Formal Report on Sublimation

SUBLIMATION Pamela Estrada, Estrada, Carlo Falconi, Shina Go, Joana Gozon, Monica Hamtig, and Caitlin Hao. Group 4 2F Medical Technology Technology Organic Chemitry !a"oratory

ABSTRACT Thi e#periment $a per%ormed o a to puri%y "enzoic acid uing u"limation, to determine and compare the melting point o% the product $ith a tandard, and to "e a"le to calculate the percentage reco&ery. 'n e&aporating dih %illed $ith (.))g o% impure "enzoic acid that i co&ere co&ered d $ith a per%or per%orate ated d paper paper and an in&ert in&erted ed $atch gla $a heated heated uing a hot plate, plate, and cooled cooled $ith $ith a $et tiue paper imultaneouly %or *)+*( minute. '%ter thi part o% the procedure, the et+up $a allo$ed to cool. 'll the u"limate that $ere adhering to the $atch gla and per%orated paper $ere collected and $eighed to "e a"le to compute %or the percentage reco&ery. The u"limate $a then grounded into a %ine po$der and $a compared $ith a pure "enzoic acid "y determining the melting point range through the ue o% an oil "ath o a to ditinguih the purity o% the product.

INTRODUCTION enzoic enzoic 'cid i a $hite, $hite, crytallin crytalline e organic organic compound that "elong to the the %amily o%  car"o#ylic acid-*. /t i lightly olu"le in $ater and ha a melting point o% *22 degree Celiu-2. Su"limation i the direct &aporization o% a olid "y hea heatin ting g $it $ithou houtt pa pain ing g thr throug ough h the li0 li0uid uid tate-1. /n order to puri%y the impure "enzoic acid, the proce o% u"limation $a ued in thi e#periment e#per iment.. The impuritie impuritie in the "enzo "enzoic ic acid contain amino compound that can "e %ound at a greater limit and mut "e taen a$ay "ecaue o%  pheny phe nyll an and d "en "enzyl zyl com compou pound nd tha thatt e#t e#trem remely ely a%%ect the product o% the reaction. Thi proce occur $hen the &apor preure o% the u"tance i greater than that o% the atmopheric preure at the melting point. The puri%ic pur i%icati ation on pro proce ce  in& in&ol& ol&ed ed in u" u"lim limati ation on i more mor e app applic lica"l a"le e %or imp impuri uritie tie  $it $ith h lo$ &a &apor por preure or non+&olatile than pure u"tance or compound-4. The melting point o% an organic compound i one o% e&eral phyical propertie "y $hich it i iden id enti ti%i %ied ed,, o on one e $a $ay y to te tet t th the e pu puri rity ty o% a u"tanc u" tance e i "y determ determining ining it melting point. ' pure u"tance generally ha a melting range o%  one one or t$o t$o degre egree e.. Thi Thi i the the di%% di%%er eren ence ce "et$ee "et$een n the temper temperatu ature re at $hich $hich the ampl ample e tart to melt and the temperature at $hich the ample mple com complet pletel ely y melte elted. d. The The ample mple33 impu impuri riti tie e tend tend to depr depre e  and and "roa "roade den n the the melting range o the puri%ied ample hould ha&e a high higher er and and mal malle lerr melt meltin ing g rang range e than than the the original, impure ample-(. The o"ecti&e o% thi e#periment are5 6*7 To puri puri%y %y the impure impure "enzoic "enzoic acid acid through through u"limation. 627 To calcula calculate te the percent percentage age reco&e reco&ery ry o%  the "enzoic acid a%ter u"limation. 617 To id iden enti ti%y %y th the e me melt ltin ing g po poin int t o% th the e u"l u "lim imat ate e an and d th the e pu pure re "e "enz nzoi oic c ac acid id through the ue o% an oil "ath.

EXPERIMENTAL A. Compoun Compounds ds teste tested d (or (or Sample Samples s used used

'$&ure ". Stru!tural 'ormula o Ben)o$! A!$d

The teted in

compound thi e#periment i only "enzoic acid "ut the group made ue o% it pure and impure %orm. The pure "enzoic acid $a the tandard $hile the impure "enzoic acid $a e#perimented on. enzoic acid i a $hite, crytalline organic compound-*, $hich ha a melting point o% *228C and ha a "oiling point o% 2498C at :;) mmHg or * atm. /t molecular %ormula i C :H;O2 and and it ha ha a +COO +COOH H %unc %uncti tion onal al grou group, p, mai maing ng it a car"o#ylic acid-;. B. Pro!edu !edure re ". Su#l$m #l$ma at$on $on To tart, (.))g o% impure "enzoic acid $a placed in an e&apor e&aporati ating ng dih, dih, and co&ered co&ered $ith a per%or per%orate ated d "ond "ond paper and an in&erted $atch gla. 'll opening $ere ecured $ith maing tape o a not to allo$ the &apor to ecape ecape %rom the et+up. et+up. Thi et+up et+up $a $a then heated heated uing a hot plate %or *)+*( minute until mot o% the ample $ere &aporized, a the center top o% the et+up $a cooled $ith a $et tiue paper that i ept moit $ith $ater. '%ter heating, the et+up $a allo$ed to cool, and the u"limate, in the %orm o% crytal, adhering to the ur% ur%ac ace e o% the the $atc $atch h gla gla and and paper paper $a $a care% care%ul ully ly collected and $eighed. The $eight o% the u"limate and the the $eigh $eightt o% the amp ample le $ere $ere ued ued to calcu calcula late te the the percentage reco&ery. %. Melt$ Melt$n& n& Po$n Po$ntt Deter Determ$n m$nat at$on $on To determine the melting point o% the product, the u"limate $a %irt pul&erized into a %ine po$der, and then placed in a capillary tu"e that i ealed on one end. The u"limate $a then paced at the "ottom o% the capillary

tu"e "y repetiti&ely dropping the cloed end o% the capillary tu"e through a gla tu"ing. Thi $a alo done $ith a pure "enzoic acid to ue a a tandard %or comparion $ith the product. The amount o% the u"limate and the tandard $ere o% the ame height in the capillary tu"e, auming "oth are $ell+paced and properly la"eled. Then, "oth $ere aligned $ith and attached to the mercury "ul" o% the thermometer. Thi et+up $a then immered in an oil "ath and heated. The initial temperature at $hich the u"limate and the tandard tart to melt and the %inal temperature at $hich the u"limate and the tandard completely melted $ere recorded.

Thermometer

Oil ath

Capillary tu"e ?itilled $ater to eep the tiue paper moit

Ga Source

unen urner >et tiue paper o&er the $atch gla

=&aporating dih $ith impure "enzoic acid co&ered $ith per%orated paper and in&erted $atch gla

*. Computat$ons '%ter the u"limate $a $eighed, computation $ere done. The percentage reco&ery o% the "enzoic acid $a then calculated uing the %ormula "elo$.