J. Chem. Eng. Data 1983, 28, 113-119
113
Total-Pressure Vapor-Liquid Equilibrium Data for Binary Systems of Nitromethane with Ethyl Acetate, Acetonitrile, and Acetone Jagjlt R. Khurma, 01 Muthu, Sarat Munjal, and Buford D. Smlth” Thermodynamics Research Laboratory, Washington University, St. Louis, Missouri 63 130
Table I. Chemicals Used
Total-pressure vapor-liquid equlilbrlum (VLE) data are reported at approxlmately 298, 348, and 398 K for each of three nitromethane binarles with ethyl acetate, acetonitrile, and acetone as the other components. The experimental PTx data were reduced to yI, y I , and G E values by both the Mlxon-Gumowskl-Carpenter and the Barker methods, but only the Mlxon et al. results are reported in their entirety. Seven GE correlations were tested in the Barker data reduction wlth the flve-constant Redllch-Kister equation glving the best results. The effect of the equatlon of state used to estimate the vapor-phase fugaclty coefflclents was Investigated.
stated purity, %
component
vendor
ethyl acetate acetonitrile acetone nitromethane
Burdick and Jackson Burdick and Jackson Burdick and Jackson Mallinckrodt
E T H Y L R C E T 9 T E (11
+
99.9 99.9t 99.9+
99.9
N I T R O M E T Y R N E (21
R 298.16 K E 3il8.22 K C 398.17 K
Introductlon This paper presents total-pressure vapor-liquid equilibrium data for three systems with nitromethane as the common component. The other components are ethyl acetate, acetonitrile, and acetone. Previous papers have reported data for nitromethane with 1-chlorobutane ( 7 ) and with chlorobenzene (2). A subsequent paper will cover data with methanol and ethanol. The apparatus and techniques used to measure all of these data have been described previously along with the defining equation for the activity coefficient and the standard state used (3).
Chemicals Used The sources and purities of the chemicals used are listed in Table I. Activated molecular sieves (either 3A or 4A) were put into the chemical containers as they were received. Just prior to being loaded into the VLE cells, each chemical was poured into a distillation flask and distilled through a Vigreux column (25-mm 0.d. and 470 mm long). The first and last portions of each distillate were discarded. The retained portions were caught in amber bottles and back-flushed with dry nitrogen for transfer to the cell-loading operation. The stated purities of the chemicals were verified with gas-liquid chromatography at this point. None of the compounds exhibited any degradation during the VLE measurements. The cell pressures were stable with respect to time, and all liquids were perfectly clear when removed from the cells at the end of the last isotherm.
Experimental Data Tables 11-IV present the experimental PTx data. The “smooth” pressure values reported are from the least-squares cubic splined fits used to provide the evenly spaced values required by the finitedifference Mixon-Gumowski-Carpenter method (4) for the reduction of PTx data. Figures 1-3 show the experimental data in terms of the pressure deviation P, from Raoult’s law P, = P
-
[P2’
+ x,(P,’ - f 2 ’ ) ]
0021-9568/83/1728-0113$01.50/0
00
0.20
0.110
0.60
0.80
1.00
Xl
Flgure 1. Devlation from Raoult’s law for the ethyl acetate (1) nitromethane (2) system.
+
where P is the experimental mixture pressure and the P,‘ values are the pure-component vapor pressures. The deviation pressure plot emphasizes the scatter more than a P vs. x plot but does not show whether or not an azeotrope exists. The point symbols in Figures 1-3 denote the experimental data points exactly. The curves approximate-sometimes not very closely-the splined fits of those data points. Closely spaced points from the splined fits were fed to the plotting program which then plotted its fit of the input values. The plotting-program fits are often not very good, particularly for a system such as the one in Figure 2. Nevertheless, the curves do help illustrate the behavior and the scatter of the experimental data points. Tables 11-IV show how well the splined fits (smooth values) actually do fit the experimental data points. The ethyl acetate system (Figure 1) exhibited only positive deviations from Raoult’s law, while the acetone system (Figure 0 1983 American Chemical Society
114 Journal of Chemical and Engineering Data, Vol. 28, No. 1, 1983
Table 11. Experimental P vs.x, Values for the Ethyl Acetate (1) t Nitromethane (2) System
.oooo
4.790 5.3 0
0360 .0802 1 429 2007 2990 3892 .4937 .5933 6952 7795 -8404 .9124 .9 465 1.0000
4.790 5.310 5.858
5.848
4:7.837 505:
6.529 7.051 7.832 8.501 9 224 9.894 10.588
8.496 9.223 9.897 10.585 1 e163 1 e581 1 e070 12.298 12.647
1
ft:J$P
12-06? 12.304 12 645
.0000
't
.0470 .O949 1462 ,2147 .3010 .4094 .5U63 bOLl ,6941 ,7513 ,8612 9253 e9bl8 1. G O O 0
.
42.29 45 e 84 49 59 54 e 14 57.92 63 38 68.05 73.06 77.55 82.11 85.78 88-40 91.48 92.95 95 06
e 0000 e0359 .0802
:1:2989 s:
3890 4936 e5931 6951 .7794 .a404 9124 e 9465 1.0000 e a
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42.28 45.85 49.58 54.17 57 e 88 63.42 68.04 73.05 77.58 82.09 85.78 88.43 91.49 92.91 95.08
245.09 $59.02
201.13 214.24 227.98 245.04 259. Ob
297.6 316.3 332.9 349.3 362.3 37 4 38!!:1 387.1 394.4
297.6 316.3 333.0 349.2 362.2 371.5 382.1 387.0 394.5
$?i:jg 227.94
.0359 -0801 e1427 .2004 2987 e3887 -4933 e5929
80.3
iilif
e9123 e9465 1.0000
280.3
,785
5,158
5.501
5 .d59
6 335
,935 7. b a i 8.363 ,>. 025 b
9.660 13.312 10 J7il 1 1 336
4
11.594 ii.a6i
9CETOhITRILE 1 1 1
+
NITSOMETHQNE (21
aA 23118. 3 8 .,17 9 K c 3 3 7 . i 9 i(
R 298.16 K a 3ua. 1 7 K c 398 1 7 K
O u m i
a
L
L
x
L
i
W
a G
O
~
I
a i 0
I
1
0.00
,
0.20
Ld/ t
I
0.110
0.60
0.80
j
10
i
9.00
I
0.20
I
I
e . 40
0.60
I
0.80
t
1 00
XI Flguro 2. Deviatlon from Raoult's law for the acetonkrile (1) methane (2) system.
+- nitro-
Figure 3. Deviatlon from Raoult's law for the acetone (1) -I-nitromethane (2) system.
Journal of Chemical and Engineering Data, Vol. 28, No. 1, 1983 115
Table IV. Experimental P vs. x Values for the Acetone (1)
+ Nitromethane (2) System
.-- - ---- -- -. 195.34 :P?::t 213.69 23 1.47 231 - 5 0 .
b----------.
4.789 5.815 6 798 7.807 9.685 11.147
:88PP 08 19
\:!iE:
20.025 22.511 25.688 27.157 2 8.54 29.77 30.88
Table V. Calculated Data for the Ethyl Acetate (1) L I Q U I D MOLAR VOLUMES,
004!1 09 17 .I242 a2027 -2631 e 3726 .4909 6078 6981 -9113 96 34 -9126 e 9 5 17 1.0000 s
1244 m2030 ,2635 .3731 04914 6085 s6986 e8117 8638 e9128 .95 78 1,0000
CC/HOLl
98.450
VL(2)
MIXTURE FUGACITY COfFF I C IEN,TS
a9476 e9969 e9964 e9960 ~9956 e9953 a9949 e9946 e9942 e9939 e9935
..
X l 0000
1000 .2000 e 3000 e 4000 e 5000 e 6000 e 7000 e 8000 e9000 I . 0000
T TAL PRESSURE i!xPTLe
42.285
;:A63.478 +
68.579 73.345
iI:88!4 86.682
90.966 95.083
KPA CALCe
42.285
68.579 73.345 77.884 82 e 305 86.682 90.966 95 e 083
L I Q U I D MOLAR VOLUflES,
XL
00000 e 1000 a2000 a3000 ~4000 5000 e6000 a 7000 08000 e9000 le0000
CC/HOLt
TOTAL PRESSURE KPA CALCe
$8!!‘i;O
233e655 258.961 280.534 299.727
$$i:!iJ 350.043
365.407 380.329 394.469
VL(1)
201.130 233.648 258.955 280.529 299.725 3 7.476 3b4. 57 350.643 365.401 380.330 394.469
=
105.858
1 a9860 e9830 -9807 e9788 e9771 e9755 09739 b9725 a97 0 e9646 e9602
VL(1) *
1 e0800
f:8% t:8X VL(21
249.53
28’) .O 309 e 1
157.3
410.q
466.9 ‘510.0 567.0 591 e 8 619.3 642.7 664.4
C O E I ~c
1
-9546 e9363 e9319 a9279
Y l
115.503
VL(2) =
Ih2 s
e9614 e9552 e9505 e9464 e9428 e9395 e9364 e9307 9280 :9255
I e 6000
1 e 0080
1:8;8 1 e0841 l e
1139
1 e 1431 e2895
EXCESS GIBBS FUNCTION, J/MOLE 0.00
96.68 157.09 188.25
65.65 133.49 94 e 93 5 94
A:
00
57.395 EXCESS
0000 e2474 ,3977 e 5077 e 5989 e6785 a7506 a8179 e8817 418 le0000
HIXTURE F U ACITY
COEFFIC!ENTS
1.i156 1.3742 le2319 1.1369
2 e9883 .9858 .9840 -9825 e9811 a9798 e9786 a9774 m9762 e9751 a9740
3) was entirely a negative deviation system at the three temperatures studied. From the trends shown, the ethyl acetate system would probably show negative deviations at lower temperatures, while the acetone system would probably become a positive deviation system. As those two systems pass from one kind of deviation to the other kind, there would be a temperature range in which they would exhibit mixed deviations such as those shown in Figure 2 for acetonitrile. At 298.15 K, the acetonitrile nitromethane system shows
+
249 49 282.9 309 2 157.5 410.8 465 9 510.1 567.0 593.8 61 9.3 642.7 664.4
53.988
ACTIV!TY
e9580 a9975 e9971 e9967 e9964 e9962 e9959 e9956 e9953 e9951 e9948
flIXTURE FUGACITY COE FF I C I EN1S
$#:E 63.476
,-
+ Nitromethane (2) System at 298.16, 348.22, and 398.17 K
VL(1I
L I Q U I D HOLAR VOLUflES, CC/HOL8
-
I--------
000 0
e
.
A C T I V I TY COEFF I C IENTS
1
1.5928 le3522 le2269 1.1434 1.0908 1.0555 1.0314
f:8b8
.
e0028
1 0000
2 1.0000 1 e 0079
1:8Gi 1 l!i#
e0759 1050 e2333
1 e 3115
g1b05
FUNCT I ON p J/HOLE
0.00
1%: 198 213.68
227.66 222.75 201 e 86 167.45 22.37 67e86 0.00
61.451 EXCESS
.
Y1 0000 e2139 e 3565 e4672 5603 e6436 7204
:a9321 x963
1.0000
i .oooo
ACTIVITY COEFFIC ENTS
1
1 e 5520 1 1.2i56 .3 54 le1434 e0586 e0345 0825
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GIBBS
FUNCTION, J/HOLE
0m00
M:5679
231.98
1 e 0972
t:
%$t?S:Q’:
M: 140.24
77.49 0.00
positive deviations at both ends of the composition range but the P, curve sags in the middle below the Raoult’s law iine. I t becomes even more “positive” at each end at 348.17 K but the sag in the middle has become more pronounced. At 398.17 K the positive deviation at low x , values is stronger but now the system shows only negative deviations in the middle and high x , regions. None of the three systems exhibited an azeotrope at any temperature studied.
116 Journal of Chemical and Engineering Data, Vol. 28,No. 1, 1983 Table VI. Calculated Data for the Acetonitrile (1) t Nitromethane (2) System at 298.15, 348.17, and 398.17 K
L I L J U I D MJLAK V U L U M E S i L C / M O L : TJTAL PR€SSURE, KPA E XPTL CALC u.705 4.705 5.538 5.53J 6.234 6.234 .2000 b.925 6.925 3000 400d 7.016 7.616 500U 3.313 3.3 1 3 6000 9.316 9.016 .7000 9.725 9, 7 2 5 10.440 10.443 .auoo 9000 11.156 11.156 1. 00u0 11.861 11. d 6 1 L I )U10 MilLAS V O L U M E S , C C / H O L :
x1
.0050 .la00
=
VL(1)
52.824
VL(2) =
MIXTURE FUGACITY CJFFF I C I E N I S
,9879 .9975 ,9972 e9969 . 9 w ,9963 a9963 ,9957 e9953 e9950 ,9947 VL(1)
.9$80 .9977 a9974 ,9971 ,9960 e9965 e9962 ,9959 ,9956 ,9954 ,9951 56.417
MIXTURE FUGACITY C U E F F I C It N! 5 1 L ,9875 9883 .3a63 9a72 ,9861 ,9852 >340 9850 9839 .9a23 .Yd17 9828 e9805 9 8 17 .9 793 .9ao6 ,9781 .9795 e7769 9783 3757 9772
53.942 ACTIV!TY
Y1
.oooo
,2198 .mi4 ,5114 6186 7388 7855 ,8512 9080 -9572 1.0000 VL(2) *
C O E F F I C !ENTS
.oLooo
1.8893 1.0295 1.0051 0.9976 0,9951 0.9952 0.9965
1.0027 1 0066 1.0090 1.0103 1.0102 1 0086 1 0055 1.0005 0.9958 1.0225
0":8%!# 1 0006
1.0000 57.211
EXCESS G I BBS FUNCTIONe J/HOLE 0.00 13.30 15.64 13.85 10.45 6.65 3.26
0.80 0.38 0.00
-0.27
EXCESS
GIBBS
'
X I .0300 .loo0 ,2300 3000 4000 5000 .6000 7009
.
,8003 YO00 1.0000
1.;ITAL PRE SSUKE, KPA EXPTL C4LC.
42.186 46.274 53.1 40 54.U56 58.016 62.006 66.014 70&5 I 74.159
78.337
82.373
42.1 a6 46.272 50.139 54.055 58.0 15 62.005 b6.014 70.057 74, I 5a 78.336 u2.373
L I P U I D M J L A l i VOLUMES,
X I
.0000
.lo00 ,2330 3003 4000 e5300 bdS0 .7000 e000 9000 1.0000
.
iC/MOL:
T J T A L PRC SSURE KPA EXPTL CALL. 200 7 92 200. 792 215.142 215.135 228.069 228. J 7 6 241.134 241.140 254.35d 254.363 267.773 267.774 231.397
