SCHOOL OF CHEMICAL & BIOMEDICAL ENGINEERING CHEMICAL & BIOMOLECULAR ENGINEERING
CH2801: CHEMICAL/ BIOMOLECULAR BIOMOLECUL AR ENGINEERING ENGINEERI NG LABORATORY LABORATORY 2A
Year Year 2: C7 Par!a" Par!a" M#"ar M#"ar $#"%e $#"%e ' (aer)E*a+#" S,-e.
Nae: Muhammad Ilyas Hassan Mar!%"a!#+ N%er: U1322800G N%er: U1322800G Gr#%: 9 Dae # E3er!e+: E3er!e+: 9 9th Sept 2014
14
A! The object!e o" the e#pe$ment e#pe$ment s to study pa$tal pa$tal mola$ p$ope$tes o" components n the m#tu$e by dete$mnn% pa$tal mola$ !olumes o" ethanol&'ate$ solutons(
24
A-ra M#n% substances to%ethe$ a$e cu$$ently a hea!y pa$t o" ou$ l!es( )e depend on m#tu$es all the tme as they a$e pa$t o" ou$ daly l!es* ou$ "ood+ d$n,s+ pet$ol+ ndust$es+ $esea$ch+ etc( -a$tal mola$ p$ope$tes a$e ntens!e the$modynamc p$ope$tes o" substances that consttutes a m#tu$e( These the$modynamc p$ope$tes p$ope$tes a$e mpo$tant n studes that n!ol!es m#tu$es as t dete$mnes the cont$buton o" a component to the $espect!e p$ope$tes p$ope$tes o" a m#tu$e+ $e.u$n% t as bass "o$ ou$ e.uaton balances /ene$%y+ mass+ momentum+ etc ( -a$tal mola$ p$ope$tes nclude pa$tal mola$ !olumes+ pa$tal mola$ enthalpes+ pa$tal mola$ Gbbs ene$%y+ etc 'hch a$e all ndependent o" the total amount o" m#tu$e but a$e dependent on the$modynamc the$modynamc condtons+ usually tempe$atu$e and p$essu$e+ dependn% on the p$ope$ty( In ths study+ 'e a$e "ocusn% nto pa$tal mola$ !olumes to help us "amla$se ou$sel!es 'th the concept o" pa$tal mola$ p$ope$tes(
54
Pr!+!"e ust l,e any othe$ chemcal p$ocesse#pe$ment+ 'e ha!e to unde$stand the theo$etcal concept and methodolo%y behnd the e#pe$ment( 541 Par!a" M#"ar $#"%e -a$tal mola$ !olume o" a component /component I "o$ e#ample may be consde$ed to be the chan%e n total !olume o" a m#tu$e 'hen 1 mole o" pu$e s added to an nnte amount o" a m#tu$e /o$ an amount so la$%e that ns%ncant concent$aton chan%e 'll $esult( -a$tal mola$ !olumes a$e o" consde$able nte$est as the$e a$e o"ten used n connecton 'th othe$ pa$tal mola$ .uanttes( o$ e#ample+ the chan%e n pa$tal mola$ Gbbs ene$%y 'th p$essu$e at constant tempe$atu$e s e.ual to pa$tal mola$ !olume as "ollo's( $om basc la's+ dGi 5 &Si dT 6 V i d-
Ma,n% 7 the subject+ /∂Gi ∂- T 5 V i
Mo$eo!e$+ the de$ence bet'een pa$tal mola$ !olume o" a component n a m#tu$e V i and ts mola$ !olume o" pu$e substance unde$ the same T and - s $elated to ts measu$e o" de!aton "$om deal soluton beha!ou$ o$ act!ty coe""cent+ acco$dn% to the "ollo'n% e.uaton: ln 5/1;T< -$e" /V i &V i d-
'he$e V i s the mola$ !olume o" pu$e measu$ed at the same T and - as the m#tu$e(
542 Der!6a!#+ # Par!a" M#"ar $#"%e The$e a$e se!e$al methds to dete$mne pa$tal mola$ !olumes( In ths study+ 'e 'll use the most common method+ the %$aphcal method based on appa$ent mola$ !olume = desc$bed by >e's and ;andall to nd the pa$tal mola$ !olumes o" absolute ethanol and ult$apu$e 'ate$ n a 'ate$ðanol bna$y system( The appa$ent mola$ !olume s %$aphed based on small nc$ements n concent$aton o" a substance to anothe$ substance 'hch consttutes majo$ty o" the bna$y m#tu$e( ?onsde$n% a bna$y m#tu$e consstn% o" t'o components+ component 1 ben% ult$apu$e 'ate$ and 2 ben% absolute ethanol+ the total !olume o" the m#tu$e s $elated to the$ $espect!e pa$tal mola$ !olumes+ V 1 and
V 2
as "ollo's:
t 7 5n1V 1 6n2V 2
/@.( 1
'he$e n1 and n2 a$e moles o" components 1 and 2 n the m#tu$e $espect!ely+ and V 1
5/
dVt A T+ -+ n2 d n1
/@.( 2
V 2
5/
dVt d n 2 T+ -+ n1
/@.( 3
I" the m#tu$e conssts o" a sol!ent /l.ud 'ate$ as component 1 and a solute /ethanol as component 2 o and let 71 be the mola$ !olume o" pu$e 'ate$ n mlmole at the same T and - as the m#tu$e+ the total
!olume s $elated to appa$ent mola$ !olume o" solute /component 2 = as: t o 7 5n1 71 6n2 =
/@.( 4
The solute appa$ent !olume may the$e"o$e be dened as "ollo's: t o =5/7 & n1 71 n2
/@.( B
$om e#pe$mentally measu$ed densty C /%ml o" the m#tu$e at T and -+ the total !olume o" the m#tu$e can be $elated to the molecula$ 'e%hts o" the components )1 and )2 n /%mol as "ollo's+ t 7 5/n1 )1 6 n2 )2C
/@.( D
Ho'e!e$+ t s con!enent to base on l000% /1 ,% o" pu$e 'ate$ 'th a densty o" C 1 /%ml at the T and - o" t measu$ement n a soluton o" total !olume 7 ( Hence o n1 71 5 1000 C1
/@.( E
and t 7 5/1000 6 n2 )2C
/@.( 8
@.( B can be $e'$tten as+ = 5 /1CF)2 & /1000n2 /C&C1C1 /@.( 9 Jy the denton o" pa$tal mola$ !olumes acco$dn% to @.s( /2 and /3 and the total !olume by @.s( /1 and /4+ V 2
t 6 n2 /d = 5 /d 7 d n2 T+ -+ n1 5 =
d
n2 T+ -+ n1
/@. 10 t o 2 5 /7 &n2 V 2n1 5 71 & /n2 n1/d = n2 T+-+n1 /@. 11 V 1
d
can be dete$mned The appa$ent solute !olumes = acco$dn% to @.( /9 "$om densty measu$ements o" pu$e sol!ent C1 and soluton m#tu$e C at the same T and - at de$ent n2( The plot o" = !e$sus n2 'll allo' the e!aluaton o" slopes / d = d n2 at de$ent n2( V 1 and V 2 can then be dete$mned "$om the abo!e @.s( /10 and /11(
/The molecula$ 'e%hts o" 'ate$ and ethanol a$e 18(01B and 4D(0E0 n %mol $espect!ely
4
Reae+-9 E%!e+ a+; Aara% The 3 man $ea%ents n ths e#pe$ment a$e ult$apu$e 'ate$+ absolute ethanol and acetone( Ult$apu$e 'ate$ and absolute ethanol a$e $ea%ents that a$e n!ol!ed n the bna$y m#tu$e n 'hch n!ol!es the$ pa$tal mola$ !olume calculatons 'hle acetone s used "o$ the cleann% and d$yn% o" densty measu$n% cell( The man e.upment used s a KML B000 denstomete$ "o$ densty measu$ements o" the m#tu$es and pu$e $ea%ents( the$ appa$atus ncludes common laba$ato$y e.upments ncludn% bu$ettes+ ppettes and concal Nas,s a$e used o" soluton p$epa$aton(
%u$e 1: Ima%e o" the KMLB000 <4
Pr#e;%re The e#pe$ment s "a$ly a st$a%ht&"o$'a$d one 'th 3 man pa$ts* p$epa$aton o" solutons+ measu$ement o" m#tu$e denstes+ and calculatons "o$ $esults( L b$e" outlne o" the p$ocedu$e s lsted belo'( 'a. Preara!#+ # =aer)e*a+#" -#"%!#+Solutons o" ethanol n 'ate$ contann% 0+ B+ 10+ 1B+ 20+ 30 and 40 !olume O a$e p$epa$ed( The !olumes o" ethanol and 'ate$ a$e measu$ed out accu$ately nto %lass&stoppe$ed bottle o$ concal Nas,s usn% bu$ettes o$ ppettes at $oom tempe$atu$e( L total o" 2Bml "o$ each soluton s $e.u$ed "o$ densty measu$ements( '. De+-!, ;eer!+a!#+ The densty o" each soluton s measu$ed accu$ately at o o a p$eset tempe$atu$e o" 20 ? o$ 30 ? usn% the KMLB000 denstomete$ as "ollo's: 1( Tu$n on the KMLB000 usn% the po'e$ s'tch and 'at "o$ %$een l%ht "o$ an ndcaton that the machne s $eady "o$ use( 2( ?hec, that the densty cell has al$eady been tho$ou%hly cleaned to $emo!e all "o$e%n substances and d$ed( ?leann% and d$yn% p$ocedu$e:
/ ll the measu$n% cell 'th ult$apu$e 'ate$ usn% a sy$n%e 'th >ue$ tp and attach t to the lln% noPPle( Mo!e the plun%e$ o" the sy$n%e n and out se!e$al tmes to "acltate cleann%( ;emo!e the cleann% 'ate$( 1 / ;epeat the abo!e cleann% p$ocess 'th pu$e acetone( / ;emo!e the acetone and attach the a$ hose to the lln% noPPle( Tu$n on the a$ pump "o$ about 1 mnute( Tu$n o the a$ pump and $emo!e the a$ hose "$om the lln% noPPle( ?leann% and d$yn% o" the measu$n% cell a"te$ each measu$ement s necessa$y " samples 'th de$ent chemcal composton a$e to be used( 3( Kensty measu$ements "o$ ult$apu$e 'ate$ /0O ethanol and absolute ethanol at the p$eset o o tempe$atu$e o" 20 ? and 30 ?: / Lct!ate the $e.u$ed method usn% the QMethodR so"t ,ey( / Select QKensty 20R o$ QKensty 30R at a p$eset o o tempe$atu$e o" 20 ? o$ 30 ? $espect!ely( / Ta,e a sample o" about 2(B ml "$om the bottle o" ult$apu$e 'ate$ p$o!ded usn% a sy$n%e and ensu$e that the$e a$e no a$ bubbles n the sample( /! Inject the sample th$ou%h the lln% noPPle nto the measu$n% cell o" the KML B000( /! bse$!e and ensu$e that the$e a$e no %as bubbles n the measu$n% cell and e#cess soluton eme$%es "$om the outlet hose connected to the 'aste bottle( /! I" %as bubbles a$e obse$!ed n the cell+ $epeat steps / to /!( /! L"te$ ensu$n% that the$e a$e no a$ bubbles n the cell+ p$ess Sta$tR "o$ densty measu$ement( Kensty $eadn% 'll appea$s on the sc$een a"te$
the system has e.ulb$ated( /! )hen Q?ondton: -$edete$mnedR appea$s on the sc$een+ a densty $eadn% o" B&decmal places 'll sho'( /# -$ess Q?ontnueR "o$ densty measu$ement "o$ the duplcate sample( /# I" the densty chec, "o$ the duplcate samples a$e + p$ess -$ntR to p$nt out a copy o" the $esult( /# ;epeat the p$ocedu$e "o$ densty measu$ement "o$ samples o" absolute ethanol( 4( Kensty measu$ements "o$ the 'ate$ðanol solutons: ;epeat the abo!e p$ocedu$e "o$ densty measu$ements "o$ the p$epa$ed samples o" 'ate$ðanol solutons 'th de$ent compostons( It s ad!sable to ca$$y out the measu$ement acco$dn% to the o$de$ "$om lo' to h%h ethanol concent$aton(
/-;@?LUTIS: 1( ?leann% and d$yn% o" the measu$n% cell a"te$ each measu$ement s necessa$y( 2( Samples "o$ densty measu$ements must be homo%eneous and "$ee o" %as bubbles(
>4
Re-%"- a+; Ca"%"a!#+-
>41 De+-!, Mea-%ree+-
Teera%re a 20
℃
: 20 ℃ : 1 atm
Tempe$atu$e -$essu$e U"ra%re (aer ;un
Kensty /%m>
1
0(9981D
2
0(9981E
3
0(99818
A6erae
04??817
Table 1 : Kensty o" ult$apu$e 'ate$ at 20
℃
A-#"%e E*a+#" ;un
Kensty /%m>
1
0(E8931
2
0(E893B
3
0(E893E
A6erae
0478?5
Table 2 : Kensty o" absolute ethanol at 20
℃
B!+ar, M!3%re @thanol /7olO
;un
Kensty /%m>
B
1
0(99109
2
0(99114
3
0(99119
A6erae
04??11
1
0(984EE
2
0(98484
3
0(98484
A6erae
04?882
1
0(9E908
2
0(9E910
3
0(9E90D
A6erae
04?7?08
1
0(9E3D0
2
0(9E3D4
3
0(9E3D4
A6erae
04?75>5
1
0(9D200
2
0(9D19E
3
0(9D29E
A6erae
04?>1??
1
0(94E2B
2
0(94E4B
3
0(94E43
A6erae
04?75>
10
1B
20
30
40
Table 3 : Kensty o" M#tu$e at 20 ℃
Teera%re a 50
Tempe$atu$e -$essu$e
℃
: 30 ℃ : 1 atm
U"ra#%re (aer ;un
Kensty /%m>
1
0(99BD2
2
0(99BBE
3
0(99BBB
A6erae
04??<<8
Table 4 : Kensty o" ult$apu$e 'ate$ at 30
℃
A-#"%e e*a+#" ;un
Kensty /%m>
1
0(E808D
2
0(E808D
3
0(E808D
A6erae
047808>
Table B : Kensty o" absolute ethanol at 30
℃
B!+ar, M!3%re @thanol /7olO
;un
Kensty /%m>
B
1
0(98EE4
2
0(98E14
3
0(98B2B
A6erae
04?8>71
1
0(98204
2
0(9819B
3
0(98190
A6erae
04?81?>
1
0(9EBE8
2
0(9EBD0
3
0(9EBB0
A6erae
04?7<>5
1
0(9D8D3
2
0(9D843
3
0(9D833
A6erae
04?>8>
1
0(9BD02
2
0(9BB98
3
0(9BB9D
A6erae
04?<
1
0(93948
2
0(9391E
3
0(93903
A6erae
04?5?25
10
1B
20
30
40
Table D : Kensty o" M#tu$e at 30
℃
>42 Ta%"ae; re-%"- r# -a"e a"%"a!#+ # Ta%"ae; Re-%"- #r 20 C
Sampl e no(
@than ol /7ol O
Kensty
1
B
0(9911
ρ /m>%
n1 /mol
n2 /mol
BB(B
0(90
∅
/m>mol B4(34
/d ∅ dn2 &0(40D
´ V 1
´ V 2
/m>mol
/m>mol
18(0B4
B3(9ED
41
1
2
10
0(9848 1B
BB(B 1
1(91
B3(90
&0(34B
18(0E0
B3(243
3
1B
0(9E90 82
BB(B 1
3(03
B3(B0
&0(2E8
18(094
B2(DB9
4
20
0(9E3D 29
BB(B 1
4(29
B3(20
&0(202
18(11B
B2(33B
B
30
0(9D19 99
BB(B 1
E(3D
B3(01
&0(01E
18(0DB
B2(882
D
40
0(94E3 D0
BB(B 1
11(4 4
B3(32
0(229
1E(B09
BB(941
o Table E: Tabulated ;esults "o$ calculatons at 20 ?
# Ta%"ae; Re-%"- #r 50 C
´ V 1
´ V 2
/m>mol
/m>mol
&0(E8B
18(10D
BD(0DD
B4(28
&0(DB9
18(13E
B3(03B
3(00
B4(0D
&0(B20
18(1E9
B2(494
BB(B 1
4(2D
B4(18
&0(3D4
18(214
B2(D29
0(9BB9 9
BB(B 1
E(30
B3(89
0(01B
18(081
B3(998
0(9392 3
BB(B 1
11(3 B
B4(3D
0(B20
1D(889
D0(2B8
Sampl e no(
@than ol /7ol O
Kenst y ρ /m>%
n1 /mol
n2 /mol
1
B
0(98DE 1
BB(B 1
0(90
BD(EE
2
10
0(9819 D
BB(B 1
1(89
3
1B
0(9EBD 3
BB(B 1
4
20
0(9D84 D
B
30
D
40
∅
/m>mol
/d ∅ dn2
o Table 8: Tabulated ;esults "o$ calculatons at 30 ?
>45 Sa"e Ca"%"a!#+- a+; Der!6a!#+Sa"e Ca"%"a!#+- #r E*a+#" @ < 6#" a T @ 20C a+; P @ 1a: C1 5 0(9981E%ml * C2 5 0(E893D%ml * a!e$a%e C 5 0(99114%ml 1000
n1 5
5
w1
7t 5 / 5/
1000
1000
5 BB(B1 mol
18.015
!olume o" 'ate$ used # 2Bml
ρ 1 1000
0.99817
23(EBml # 2Bml
5 10B4(BD ml n2 5 / ρ # 7t V 1000 )2 5 / 0(99114%ml # 104B(BDml V 1000% 4D(0E0 %mol 5 0(90 mol 5
∅
1000
&
0.90
1
F )2 V /
ρ
/
1000
/
n2
0.99114 −0.99817 0.99817
ρ − ρ 1 ρ1
¿
5
1 0.99114
F 4D(0E0
5 B4(34 mlmol T@: L"te$ attann% the !alues o" ∅ "o$ all concent$aton le!els+ the %$aphs o" ∅ !s n2 as seen n % 2 belo' can be plotted "o$ both tempe$atu$es( ´
V 1
5 /
0.90
1000
ρ 1 n1
2
V/
n2 n
1
/
d∅ A 5 / d n2
1000
0.998167 x 55.51
V/
2
55.51
´ V 5 2
/&0(40D 5 18(0B4 mlmol
∅
6 n2 /
d∅ 5 B4(34 6 0(90/&0(40D 5 B3(9ED d n2
mlmol A
d∅ s dete$mned "$om the slope o" the %$aph n % 2 d n2
belo' by de$entaton o" the "uncton at the !a$ous ponts( The pa$tal mola$ !olume %$aphs can then be plotted a%anst n2 a"te$ attann% the !a$ous $espect!e pa$tal mola$ !olumes "o$ the t'o substances+ to %!e a clea$e$ $elaton o" pa$tal mola$ !olumes o" 'ate$ 'th tempe$atu$e and amount o" solute as seen n % 3 belo'(
>45 Gra*- # 6ar!#%- re"a!#+-*!- "#e; The %u$es belo' sho's the %$aphs o" absolute mola$ !olumes and pa$tal mola$ !olmues a%anst n2 + the amount o" solute(
Gra1* # A11are+ M#"ar $#"%&e # S#"%e9C '&L/&#". a8a!+- +2 '&#". B8 BE BD BB
A11are+ M#"ar $#"%&e # S#"%e 9C '&L/&#".
B4 B3 B2 B1 0
B 10 1B
+2'&#". T520
T530
%u$e 2: G$aphs o" appa$ent mola$ !olumes o" solute at both tempe$atu$es
Gra* # $1 a+; $2 a8a!+- +2 #r Te&era%re @ 20BC a+; 50BC E0 D0 B0 40
$1/$2 30 20 10 0 0
2
4
D
8
10
12
14
+2 / &#" 71 W T520
72 W T520
71 W T530
72 W T530
%u$e 3: G$aphs o" pa$tal mola$ !olumes a%anst amount o" solute at both tempe$atu$es 74
D!-%--!#+ 741 Re-%"- !+ re"a!#+ # G!-)D%*e e%a!#+ The Gbbs V Kuhem e.uaton s dened as: X#1d7 5 0 at constant T and -( Jased on the lnea$ty o" %$aphs o" 71 and 72 a%anst n2 as seen n %(3+ t s %ene$ally a Nat st$a%ht lne that s pa$allel to the # a#s( Ths the$e"o$e mples that 7 does not chan%e $e%a$dless o" n2+ ma,n% t a constant despte the amount o" substance n the m#tu$e( The$e"o$e d7 s al'ays 0+ sats"yn% the Gbbs & Kuhem e.uaton( Ho'e!e$+ by obse$!aton o" the $esults o" %$aphs abo!e+ the %ene$al shape o" the %$aphs o" 7 at 30 o? a$e sl%htly cu$!ed especally so "o$ the 72 %$aph( Ths ndcates that t s the e#pe$ment 'as not pe$"ect+ manly due to some possble sou$ces o" e$$o$ "o$ the study( the$'se+ t can be obse$!ed that the Gbbs V Kuhem e.uaton has been satsed(
742 Ee- # eera%re & re--%re #+ ar!a" #"ar 6#"%eLlthou%h ns%ncant+ t can be obse$!ed n %( 3 that
the pa$tal mola$ !olumes nc$eases as tempe$atu$e nc$eases( Ths s the case "o$ JTH substances o" the m#tu$e+ thus bac,n% up the assumpton that t holds t$ue "o$ all pa$tal mola$ !olumes o" all substances n %ene$al( Ths s due to the "act o" mo$e ene$%y s suppled to the molecules and hence they a$e able to !b$ate mo$e at h%he$ tempe$atu$e+ as a $esults o" ths mo$e !%o$ous !b$aton+ the !olume occuped by the molecules nc$eases as tempe$atu$e nc$eases( Ho'e!e$+ ths study s not conclus!e enou%h to "ully bac, up the hypothess( The chan%es to the pa$tal mola$ !olumes a$e mnmal "o$ both substances n ths study( Ths s due to both substances ben% n l.ud state+ thus enabln% us to t$eat t as %ood as ncomp$essble 'th the mnmal chan%es n densty and pa$tal mola$ !olumes( n the othe$ hand+ the eect o" p$essu$e on pa$tal mola$ !olumes cannot be dete$mned "o$ ths e#pe$ment o$ study( The ndependent !a$able s only the tempe$atu$e 'hle assumn% constant p$essu$e+ thus ma,n% t nconclus!e to ndcate the eects o" p$essu$e on pa$tal mola$ !olumes( Ho'e!e$+ t can be assumed that p$essu$e has an eect on the pa$tal mola$ !olumes as nc$easn% p$essu$e $esults n nc$easn% "o$ces on the molecules+ thus aectn% the appa$ent and pa$tal mola$ !olumes o" the substances( Ths s because the pa$tal mola$ !olumes a$e dependent on the amount o" moles o" ult$apu$e 'ate$ and ethanol+ as can be seen n the sample calculatons( Ho'e!e$+ snce amount o" moles nc$eases 'th nc$easn% p$essu$e at constant total !olume+ calculated pa$tal mola$ !olumes o" nd!dual component 'll dec$ease 'th nc$easn% p$essu$e( The eects o" p$essu$e on pa$tal mola$ !olumes a$e small and ne%l%ble n ths e#pe$ment as the m#tu$e s n the l.ud phase and can be assumed to be ncomp$essble( Ho'e!e$+ the eects o" p$essu$e on pa$tal mola$ !olumes o" %aseous m#tu$es 'll be s%ncant(
745 P#--!"e -#%re- # err#r & re#e+;a!#+-
>,e any e#pe$ment+ ths study s based on an e#pe$ment that s not pe$"ect and has a tendency to p$oduce e#pe$mental $esults that de!ate "$om t$ue !alues( Jelo' a$e the possble sou$ces o" e$$o$ "o$ the de!atons( 1( Jassassumptons used "o$ calculatons In the study+ 'hen de$!n% the pa$tal mola$ !olumes+ 'e used the mass o" sol!ent to be #ed at 1000% "o$ con!enence pu$poses 'hen n actual "act+ 'e a$e actually chan%n% the numbe$ o" molesmass o" sol!ent used+ 'hen 'e p$epa$e the solutons+ total !olume o" m#tu$e s #ed at 2Bml( The$e"o$e+ 'e a$e al$eady assumn% that the pa$tal mola$ !olume o" substances does not chan%e based on total amount o" m#tu$e but the "$acton o" substances used( The$e"o$e+ t s possble that e$$o$s may occu$ as 'e dd not # the mass o" the sol!ent du$n% the e#pe$ment+ but #ed the !olume o" m#tu$e nstead( L $ecommendaton 'ould be to test ths assumpton so that ou$ $esults ha!e a st$on%e$ "oundaton( In addton+ t 'as assumed n the calculatons that the appa$ent mola$ !olume o" the ult$apu$e 'ate$ $emans unchan%ed "o$ the smplcty o" calculatons( Ths thus+ s a possble sou$ce o" e$$o$+ basn% calculatons on assumptons(
2( @!apo$aton o" !olatle substances The absolute ethanol used n the study s $elat!ely a !olatle l.ud( The$e"o$e+ 'hen p$epa$n% the solutons and measu$n% the$ m#tu$e denstes+ ethanol m%ht ha!e !apo$se+ thus aectn% the mole "$acton o" the substances n the m#tu$e( Ths 'ould thus aect the measu$ements o" denstes o" the m#tu$e+ thus aectn% the 'hole $esult o" the e#pe$ment especally snce the slope o" the %$aphs a$e senst!e to the chan%es n appa$ent mola$ !olumes( L su%%eston
'ould be to put a ld o!e$ the bea,e$s contann% the solutons be"o$e measu$n% the densty o" the m#tu$e should t ta,e a 'hle to use the denstomete$( Lnothe$ 'ay to a!od ths stuaton 'ould be to measu$e the densty mmedately a"te$ p$epa$n% the solutons+ thus mnmsn% the e$$o$ o" !apo$saton( 3( acto$s aectn% densty measu$ements a$ bubbles -ossble e$$o$s may a$se 'hen measu$n% the densttes o" the m#tu$essolutons( @specally so "o$ the denstomete$( The machne s used consecut!ely "o$ all the solutons 'hch a$e at de$ent concet$aton le!els o" ethanol thus emphassn% on the mpo$tance o" cleann% p$ocess o" the cell( Sl%ht mpu$tes o" p$e!ously used solutons could $ende$ chan%es n concent$aton le!els o" the ntended m#tu$e 'hch densty s to be measu$ed( Ths 'ould thus aect the $eadn%s o" the denstes+ thus causn% a chan o" eect n the e$$o$ made to the calculatons( Llso+ one man conce$n and dsad!anta%e o" the pump o" the denstomete$ and njecton o" solutons a$e the possble a$ bubbles( L$ has a much lo'e$ densty than any l.ud+ thus ths 'ould aect the $eadn%s s%ncantly( ne $ecommendaton 'ould be to use a de$ent app$oach o" measu$n% denstes alon%sde ths method( Lddtonal measu$ement o" denstes o" same solutons usn% the pycnomete$ 1+ "o$ e#ample+ can $educe e$$o$ o" a$ bubbles and thus mp$o!e accu$acy o" $esults( 4( Techn.ues to p$epa$e solutons Techn.ues due to human e$$o$ 'hen measu$n% the solutons usn% common appa$atus m%ht cause $esults to de!ate sl%htly "$om t$ue !alues( Measu$ement o" !olumes usn% a bu$ette "o$ e#ample m%ht ncu$ pa$alle# e$$o$s+ thus aectn% e#act o$ t$ue concent$aton le!els o" m#tu$es 'hch denstes a$e to be measu$ed subse.uently( L st$on% su%%eston 'ould be to nc$ease the numbe$ o" samples o" solutons o" the same concent$aton le!el n 'hch the
measu$ement o" denstes s ta,en "$om( Ths 'ould substantally $educe the possblty o" human e$$o$ aectn% the $esults+ thus mp$o!n% accu$acy o" e#pe$mental !alues( B( luctuatn% and non un"o$m tempe$atu$es -ossblty o" Nuctuatn% tempe$atu$es may also ncu$ e$$o$ o" pa$tal mola$ !olumes( Llthou%h chan%es n pa$tal mola$ !olumes a$e not s%ncant n ths case 'th chan%es o" tempe$atu$e as seen n the $esults+ mantann% a constant tempe$atu$e s dYcult and tme s needed to $each a steady stead "o$ ene$%y balance( Llso+ t s possble that tempe$atu$e ac$oss the sample s not un"o$m+ thus possbly aectn% e#pe$mental !alues o" the denstes( Ho'e!e$+ the de!atons may be ne%l%ble as denstomete$s a$e usually eYcent n mantann% solutons at tempe$atu$es(
?4
C#+"%-!#+ In concluson+ the t'o"old am o" the study has been met to a la$%e e#tent( The study has %!en a bette$ unde$standn% o" pa$tal mola$ p$ope$tes+ such as ts nt$nsc p$ope$ty as sho'n by the %$aphs n %u$e 3 abo!e( In addton to that+ n the study+ 'e 'e$e able to dete$mne the pa$tal mola$ !olumes o" both the substances n the m#tu$e usn% a the smple+ "ast and eect!e app$oach by >e's Z ;andall n yeldn% "ast and post!e $esults o" pa$tal mola$ !olumes( $om the study+ t can also be concluded that the tempe$atu$e o" the m#tu$e aects the pa$tal mola$ !olumes o" ts consttuents( Ho'e!e$+ othe$ methods and studes also ha!e to be done to suppo$t ths study due to the !a$ous possble sou$ces o" e$$o$ and assumptons used as a bass o" the calculaton and de$!atons o" the pa$tal mola$ !olumes o" both ult$apu$e 'ate$ and absolute ethanol( Llso+ "$om the study+ 'e cannot dete$mne the $elatonshp o" pa$tal mola$ !olumes 'th the$modynamc pa$amete$s othe$ than tempe$atu$e+ l,e p$essu$e "o$ e#ample+ as only tempe$atu$e and concent$aton le!els o" solute a$e !a$ables(
104
Reere+e-
1 Measu$ement o" -a$tal Mola$ 7olumes + ;et$e!ed 18 Sept+ 2014 "$om http:n"ohost(nmt(edu[jalt%-a$t7ol(pd" 2 -a$tal Mola$ -$ope$tes dentons + ;et$!ed 18 Sept+ 2014+ "$om http:'''(le(ac(u,chemst$ythe$modynamcspd"s3 000Topc2B8B(pd" 3
Molecula$ theo$y o" pa$tal mola$ !olume and ts applcatons to bomolecula$ systems + ;et$!ed 18 Sept+ 2014+ "$om http:'''(cmp(l!!(uajou$nalPb$ny,(B1004a$t04( pd"
114
Ae+;!3
1141 Par!a" M#"ar Pr#er!e)hen a m#tu$e s "o$med "$om m#n% se!e$al pu$e components+ the the$modynamc p$ope$tes o" nd!dual component n the m#tu$e a$e %ene$ally e#p$essed n te$ms o" pa$tal mola$ p$ope$tes /Mi ( -a$tal mola$ p$ope$tes such as pa$tal mola$ !olumeV i + pa$tal mola$ enthalpy
Hi
+ pa$tal mola$ Gbbs ene$%y
Gi
+ a$e ntens!e
p$ope$tes based on unt mole and a$e ndependent o" the total amount o" the m#tu$e( -a$tal mola$ p$ope$ty M i s a measu$e o" a cont$buton o" a component to the total t p$ope$ty M o" the m#tu$e and s dened as "ollo's: Mi
t 5 /\M \n T+ -+ nj/j] /1
Mi
t measu$es the chan%e n total p$ope$ty M 'th chan%e n
n 'hen T+ - and composton o" all othe$ components e#cept component a$e ,ept constant( >,e 'se+ pa$tal mola$ !olumeV i + pa$tal mola$ enthalpy Hi + and pa$tal mola$ Gbbs ene$%yGi + a$e dened as: t t 5 /\7 \n T+-+nj/j]H 5 /\H \n T+-+nj/j]G 5 ^ 5 i i t /\G \n T+-+nj/j] V i
-a$tal mola$ p$ope$tes a$e mpo$tant p$ope$tes and used e#tens!ely n the analyss o" p$ocesses and p$ocess e.upment n chemcal en%nee$n%(
1142 P,+#eer
1
The pycnomete$ s $st calb$ated a%anst )ate$( The pycnomete$ s cleaned+ d$ed and 'e%hed empty( Then t s lled 'th )ate$( Usn% the densty o" )ate$ at the measu$n% tempe$atu$e and the mass o" the )ate$ $e.u$ed to ll the pycnomete$+ the !olume o" the pycnomete$ can be calculated( The pycnomete$ s then lled 'th the soluton 'hose densty s to be dete$mned and 'e%hed( Ths mass+ alon% 'th the calb$aton !olume+ %!es us the des$ed densty measu$ement(
%u$e 4: Ln ma%e o" the pycnomete$ 1
