J. Chem. Eng. Data 1989, 34, 5-7
As
standard entropy change of reaction, cabmol-’OK-’ stoichiometric coefficient of component i fugacity coefficient of component i
O
VI
co,
Subscripts E ETBE Et ethanol e equilibrium f formation 9 vapor phase I lsobutene i component N nitrogen RWISttry NO. ETBE, 637-92-3;(CH&C=CHz,
115-11-7;CHSCHZOH,
64-17-5.
Literature Cited Iborra, M.; Izqulerdo, J. F.; Tejero, J.; Cunlll, F. CHEMTECH 1988, 78,
120-2.
Leum, L. N.; Macuga, J.; Kreps, S. I. U.S. Patent 2480940, 1949; Chem. Abstr. 1950,44, 652. Macho, V.; Kavala, M.; Okresa, M.; Pollevka, M. Rope Uhlie 1882,24, 1107
&;atella, P.; Malorano. 0.; Schwarz, P.; Valtorta, L. Braz. Pedido PI BR 8204380,1983;Chem. Abstr. 1983. 98, 197605. Lislchkln, G. V.; KWyavtsev, G. V.; Bemadyuk, S. 2. Zh. Vses. Khlm. Ova 1983,28, 712-13. ChlMs. W. V. U.S. Patent 4440983. 1984;Chem. Abstr. 1984, 700,
209183.
5
(7) Staines, M. S.U.K. Patent Appl. GB. 2123411,1984;Chem. Abstr. 1984, 700, 177611. (8) Macho, V.; Vesely. V.; Baxa, J.; Truba, K.; Kavala, M.; Kordik, J.; Jureckous, E. Czech. Patent CS229708, 1986; Chem. Abstr. 1988, 705, 136893. (9) Jones, E. M., Jr. US. Patent 4504887,1985; Chem. Abstr. 1985, 702, 223213. (10) Setinek, K.; Prokop. 2.; Kraus, M.; Zltny, 2. Chem. Rum. 1977,2 7 , 451-5. (11) Fattore, V.; Massi Mauri. M.; Orlani. 0.; Paret, 0. Hydrocarbon Process. 1981,60, 101-8. (12) Cunill, F.; TeJero, J.; Izqulerdo. J. F. Appl. Catal. 1987,34. 341-51. (13) Horsely, L. H. I n Azeotropic Data III; GouM, R. F., Ed.; Advances in Chemistry Serbs 118;American Chemlcal Soclety: Washington DC, 1973;p 138. (14) Evans, T. W.; Edlund, K. R. Ind. €ng. Chem. 1938,2 8 , 1188-8. (15) Izquierdo, J. F.; F e r 6 J.; Cunlll, F. Afinidad lB87,44. 419-23. (18)Tejero, J.; Cunlll. F.; Izqulerdo, J. F. Ind. Eng. Chem. Res. 1988,27. 338-43. (17)Tejero, J. Ph.D. Thesis. University of Barcelona, 1986. (18) ReM, R. C.; Prausnitz, J. M.; Sl?erwood, T. K. The Roperties of Gases and Liqukjs, 3rd ed.; McGraw-HIII: New York. 1977;Chapters 5 and 7. (19) Hougen, 0.A.; Watson, K. M.; Ragatz, R. A. Chemlcal Process Princlples Part 11, Thermodynamics, 2nd ed.; Wiley: New York, 1966; Chapter 25. (20)Fenwick, J. 0.; Harrop, D.; Head, A. J. J. Chem. Thennodyn. 1975, 7 , 943-54. (21) Perry, R. H.; Chilton, C. H., Eds.; ChemicalEnglneer’s /-/andboo&,5th ed.: McGraw-Hill: New York. 1973:Chaoter 4. (22) Park, S. w.; Hlmmelblau, D.’M. A I C h E j . 1980,26, 188-70. (23) Hawes, R. W.; Kabel, R. L. AIChE J. 1988, 74, 608-11. Recelved for review November 17,1987. Revlsed June 7, 1988. Accepted July 14, 1988.
Volumetric and Viscometric Studies of Binary Liquid Mixtures S. C. Agnihotri and Om Prakash” Chemical Laboratories, University of Allahabad, Allahabad 2 1 1 002, India
Density and viscoslty measurements at 30 OC for the mixtures of N-methyianillne 1,1,2,2-tetrachloroethane and N-methylanlllne dimethyl suifoxlde over the entire range of composttlon were used to calculate excess volume Vel excess vlscosity AvE, and excess molar Glbbs free energy of activation of flow S(AG*). Grunberg and Nlssan’s parameter d was also calculated. The excess properties have been attrlbuted to the molecular lnteractlon between the dissimliar molecules of the liquid mixtures.
+
+
Introduction I n binary liquid mixtures, the molecular interaction between dissimilar molecules is influenced by structural arrangement along with shape and size of the molecules. The study of Fort and Moore ( I ) has revealed that the positive deviation in viscosity from ideal behavior arises from strong molecular interaction between dissimilar molecules, but if It is found to be negative, the dispersion forces are likely to dominate. The variation of viscosity and molar volume with changing composition of the mixtures has been Investigated by various workers (2-5). This paper deals with our investigations of thermodynamic and transport properties of binary liquid mixtures and is in continuation of our previous studies (6-8). From the experimental results of densities and viscosities for the systems 1 , i ,2,24etrachloroethane and N-methylN-methylaniline aniline i- dimethyl sulfoxide (DMSO) at 30 OC, excess molar volume VE, excess viscosity AqE, excess molar Gibbs free energy of actbation of flow 6(AG *), and Grunberg and Nissan’s parameter d have been computed.
+
Experimental Section
Materials. N-Methylaniline(Kotch-light), dimethyl sulfoxide (Riedel), and 1,i ,2,2-tetrachloroethane(Riedel) were used after purification by the standard methods described by Weissberger (9).The calculated volumes of liquids were added to get mixtures of different known compositions. The mixtures were kept for 2 h, and then they were used for density and viscosity measurements. DensHy Measurements. The densities of pure liquids and mixtures were determined by a double-armed pycnometer having capillaries of narrow bore provided wlth well-fitting glass stoppers in order to avoid changes in composition due to evaporation. The pycnometer was calibrated with double-distilled water and benzene. The accuracy in density was
f0.01%. VlscosHy Measurements. Viscosities were determined by a viscometer similar to the Cannon-Ubbehlohde viscometer, calibrated with benzene and toluene, and the accuracy in viscosity was f0.005 cP. Calculatlons Molar volume pressions
V and viscosity q are calculated from the ex-
v = WlMl + X,M,)/p
(1)
7 = p(at - b / t )
(2)
where M 1 and M , are molecular weights of the components 1 and 2 and X, and X 2 are their mole fractions, respectively. t is the time of flow in seconds, a and b are the constants of the viscometer, and p is density.
0021-9568/89/1734-0005$01.50/0 0 1989 American Chemical Society
6 Journal of Chemical and Engineering Data, Vol. 34, No. 1, 1989
+
Table I. Experimental Values of Density, p, Viscosity, I), and Allied Parameters for the System N-Methylaniline 1,1,2,2-Tetrachloroethaneat 30 OC X15 p, gcm-s V , mL.mol-' V ,mL-mol-' II, c p AqE, CP d 6(AG*), cal-mol-' 1.5795 106.274 0.000 1.381 0.000 0.00 0.0000 0.00 +0.012 106.617 1.439 +0.021 0.1012 +0.20 +10.84 1.5168 106.951 +0.025 0.1991 +0.18 +17.70 1.4565 1.490 +0.036 +0.015 1.3941 107.276 1.541 +0.049 0.3016 +0.18 +23.07 -0,067 0.4007 +0.19 +27.46 1.3350 107.519 1.590 +0.061 -0,105 1.2753 107.807 1.633 +0.067 0.5004 +0.20 f29.09 -0.131 1.2154 0.6007 +0.17 +24.48 108.110 1.660 +0.057 -0.134 0.7017 +19.15 1.1552 108.437 1.686 +0.046 +0.16 1.0972 108.776 1.707 +0.031 -0.115 0.7992 +0.14 +13.06 -0.080 0.9013 +0.13 1.0367 109.145 1.730 +0.016 +6.65 0.o00 0.9782 109.548 1.751 0.00 0.000 0.00 1.0000
X1is mole fraction of N-methylaniline.
+
Tabte 11. Experimental Values of Density, p, Viscosity, I), and Allied Parameters for the System N-Methylaniline Dimethyl Sulfoxide at 30 "C X," p . pcm-s V , mL.mol-' VE, mL.mo1-l r ) , CP AnE, CP d 6(AG'). cal.mol-' 71.646 O.OO0 1.803 0.0000 1.0905 0.000 0.00 0.00 1.0734 1.844 0.1010 +0.28 +0.045 +0.047 +21.12 75.519 0.2001 1.0589 +0.24 +0.040 +0.069 79.270 1.861 +32.52 +0.028 +0.152 1.939 0.3007 1.0456 +0.39 +61.38 83.071 86.752 2.046 0.3986 1.0340 +0.58 -0.002 +0.264 +96.56 0.4987 1.0230 -0.023 +0.313 90.525 2.030 +111.14 +0.65 1.0131 -0.078 94.321 2.106 +116.40 0.6003 +0.72 +0.335 0.6987 1.0043 +0.87 -0.136 +0.354 97.992 2.120 +119.95 101.646 0.9950 -0,348 2.057 +99.39 0.8007 +0.97 +0.296 105.781 0.9015 0.9860 +0.96 -0.034 +0.155 1.911 +55.33 0.000 109.548 1.0000 0.9782 1.751 0.o00 0.00 0.00
Xl is mole fraction of N-methylaniline. Excess molar volume, VE, excess viscosity, AqE, and excess molar Gibbs free energy of activation of flow, 6(AG*), are calculated by using the expressions VE
=
v,,, - ( X 1 V l + X 2 V 2 )
0.00
(3)
-'d-
-0.10-
E
-
-
Subscripts 1 and 2 refer to components 1 and 2; R is the gas constant and T is the temperature in absolute degrees. Grunberg and Nissan's parameter, d ( 70), is calculated from the expression In qmlX= X, In o1
+ X , In q2 + X,X,d
E w >
-0.30-
(6)
Each set of results was fitted with Redlich-Kister equation ( 7 7 ) of the form AE = XlX2[ao
+ a , ( X , - X,) + a , ( X , - X,),]
where n is the number of measurements and p the number of coefficients. Results and Dlscusslon
The experimental values of density, p , viscosity, q, and allied parameters for the two systems are given in Tables I and 11. The coefficients a o, a and a of eq 7 along with the standard
,
- 040 00
(7)
where A E represents excess functions under consideration and ao,a,, and a , are the coemCmts of eq 7. The values of these coefficients for each function were determined by least-squares method for each set of liquid mixture. By substitution of these coefficients in eq 7,the calculated values of excess functions such as VE, AqE, and 6(AG*) were determined. The standard deviation (u)has been calculated from the equation
-0.20-
02 0 4 06 08 Mole fraction of N - methyl aniline
10
Figure 1. Excess molar volumes vs mole fraction of N-methylaniline for N-methylanllne 1,1,2,2-tetrachloroethane (0) and N-methylaniHne dimethyl sulfoxide (0)at 30 O C .
+
+
Table 111. Values of Coefficients of Eq 7 Determined by Least-Squares Method and Standard Deviation (a) funcsystem tion a. Ql Q2 U -0.3572 -0.6986 0.0424 0.017 N-methylaniline + V 0.2463 -0.0283 -0.0781 0.002 l,l,2,2-tetrachloro- AqE ethane 6(AG') 107.63 -26.01 -22.53 1.102 N-methylaniline + V -0.3179 -1.0565 0.0444 0.091 1.2440 0.9494 -0.2071 0.021 dimethyl sulfoxide AqE 6(AG') 439.33 288.12 -33.10 5.697
deviation (a) are given in Table 111. The experimental values of VE, AqE, and 6(AG *) are plotted against the mole fraction of N-methylaniline, and the curves so obtained are shown in Figures 1, 2, and 3, respectively.
Journal of Chemical and Engineering Data, Vol. 34,
No. 1, 1989 7
+
+
0.30-
5 - 0.20-
w
e
a
0.10-
0 00 00
I n case of the system N-methylaniline dimethyl sulfoxide (DMSO), both the liquids are polar. There is evidence for the self-association of DMSO (77). As is evident from the Figure 1, for the mixtures of N-methylaniline DMSO rich In DMSO, the excess molar volume VE shows positive deviation, suggesting weak interaction between the dissimilar molecules. The positive deviations in VE may be attributed to the dissociation of N-methylaniline molecules. As the concentration of N methylaniline increases in the mixture, the deviations in VE become increasingly negative with a well-marked minimum at X = 0.8 mole fraction of N-methylaniline demonstrating the complex formation. Dielectric and refractive index studies of benzene DMSO mixtures (78) have been discussed in terms of a-electron interaction. I n the case of N-methylaniline, owing to increased electron density on aromatic ring, there is a greater possibility of a-electron complex formation between N-methylaniline DMSO molecules. This contention is further supported by the positive values of AvE and 6(AG*) (Figures 2 and 3) and Nissank parameter, d (Table 11).
+
0.4 0.6 0.8 Mole fraction of N - methyl aniline
0.2
1.0
Figure 2. Excess vlscoslty vs mole fraction of N-methylaniline for N-methylaniline -t 1,1,2,2-tetrachloroethane (0)and N-methylaniline dimethyl sulfoxide (0)at 30 O C .
+
+
Glossary P
7 V
~(AG *) d U
R T M 0 0.0
density viscosity molar volume excess molar Gibbs free energy of activation of flow Grunberg and Nissan’s parameter standard deviation gas constant absolute temperature molecular weight
Subscripts 0.2 04 Mole fraction of N
0.8 methyl aniline
06
-
10
Figure 3. Excess molar W b s free energy of advation of Row vs mole fraction of N-methylanlline for N-methyianlline 4- l1l,2,2-tetrach1oroethane (0)and N-methylanillne -t dimethyl sulfoxide (0)at 30 ‘C.
The negative values of excess molar volume, VE, for the liquid systems are well explained by Prigogine (72)in terms of difference in size of the molecule or the dipole4ipole interaction between them leading to contraction in volume as compared to the ideal mixture. I n the N-methylaniline 1,1,2,2-tetrachloroethane system, at the lower fractions of N-methylaniline, the excess molar volume, VE, is found to be positive (Figure l), which may be attributed to the dissociation of N-methylaniline on addition of tetrachloroethane in excess. Above X = 0.2 mole fraction of N-methylaniline, the VE tends to become increasingly negative. This contraction in volume may be ascribed to the closer approach of the dissimilar molecules due to electrostatic interactions, and possibly a-electron donoracceptor complex formation occurs between the components of the mixture. Attempts ( 7, 5, 70, 73- 16)have been made to explain the behavior of liquid mixtures on the basis of sign and magnitude of excess viscosity AvE, excess molar Gibbs free energy of activation of flow 6(AG*), and Nissan’s parameter, d . The positive values of A$, 6(AG *), and d indicate strong specific interaction whereas their negative values show weaker interaction. For the system N-methylaniline lI1,2,2-tetrachloroethane, A$ and 6(AG *) are posltlve over the entire composition range, further supporting the complex formation between the components of the mixture.
+
+
exptl calcd
experimental calculated
Superscript E
excess function Registry No. DMSO, 67-68-5; N-methylaniline, 100-61-8; 1,1,2,2-
tetrachloroethane, 79-34-5.
Literature Clted (1) Fort, R. J.; Moore, W. R. Trans. Farachy SOC. 1988, 62, 11 12. (2) Kah, M.; Lobo, P. W.; Minano. A. S.; Solimo, H. Can. J . Chem. 1971, 49, 2605. (3) Solimo. H. 0.; Riggo, R.; Davaiio. F.; Katz, M. Can. J . Chem. 1973, 53, 1258. (4) Brown, I.; Smith, F. Aust. J . Chem. 1982, 15, 1. (5) Kumar, A.; Pitamber, N.; Prakash, S. Indian J . Pure Appl. Phys. 1984. 22.608. (6) Kumar,A:; Phkash, 0 . ;Prakash, S. J . Chem. Eng. Data 1881, 26, 64. (7) Prakash. 0.;Sinha, S. Acustica 1984, 54, 223. (8) Agnihotri, S. C.; Prakash, 0. ACOUS~. Left. 1965, 9 . 27. (9) Weissberger, A. Techniques of Or@nic Chemistry , 2nd ed.; Interscience: New York, 1955; Vol. V I I . (10) Grunberg. L.; Nissan, A. H. Nature (London) 1949, 164, 799. (11) Redlich, 0.;Kister, A. T. Ind. Eng. Chem. 1948, 40, 341. ; Holland. Am(12) Prigogine, I . The Molecular Theory of S o l ~ n s North sterdam, 1957. (13) Prakash, S.; Slvanarayana, K.; Prakash, 0. Can. J . Chem. 1860, 58, 942. (14) Ramamoorthy, K. Indian J . Pure Appl. Phys. 1973, 1 1 , 554. (15) Nigam, R. K.; Singh, P. P. Indlan J . Chem. 1971, 9 , 691. (16) Nigam, R. K.; Mahi, B. S. Indlan J . Chett?.1971, 9 , 1255. (17) Drinkard, W.; Kivelson, D. J . Phys. Chem. 1958. 62, 1494. (18) Lindberg, J. J.; Kenttama, J.; Nissema, A. Suom. Kemistil. 6 1861, 3 4 , 98, 156.
__
Received for review August 7, 1986. Revised November 24, 1987. Accepted July 12, 1988.
