Formal Report- Elimination

8/9/2019 Formal Report- Elimination

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Traya, Levie Grace M. 6 September 2014BS Chemistry 4

ELIMINATION(27 August 2014)

I. INTR!"CTIN

The #ehy#rati$% $& a'c$h$' is a% imp$rta%t e'imi%ati$% reacti$% that ta(es

p'ace )%#er aci#ic rather tha% basic c$%#iti$%. It i%v$'ves a% *1 mecha%ism. The

&)%cti$% $& the aci#ic rea+e%t is t$ c$%vert the hy#r$y' +r$)p t$ a better 'eavi%+

+r$)p by pr$t$%ati$%- 1/

This e'imi%ati$% reacti$% is the reverse $& aci#cata'ye# hy#rati$%. Beca)se

a carb$cati$% $r c'$se'y re'ate# species is the i%terme#iate, the e'imi%ati$% step

$)'# be epecte# t$ &av$r the m$re s)bstit)te# a'(e%e. The *1 mecha%ism a's$

ep'ai%s the +e%era' tre%# i% re'ative reactivity. Tertiary a'c$h$'s are the m$st

reactive, a%# reactivity #ecreases +$i%+ t$ sec$%#ary a%# primary a'c$h$'. 3's$

i% acc$r# ith *1 mecha%ism is the &act that rearra%+e# pr$#)cts are &$)%# i%

cases here a carb$cati$% i%terme#iate $)'# be epecte# t$ rearra%+e- 2/

$r ma%y a'c$h$'s, echa%+e $& the hy#r$y' +r$)p ith s$'ve%t c$mpetes

ith #ehy#rati$%. This echa%+e i%#icates that the carb$cati$% ca% )%#er+$ SN1capt)re i% c$mpetiti$% ith e'imi%ati$%. "%#er c$%#iti$%s here pr$t$% rem$va'

is rate#etermi%i%+, it $)'# be epecte# that si+%i5ca%t is$t$pe eect $)'# be

see%. This is, i% &act, $bserve#.

I% c$%%ecti$% t$ the &acts state# this eperime%t aims t$ )%#ersta%# the

c$%cept $& e'imi%ati$% a%# sy%thesie a% a'(e%e &r$m a% a'c$h$' a%# test it )si%+

p$tassi)m perma%+a%ate test a%# br$mi%e test.

II. M*T7!LG8


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3. Materia's

Tertb)ty' a'c$h$' 290mL r$)%#b$tt$me#

:as(

Therm$meter h$'#er

C$%c. 72S4 ;ipet 3'c$h$' 'amp

CaC'2 3spirat$r Separat$ry &)%%e'3cet$%e Therm$meter G'ass #r$pper1< 3=)e$)s

>M%4

Re:) c$%#e%ser Re'&)

set)p/

?ire +a)e

Carb$%

tetrach'$ri#e

Ir$% sta%#

2< br$mi%e Ir$% ri%+

B. ;r$ce#)re

I% a 290mL r$)%#b$tt$me# :as(, a 14mL $& ater a%# c$%c. 72S4 as a##e#. The aci# as the% c$$'e# t$ ab$)t 90 ℃ a%# a 12.6mL $&

tb)ty' a'c$h$' as s'$'y a##e# t$ the s$')ti$%. The s$')ti$% as the%

s)b@ecte# t$ re:) here it as e%s)re# that %$ steam sh$)'# be pr$#)ce

$r there i'' be 'esser perce%ta+e yie'#.

The s$')ti$% as the% c$$'e# at r$$m temperat)re a%# the%

tra%s&erre# t$ a separat$ry &)%%e' here the a=)e$)s aci# 'ayer as

care&)''y #ra%. The hy#r$carb$% 'ayer as the% ashe# ith ater i%

$r#er t$ rem$ve traces $& aci#.

!)e t$ 'imite# res$)rces, the eperime%t as c)t t$ this part a%# the

hy#r$carb$% as the% imme#iate'y s)b@ecte# t$ the p$tassi)m

perma%+a%ate test a%# br$mi%e test t$ chec( &$r the prese%ce $& a'(e%e.

;$tassi)m perma%+a%ate test as #$%e by a##i%+ A #r$ps $& the

a'(e%e s$')ti$% i% a 1mL acet$%e a%# ith vi+$r$)s sha(i%+ the 1<

3=)e$)s >M%4 as a##e#. The test $)'# be p$sitive i& ithi% 1 mi%)te

the p)rp'e c$'$r i'' &a#e a%# there i'' be a &$rmati$% $& i%s$')b'e br$%

hy#rate# $i#es $& ma%+a%ese.

Br$mi%e test as carrie# $)t i% a h$$#. It as #$%e by a##i%+ A #r$ps$& the a'(e%e s$')ti$% t$ a 1mL br$mi#e i% carb$% tetrach'$ri#e. The test

$)'# be p$sitive i& there i'' be a '$ss i% the br$% c$'$r $& the s$')ti$%.


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III. !3T3 3N! R*S"LTS

Tab'e 1. bservati$% &$r p$tassi)m perma%+a%ate test

Be&$re the test 3&ter the test

i$'et s$')ti$% Br$% i%s$')b'e s$')ti$%

Tab'e2. bservati$% &$r br$mi%e test

Be&$re the test 3&ter the testBr$% s$')ti$% Became a c$'$r'ess s$')ti$%

I. !ISSC"SSIN INT*R;R*T3TIN R*S"LTS

Ma%y sec$%#ary a%# tertiary ha'i#es )%#er+$ *1 e'imi%ati$% i% c$mpetiti$%

ith the SN1 reacti$% i% %e)tra' $r aci#ic s$')ti$%s. $r this eperime%t, he%

tertb)ty' a'c$h$' s$'v$'yes i% s)'&)ric aci# it pr$#)ce #iis$b)ty'e%e by

e'imi%ati$%.

3'c$h$'s a%# ethers rare'y )%#er+$ s)bstit)ti$% $r e'imi%ati$% )%'ess str$%+

aci# is prese%t. The aci# is %ecessary t$ c$%vert a re'ative'y p$$r 'eavi%+ +r$)p,

7 &$r this partic)'ar eperime%t, i%t$ a re'ative'y +$$# $%e, 72. Th)s the

#ehy#rati$% $& a'c$h$'s t$ a'(e%es is a% aci#cata'ye# reacti$% re=)iri%+ str$%+

aci#s. I% this eperime%t, the starti%+ materia' as a% a'c$h$', tertb)ty' a'c$h$',

as reacte# t$ a% aci#, s)'&)ric aci#, t$ pr$#)ce #iis$b)ty'e%e. The mecha%ism

as sh$% as &$''$s- A/

L$$(i%+ at the reacti$%, %$tice that ater is a pr$#)ct $& the #ehy#rati$%

reacti$%. I% the mecha%ism sh$%, the starti%+ materia' as reacte# ith

s)'&)ric aci# here the aci# c$%verte# the p$$r 'eavi%+ +r$)p 7 i%t$ 72 hich


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is a better 'eavi%+ +r$)p. The 'eavi%+ +r$)p the% c'eaves $)t pr$#)ci%+ the

carb$cati$% here it as attac(e# by the base. The base rem$ves a betapr$t$%,

'eavi%+ behi%# its b$%#i%+ e'ectr$%s t$ &$rm the %e #$)b'e b$%#.

!)e t$ sh$rta+e $& rea+e%ts the pr$ce#)re as c)t a&ter the hy#r$carb$% as

is$'ate#. The hy#r$carb$% as s)b@ecte# t$ t$ c$%5rmat$ry tests %ame'yp$tassi)m perma%+a%ate test a%# br$mi%e test.

$r br$mi#e test, the br$% s$')ti$% became c$'$r'ess hich i%#icates a

p$sitive test aDrmi%+ the prese%ce $& a'(e%e. The Br$mi%e test &$r the a'(e%e

cr)#e pr$#)ct as p$sitive beca)se br$mi%e is e'ectr$% #e5cie%t a%# a'(e%es

have pi e'ectr$%s &$rmi%+ a #$)b'e b$%# that are $pe% &$r attac(. The reacti$% is-

4/

!)e t$ their CEC #$)b'e b$%#s hich ca% be br$(e%, a'(e%es react rea#i'y

ith br$mi%e t$ pr$#)ce sat)rate# #ibr$m$a'(a%es. I% the prese%ce $& Br2 $r Br

Br hich is re#br$%/, the BrBr b$%# attac(s the #$)b'e b$%# &$rmi%+ CBr

%e b$%#s. Th)s the re#br$% c$'$r #isappears.

I% the p$tassi)m test, the vi$'et s$')ti$% t)r%e# i%t$ a br$% i%s$')b'e

s$')ti$%. Be'$ is the reacti$% e=)ati$% $& the sai# test- 9/

"%#er aci#ic c$%#iti$%s, the ma%+a%ateII/ i$%s ere re#)ce# t$

ma%+a%eseII/ i$%s. "%#er a'(a'i%e c$%#iti$%s, the ma%+a%ateII/ i$%s are 5rst

re#)ce# t$ +ree% ma%+a%ateI/ i$%s a%# the% &)rther t$ #ar( br$% s$'i#

ma%+a%eseI/ $i#e ma%+a%ese #i$i#e/. The 'ast reacti$% is a's$ the $%e that

$)'# $btai%e# i& the reacti$% as #$%e )%#er %e)tra' c$%#iti$%s. 3%# as see% i%

the reacti$%, there are %either hy#r$+e% i$%s %$r hy#r$i#e i$%s $% the 'e&tha%#

si#e $& the e=)ati$%.

. CNCL"SIN 3N! R*CMM*N!3TIN


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F)st as there ere t$ mecha%isms &$r %)c'e$phi'ic s)bstit)ti$%, there are

t$ e'imi%ati$% mecha%isms. $r this eperime%t, it &$''$e# the *1 mecha%ism.

The *1 mecha%ism is %ear'y i#e%tica' t$ the SN1 mecha%ism, #ieri%+ $%'y i% the

c$)rse $& reacti$% ta(e% by the carb$cati$% i%terme#iate.

3s sh$% by the &$''$i%+ e=)ati$%s, a carb$cati$% beari%+ betahy#r$+e%s

may &)%cti$% either as a Leis aci# e'ectr$phi'e/, as it #$es i% the SN1 reacti$%,

$r a Br%ste# aci#, as i% the *1 reacti$%.

Th)s, hy#r$'ysis $& tertb)ty' a'c$h$' i% a mie# s$'ve%t $& ater a%# s)'&)ric

aci# +ives a pr$#)ct is$b)ty'e%e a%# &)rther reacti$% +ives a pr$#)ct#iis$b)ty'e%e at a rate i%#epe%#e%t $& the ater c$%ce%trati$%. !iis$b)ty'e%e

as pr$#)ce# beca)se is$b)ty'e%e is a% )%stab'e pr$#)ct a%# th)s react

&)rtherm$re ith the carb$cati$% bei%+ create#. The a'c$h$' is the pr$#)ct $& a%

SN1 reacti$% a%# the a'(e%e is the pr$#)ct $& the *1 reacti$%. The characteristics

$& these t$ reacti$% mecha%isms are simi'ar, as epecte#. They b$th sh$ 5rst

$r#er (i%eticsH %either is m)ch i%:)e%ce# by a cha%+e i% the %)c'e$phi'ebaseH

a%# b$th are re'ative'y %$%stere$speci5c.

T$ s)mmarie, he% carb$cati$% i%terme#iates are &$rme# $%e ca% epect

them t$ react &)rther by $%e $r m$re $& the &$''$i%+ m$#es-

1. The cati$% may b$%# t$ a %)c'e$phi'e t$ +ive a s)bstit)ti$% pr$#)ct.

2. The cati$% may tra%s&er a betapr$t$% t$ a base, +ivi%+ a% a'(e%e pr$#)ct.

A. The cati$% may rearra%+e t$ a m$re stab'e carb$cati$%, a%# the% react by

m$#e 1 $r 2.

Si%ce the SN1 a%# *1 reacti$%s pr$cee# via the same carb$cati$%

i%terme#iate, the pr$#)ct rati$s are #iDc)'t t$ c$%tr$' a%# b$th s)bstit)ti$% a%#

e'imi%ati$% )s)a''y ta(e p'ace.

The is$'ate# cr)#e pr$#)ct #i# c$%tai% a'(e%e as sh$% i% the res)'ts $& the

t$ tests %ame'y p$tassi)m perma%+a%ate test a%# br$mi%e test. The

p$tassi)m perma%+a%ate test as p$sitive #)e t$ the appeara%ce $& br$%

i%s$')b'e s$')ti$% hich as #)e t$ the hy#rate# $i#e ma%+a%ese. 3%# the

is$'ate# cr)#e pr$#)ct as p$sitive hich aDrms the prese%ce $& hy#r$carb$%s.


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I. R**R*NC*S

B$$(s-

Br)ice, ;a)'a 8. r+a%ic Chemistry. 4th e#. ;ears$% ;re%tice 7a''. 2004

B$y#, R. N. J M$rris$%, R.T. r+a%ic Chemistry. 6th *#. ;re%tice 7a''.

1KK2

Carey, ra%cis 3. r+a%ic Chemistry. 4th e#. McGra7i''. 2000

Cha%+, Reym$%#. Chemistry. 10th e#. McGra7i''. 2010

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?eb-

*1 Reacti$%. Chem?i(i. Retrieve# $% A 3)+)st 2014, &r$m

http-chemi(i.)c#avis.e#)r+a%icChemistryReacti$%s*1Reacti$%

*'imi%ati$% reacti$s. C7IM*. Retrieve# $% 4 September 2014, &r$m

http-.mhhe.c$mphysscichemistrycareyst)#e%t$'c+raphicscarey0

4$cre&ch09e'imi%ati$%reacti$%s.htm'

*;L3INING T7* *LIMIN3TIN R*3CTINS ;R!"CING 3L>*N*S RM

SIM;L* 73LG*N3L>3N*S. ChemG)i#e. Retrieve# $% 4 September 2014,

&r$m http-.chem+)i#e.c$.)(mecha%ismse'ime'imtt.htm'

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http-.master$r+a%icchemistry.c$m20111010i%tr$#)cti$%t$

e'imi%ati$%reacti$%s
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