3 is =$&/ l;. I%i!ati! f $t"a!$ &$i&$s $&i%ic aci% & !it&ic aci% as 5i%isi!3 a3$!ts. (3) 7/ 7&%i!$ H!s%ic#$& &$acti!  • • • • • • • •

•

(") :& al#/l "ali%$s

(i) :& sl"&/l c"l&i%$ 

() 7/ Da&3$!s $t"% 

(#) 7/ si!3 N7S  N B(o0o%!ccini0i1e &NBS*

N -7&scci!ii%$ (N7S) is a +&i!ati!3 a!% 5i%i8i!3 a3$!t t"at is s$% as s&c$ f& +&i!$ i! &a%ical &$acti!s (f& $5al$ all/lic +&i!ati!s) a!% =a&is $l$ct&"ilic a%%iti!s. T"$ N7S +&i!ati! f s+st&at$s sc" as alc"ls a!% ai!$s? fll;$% +/ $lii!ati! f H7& i! t"$ &$s$!c$ f a +as$? l$a%s t t"$ &%cts f !$t 5i%ati! i! ;"ic" ! +&i!$ "as +$$! i!c&&at$%. Subhasish sir

Page 9

Na0e Reaction%

(l) ,&$a&ati! f& al#$!$s ;$ #!; t"at al#$!$s a&$ !sat&at$% "/%&ca&+!s.T"$&$f&$ ;"$! al#$!$s a&$ t&$at$% ;it" "al3$! aci%? a%%iti! &$acti! ta#$s lac$ a!% al#/l "ali%$s a&$ f&$%. A%%iti!f HX ta#$s lac$ acc&%i!3 t +ARKONIKO>?S PRINCIPLE. CH) @ CH)  HC"  CH 3  CH)  C" CH3CH@CH)  HB(  CH3CHB(CH3 T"$ &%$& f &$acti=it/ f "al3$! aci% is as fll;s HI  HB(  HC" () All/lic "al3$!ati!s Ra1ica" Ha"o/enation o A""y"ic %y%te0%

Reaction tye: Ra1ica" S!$%tit!tion