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Chhiimma a NNwwaakkppuuddaa DDaatte e PPeerrffoorrmmeed d iin n LLaabb: : MMaarrcch h 2200, , 22001155 T
T: : !e" !e" #o$a! #o$a! Due Due Date Date of of %eport: %eport: March March 2&, 2&, 20152015 Experiment 8B
Experiment 8B: '(terification %eaction ) *(opent+! cetate, and the u(e : '(terification %eaction ) *(opent+! cetate, and the u(e of cidic %e(in(of cidic %e(in( Objective
Objective: Thi( e"periment e"p!ore( the : Thi( e"periment e"p!ore( the c!a((ic reaction( of carbo"+!ic acid( with a!coho!(,c!a((ic reaction( of carbo"+!ic acid( with a!coho!(, in the pre(ence of acid cata!+(t, to +ie!d e(ter( with the addition o
in the pre(ence of acid cata!+(t, to +ie!d e(ter( with the addition o f water *n the !ab thef water *n the !ab the ph+(ica! propertie( of the(e e(terification product( are e"amined and the techni-ue of .a( ph+(ica! propertie( of the(e e(terification product( are e"amined and the techni-ue of .a( chromato.raph+ wa( app!ied to the purification of the(e materia!( The a!coho! u(ed in chromato.raph+ wa( app!ied to the purification of the(e materia!( The a!coho! u(ed in thi(thi( reaction wa( i(opent+! a!coho! with the carbo"+!ic acid acetic acid in the pre(ence
reaction wa( i(opent+! a!coho! with the carbo"+!ic acid acetic acid in the pre(ence of acidof acid cata!+(t (u!furic acid
cata!+(t (u!furic acid Experimental Procedure
Experimental Procedure: The procedure wa( fo!!owed a( de(cribed in : The procedure wa( fo!!owed a( de(cribed in Ma+o, pa.e( 201)Ma+o, pa.e( 201) 202, with the fo!!owin. modification(:
202, with the fo!!owin. modification(: Reagents and Equipment
Reagents and Equipment / The reaction wa( (et up on
/ The reaction wa( (et up on a (ca!e of what i( de(cribed in a (ca!e of what i( de(cribed in the !ab te"tbookthe !ab te"tbook / 50)mL conica! $ia! wa( (ti!!
/ 50)mL conica! $ia! wa( (ti!! u(edu(ed
/ ub(tituted Drierite for ca!cium ch!oride in the dr
/ ub(tituted Drierite for ca!cium ch!oride in the dr +in. tube+in. tube Reaction Conditions
Reaction Conditions
/ Did not (top the (pin $ane
/ Did not (top the (pin $ane whi!e the reaction mi"ture wa( coo!in. to rowhi!e the reaction mi"ture wa( coo!in. to ro om temperatureom temperature %ai(ed the $ia! out of the (and
%ai(ed the $ia! out of the (and bath to be.in coo!in., but not bath to be.in coo!in., but not (o hi.h that the (pin $ane(o hi.h that the (pin $ane (topped rotatin.
(topped rotatin.
/ Did not cut the amount
/ Did not cut the amount of dieth+! ether in ha!f, but added of dieth+! ether in ha!f, but added the fu!! 05 mLthe fu!! 05 mL / 3hen remo$in. the (pin $ane
/ 3hen remo$in. the (pin $ane with forcep( or a wand ma.newith forcep( or a wand ma.net, u(ed the dieth+! ether 405t, u(ed the dieth+! ether 405 mL to rin(e the (pin $ane
mL to rin(e the (pin $ane 4an+ product remainin. on the (pin 4an+ product remainin. on the (pin $ane wa( then wa(hed back$ane wa( then wa(hed back into the %eaction $ia!
into the %eaction $ia! Isolation of Product Isolation of Product / Continued on a
/ Continued on a (ca!e of what i( de(cribed in the !ab (ca!e of what i( de(cribed in the !ab te"tbook and cut in ha!f a!! workupte"tbook and cut in ha!f a!! workup mount(
mount(
/ Did not di(ti!! product Tran(ferred dried ether (o!ution containin. the product to / Did not di(ti!! product Tran(ferred dried ether (o!ution containin. the product to t
tared, (crew)cap te(t ared, (crew)cap te(t tubetube
/ Concentrated the crude product (o!ution a( u(ua! 6btained
/ Concentrated the crude product (o!ution a( u(ua! 6btained the product wei.htthe product wei.ht Purification and Characterization
Purification and Characterization
/ The crude product wa( ana!+7ed b+ .a( chromato.raph / The crude product wa( ana!+7ed b+ .a( chromato.raph ++ Chemical
Chemical TeTestssts / 6mit thi( (tep / 6mit thi( (tep Reaction Scheme Reaction Scheme::
Data and Results:
Compound Mo!ecu!ar 8ormu!a M3 mount mmo! bp4C d
*(opent+! !coho! C59126 15 ;00 uL <& 1<2 01
cetic cid C29;62 =01 &50 uL 1<1 11= 105
u!furic cid, concd 926; 2 drop(
Product: *(opent+! acetate C&91;62 1<01> ;1= m. <2 1;2 0 Observations:
• *(opent+! a!coho! ? cetic cid ? u!furic cid wa( a brown (o!ution • The reaction produced a p!ea(ant odor
• o!ution wa( heated for an hour at a temperature of 1=0)10 de.ree( Ce!(iu(
• ddition of 5@ Na9C6< created two !a+er( ) top !a+er wa( +e!!ow, bottom !a+er wa( c!ear
• i!ica .e! wa( white (o!id
• The product wa( a !i.ht +e!!ow !i-uid Calculations:
1 Theoretica! Aie!d
(Limiting reagent) x (1/Molecular weight of limiting reagent) x (stoichiometry ratio) x (MW of Isopentyl acetate) or (mmol of limiting reagent) x (stoichiometry ratio) x (MW of Isopentyl acetate)
• ( 3.7 mmol of iosopentyl alcohol) x (1/1 ratio) (1<01> .Bmo! of *(opent+! acetate 48
mg o Isopentyl acetate 2 Aie!d of i(opent+! acetate
(est tu!e " !oiling stone " pro#uct) $ (est tu!e " !oiling stone) % &ru#e 'ro#uct • (11.1 g) $ (11.*+* g) %.416 g or 416 mg of crude product
< Percent Aie!d of i(opent+! acetate
(,ctual yiel#/theoretical yiel# x 1--) % percent yiel# • (.1+g) / (.g) x 1-- %86.6 % yield
; C %etention Time
('ea from the #istance !etween the 0ero point line an# the top of the pea) x (1min/cm) 'ea 1
1.1 cm x (1min/cm) %1.1 min retention time
'ea
. cm x (1min/cm) % 2.9 min retention time
'ea 3
*.cm x (1min/cm) % 5.4 min retention time
5 C Peak rea
(2eight of the pea (in mm) x (Wi#th at half height (in mm) 'ea 1 . cm x .1cm % . cm %22 mm^2 peak area 'ea .cm x .1cm % .- cm %2 mm^2 peak area 'ea 3 +.cm x .cm % .7+ cm %276 mm^2 peak area = C Peak *dentit+
Peak 1 acetic acid
Peak 2 !sopent"l alcohol Peak < !sopent"l acetate
#uestions: 1
2 n e"p!anation for the order of m+ e!ution i( that the e(ter had the .reate(t retention time meanin. that it took the !on.e(t for thi( compound to tra$e! from the inEection point to the detector becau(e it had the hi.he(t boi!in. point (o it can be (een a( peak three The a!coho! which had the (econd hi.he(t boi!in. poi nt wa( peak two 8ina!!+ the acetic acid which had the !owe(t boi!in. point wa( peak one becau(e it tra$e!ed the fa(te(t from the inEection point to the detector
< The peak area( for acetic acid, i(opent+! a!coho!, and i(opent+! acetate were 22 mm2, 2 mm2, and 2&= mm2 re(pecti$e!+ The combined area of the peak( i( <00 mm2 The purit+ of the crude product e(ter wou!d be 42&= mm2 B <00 mm2 " 100 which i( e-ua! to >20@ purit+
; a !ar.e e"ce(( of acetic acid u(ed in thi( fi(cher e(terification wa( u(ed to dri$e the reactant( to the product( 3ithout an e"ce(( amount the reaction wou!d be around the e-ui!ibrium and wou!dnFt fa$or comp!ete formation of the p roduct which wa( our .oa! b 3hen acetic acid wa( u(ed in e"ce(( for thi( reaction it wa( ea(i!+ (eparated from the product durin. the work up becau(e when (eparatin. the a-ueou( !a+er and the or.anic !a+er, the acetic acid (ta+( in the a-ueou( !a+er whi!e the i(opent+! acetate product (ta+( in the or.anic !a+er *(o!atin. the product wa( (imp!+ a matter of (eparatin. the two !a+er( 9owe$er, if an e"ce(( of i(opent+! a!coho! were u(ed in(tead, it wou!d be much harder to (eparate the a!coho! from the product becau(e both wou!d remain in the or.anic !a+er to.ether The a!coho! wou!d not be neutra!i7ed b+ the Na9C6< and wou!d (ta+ in the or.anic !a+er
$or%s Cited:
1Ma+o, D 3G Pike, %MG 8orbe(, DC Micro(ca!e 6r.anic Laborator + with Mu!ti(tep and Mu!ti(ca!e +nthe(i(, 5th edG Hohn 3i!e+ I on(, *nc, 2011G pp 1)202
2Modification( for '"pt: J '(terification %eaction ) *(opent+! cetate, J!ackboard document
