J. Chem. Eng. Data 1987, 32, 409-412
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systems benzene (1)-ethyl acetate (2), benzene (1)-carbon tetrachloride (2), ethyl acetate (1)-carbon tetrachloride (2), and cyclohexane (1)-carbon tetrachloride (2), the density increment is negative over the entire range of composition of the mixture. However, for the systems benzene (1)-cyclohexane (2) and ethyl acetate (1)-cyclohexane (2), the density increment is positive; for the latter system it is largest of all. For mixtures exhibiting positive refractive index increments the density increment is negative (see, for instance, mixtures I and I1 given in Table I). A reverse situation exists in the case of ethyl acetate (1)-cyclohexane (2) wherein the density increment is positive but refractive index increment is negative. On the other hand, for a few mixtures (see, for instance, mixtures V and VI given in Table I) both the increments are negative: in one case (mixture 111) both the increments are positive. Thus, there appears to be no strict correlation between either the sign or magnitudes of these increments. From a general observation, it is apparent that if the first component of the mixture possesses higher values of either density or refractive index than the second component, then the increments are found to be positive. I f on the other hand, the first component has lower values than the second then negative values of the increments are prevalent.
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Flgure 4. Dependence of density increment on volume fraction of the first-named component in the mixture at 20 'C: (0)benzene (1)cyclohexane (2); (e)ethyl acetate (1)-cyclohexane (2); (A) benzene (lkcarbon tetrachloride (2); (A)ethyl acetate (Itcarbon tetrachloride (2); (0)benzene (1)-ethyl acetate (2); (0)cyclohexane (1)-carbon tetrachloride (2). of cyclohexane with benzene or ethyl acetate. Variation of refractive index for all the three wavelengths (589, 546, and 436 nm) as a function of 4 is shown in Figure 2. As expected, refractive index is higher for the mercury blue line (436 nm) than the mercury green line (546 nm). However, for sodium yellow line (589 nm) lower values of refractive indices than at either 546 or 436 nm are observed. For all the systems, the refractive index versus 4 curves are slightly deviated from a straight-line behavior. Dependence of refractive index increment on 4 is shown in Figure 3. Mixtures of benzene with ethyl acetate, carbon tetrachloride or cyclohexane exhibit positive values for the increment for all the wavelengths. However, mixtures of ethyl acetate with cyclohexane or carbon tetrachloride and cyclohexane (1)-carbon tetrachloride (2) exhibit negative refractive index increments. I n all the cases, the refractive index increments have shown increasing tendencies with a decrease in wavelength. The highest (and positive) values of refractive index increments are observed for the benzene (1)-ethyl acetate (2) system and the lowest (and negative) values are observed in the case of cyclohexane (1)-carbon tetrachloride (2) system. No strict linearity is observed for any of the systems as seen in Figure 3. Dependence of density increment on volume fraction of the first component of the mixture is shown in Figure 4. For the
Acknowledgment
I thank Professor Petr Munk of the University of Texas (Austin) for the experimental facilities, Professor P. E. Cassidy of Southwest Texas State University for the facilities provided during the preparation of this manuscript, and Mrs. Sue Hall for typing the manuscript. Registry No. Benzene, 71-43-2; cyclohexane, 110-82-7; ethyl acetate, 141-78-6; carbon tetrachloride, 56-23-5.
Llterature Cited (1) Aminabhavi, T. M.; Munk, P. Macromolecules 1979, 12, 607. (2) Aminabhavi, T. M.; Munk, P. Mecromolecules 1979, 12, 1186. (3) Chu, S. G.; Munk, P. Macromolecules 1978, 1 7 , 879. (4) Aminabhavi, T. M. J. Chem. Educ. 1983, 6 0 , 117. (5) Huglin, M. B., Ed. Light Scattering from Polymer Solutions; Academic: New York, 1972. (6) Letcher, T. M.; Bayles, J. W. J. Chem. Eng. Data 1971, 16, 266.
Received for review January 3, 1986. Revised manuscript received October IO, 1986. Accepted April 24, 1987.
Densities and Viscosities of Binary Liquid Mixtures at 45 O C Lata S. Manjeshwar and Tejraj M. Aminabhavl" Department of Chemistry, Karnatak University, Dharwad 580 003, India
Densities and viscoslties for 14 binary liquld mixtures comprlslng carbon tetrachloride, cyclohexane, methyl ethyl ketone, benzene, p -xylene, bromobenzene, dimethyl sulfoxide, dlmethylformamide, nltromethane, ethyl acetate, and methanol at 45 OC over the whole range of mlxture comDosltlons are Presented.
comprising carbon tetrachloride, cyclohexane, methyl ethyl ketone, dimethyl sulfoxide, dimethylformamide, nitromethane, benzene, bromobentene, ethyl acetate, p -xylene, and methanol. I n continuation of this research we now present additional data of densities and viscositites of 14 binary mixtures comprising the same solvents. The properties were studied over the entire range of composition of the mixture.
Introductlon
Experlmentai Section
I n our earlier studies ( 1-3)densities and viscosities have been measured at 25 and 35 OC for several binary mixtures
All chemicals used were of commercial products of the highest available purity (BDH). These were further purified by
0021-956818711732-0409$0 1.5010
0 1987 American Chemical Society
410
Journal of Chemical and Engineering Data, Vol. 32, No. 4, 1987
Table I. Data for Pure Comoonents at 25
O C
viscosity, CP
boiling point, "C solvent
found
lit.
ref
benzene carbon tetrachloride cyclohexane methyl ethyl ketone dimethyl sulfoxide ethyl acetate methanol nitromethane dimethylformamide bromobenzene p-xylene
80.00 76.2 80.10 79.00 190.00 77.10 64.20 100.20 152.80 155.90 137.50
80.10 76.75 80.74 79.6 189.85 17.26 65.15 100.80 153.00 156.05 138.00
8 8 8 I3 13 8 13 13 13 4
14
found 0.6010 0.8920 0.8830 0.4750 2.0240 0.4390 0.5900 0.6270 0.8050 1.0810 0.6150
density, g/cm3
lit. 0.5990 0.9020 0.8860 0.4800 2.0210 0.4240 0.5470 0.6200 0.8001 1.0400 0.6000
ref 8 8
found 0.8742 1.5787 0.7759 0.8008 1.0965 0.8948 0.7857 1.1255 0.9481 1.4982 0.8561
8
4 11
12 13 13 14 14 14
lit.
ref
0.8737 1.5840 0.7740 0.7997 1.0960 0.8945 0.7865 1.1313 0.9440 1.4980 0.8567
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