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Excess volumes of n-hexane +n-heptane, +n-octane, +n-nonane, and +n-decane at 283.15, 298.15, and 313.15 K
M-1298 J. Chem. Thermodynamics 1981, 13,907-913
Excess volumes of n-hexane + n-heptane, + n-octane, + n-nonane, and + n-decane at 283.15, 298.15, and 313.15 K J. R. GOATES,
J. B. OTT,”
and R. B. GRIGG
Department of Chemistry, Brigham Young University, Provo, Utah 84602, U.S.A. (Received 5 February 1981) Excess volumes VE have been measured by the use of a vibrating-tube densimeter for nhexane + n-heptane, + n-octane, + n-nonane, + n-decane at 283.15,298.15, and 313.15 K. The VE’s are negative, and become systematically more negative as either the temperature or the size of the molecules increases. The VE(x) become less symmetrical about x = 0.5 as the size of the molecules increases.These results are in sharp contrast to the analogous results for (cyclohexane + n-alkane).
1. Introduction In an earlier paper,“) we reported the excess volumes of cyclohexane with the nalkanes from n-hexane to n-decane. These measurementswere made with a vibratingtube densimeter. In the present study we make similar measurements using the straight-chain hydrocarbon n-hexane instead of the cycloalkane as the common component.
2. Experimental MATERIALS
All the hydrocarbons except for the n-octane were Phillips Research-Grade chemicals and were used without further purification. Purity levels of 99.99, 99.98, 99.77, and 99.90 moles per cent were reported by the manufacturer for the C,H1,, C7H16, C9HZ0, and CloHz2, respectively. We verified these purities by g.c. analysis and from the change in melting temperature with fraction melted. Phillips “Pure Grade” n-octane (‘99 + per cent”) was further purified by shaking it with concentrated sulfuric acid, washing with water and dilute NaOH solutions, drying with CaCl,, and then distilling at a reflux ratio of approximately 50 in a 100 cm vacuum-jacketed distillation column packed with glass helices. The center third fraction of the distillation was retained for use. The purity, as determined from the change in melting temperature with fraction melted, was 99.83 moles per cent of C,H,,. a Author to whom correspondence should be addressed. 0021-9614/81/100907+07 SOl.OO/O
0 1981 Academic Press Inc. (London) Ltd.
J. R. GOATES. J. B. OTT, AND R. B. GRIGG
908
Tetrachloromethane, used to calibrate the densimeter, was purified by the fractional distillation of Matheson Coleman and Bell reagent-grade chemical in the same 100 cm vacuum-jacketed distillation column, again operated at a reflux ratio of approximately 50. The purity as determined from the change in melting temperature with fraction melted was better than 99.99 moles per cent of Ccl,. All mixtures were prepared in a special apparatus designed to reduce evaporation errors. This apparatus which is described in an earlier paper”’ is designed so that the amount and composition of the vapor above the solution is accurately known; and, hence, accurate calculations can be made of the change in composition of the liquid phase due to evaporation, We have shown that this change in composition can be an important source of error in the calculation of vE for a volatile mixture in a batchtype apparatus such as the vibrating-tube densimeter.
APPARATUS
The density measurements were made with a Sodev Model OlD Vibrating-Tube Densimeter designed by Picker, Tremblay, and Jolicoeur who have published a detailed description of the instrument. (‘) The period of vibration of the tube was measured with a Hewlett-Packard Model 5326-A Timer-Counter. The eight-digit readout of this instrument was fed into a Hewlett-Packard 9810A calculator, which is programmed to give a 30 s average period of vibration updated every 3 s. Temperature control to +0.0004 K was accomplished by enclosing the densimeter inside a Tronac Model CTB 1005 refrigerated constant-temperature bath controlled by a Tronac Model 1040 temperature controller. More detail of the experimental apparatus is given in earlier papers.(‘q3’
PROCEDURE
AND
EXPERIMENTAL
ACCURACY
The detailed procedure we followed to obtain the excessvolume 1/Eis given in an earlier paper.‘3’ In summary, we first calibrated the instrument with Ccl, and N, gas to obtain the constants a and b for the equation p = a+bz’,
(1)
which relates the period of vibration z of the vibrating tube to the density p of the solution flowing through the tube. We then used this calibration to obtain the densities of the pure components. To measure the densities of the mixtures, we alternately measured t for the mixtures and for the pure components so that the measurement for each mixture was bracketed by measurements on the pure substances.This procedure in effect recalibrates the instrument for each measurement and reduces the effect on the result of drifts in r. With an analysis similar to that in an earlier paper, we estimate that with the special sample-preparation techniques used, the uncertainty in VE is +0.0025 cm3 mol-’ at 298.15 K, and kO.004 cm3 mol -I at the other temperatures.
EXCESS VOLUMES
OF (xC~H,.,+(~-X)C~H~~+~}
FOR N = 7, 8, 9, AND
10
909
3. Results Excess volumes were obtained over the entire composition range for K. {xW-b, + (1 - xK4-b,+ 2)forN= 7,8,9,andlOat283.15,298.15,and313.15 The results are summarized in table 1. We fitted the results to the equation: VE/cm3 mol-’ = x(1 -x)
i A,(1 -2x)‘. j=O
(2)
Table 2 summarizes the coefficients in equation (2). Included in table 1 are the deviations 6VE of the individual points from equation (2), and the mean deviation (sVE) for each mixture. TABLE
1. Experimental
X
P g cm-’
densities p and excess volumes VE for {xC~H,~ + (1 -x)C,H,,+
YE WE ___.cm3 mol 1 cm3 mol - ’ xC,H,,
0 0.1145 0.2197 0.3067 0.4069 0.4948 0.5353
0.69204 0.68963 0.68735 0.68540 0.68313 0.68106 0.68010
-0.0101 -0.0164 -0.0156 - 0.0214 -0.0198 - 0.0204 xC,H,,
0 0.0866 0.2103 0.2858 0.3979 0.4877
0.67949 0.67761 0.67482 0.67311 0.67046 0.66830
-0.0094 - 0.0166 - 0.0234 - 0.0266 - 0.0291
0.66689 0.66471 0.66176 0.65996 0.65784 0.65501
-0.0102 - 0.0259 - 0.0357 - 0.0430 -0.0392 xC6H,,
0 0.0835 0.2385 0.3228 0.4289 0.5132
0.71064 0.70783 0.70235 0.69919 0.69502 0.69155
-0.0183 - 0.0397 -0.0509 - 0.0666 - 0.0700
P gcrn-j
+ (1 -x)C,H16
at T= 283.15 K
- 0.0006 -0.0012 0.0026 -0.0013 0.0008 o.oooo
0.5508 0.6025 0.6954 0.8099 0.9003 1
+ (1 --.x)C,H16
at T= 298.15 K
-0.0012 0.0014 - o.oooa 0.0004 - 0.0007
0.5984 0.6006 0.6967 0.7875 0.8941 1
.Y&,H,~ + (1 -x)C,H,, 0 0.0966 0.2243 0.3007 0.3885 0.5006
x
0.0026 0.0013 - 0.0020 -0.0043 0.0016
li WE
VE cm3 mol-’
0.67973 - 0.0204 0.67848 - 0.0199 0.67619 -0.0181 0.67329 -0.0133 0.67093 - 0.0067 0.66826 (WE)/cm’ mol-’
0.66554 - 0.0273 0.66547 - 0.0257 0.66303 - 0.0253 0.66064 -0.0185 0.65776 -0.0091 0.65482 (WE>/cm’ mol-’
cm3 mol
’
-0.0001 -0.0003 -0.0006 - 0.0003 0.0012 :
0.0012
0.0000 0.0015 -0.0016 - o.ooo1 o.ooto :
0.0012
at T = 313.15 K 0.5449 0.6076 0.7021 0.7960 0.8996 1
0.65386 - 0.0373 0.65224 - 0.0373 0.64973 - 0.0327 0.64718 - 0.0273 0.64425 -0.0116 0.64135 (6VE)/cm3 mol-’
+ (1 -.r)C,H,,
at T= 283.15 K
-0.0051 0.0018 0.0037 -0.0012 -0.0017
0.5595 0.6550 0.7505 0.8265 0.9162 1
0.68958 - 0.0684 0.68535 -0.0616 0.68090 - 0.0477 0.67720 - 0.0324 0.67268 - 0.0173 0.66825 (W)/cm’ mol-’
0.0030 0.0011 O.OCKM - 0.0030 0.0010 :
0.0026
-0.0008 -0.0007 0.0004 0.0021 - 0.ooo8 :
0.0026
910
1. R. GOATES,
x
P gcml3
VE
-
cm3 mol-’ x&H,, -0.0210 - 0.0505 - 0.0460 - 0.0687 -0.0818 - 0.0842
0 0.0615 0.1912 0.2296 0.3144 0.4287 0.5022
0.69866 0.69656 0.69188 0.69043 0.68716 0.68254 0.67942
i.0642 0.1805 0.2526 0.3177 0.4234 0.5143
0.68680 0.68456 0.68030 0.67753 0.67495 0.67060 0.66661
-0.0268 -0.0644 -0.0819 -0.0968 -0.1107 -0.1120
0 0.1049 0.2015 0.3196 0.3983 0.4421
0.72539 0.72107 0.71680 0.71124 0.70729 0.70499
-0.0423 -0.0671 -0.0984 -0.1114 -0.1158
J. B. OTT, TABLE
l-continued
WE __cm3 mol-’
x
+ (1 -x)C,H,, - 0.0030 -0.0011 0.0010 0.0018 o.OW3 0.0009
xCgH14 + (1 -x&H,,
xC,H,,
AND
R. B. GRIGG
P -3 8cm
0.5510 0.5667 0.6686 0.6835 0.8565 0.9287 1
- 0.0847 0.67729 0.0004 0.67661 - 0.0875 - 0.0027 0.67192 - 0.0770 0.0014 0.67123 - 0.0782 -0.0014 0.66264 - 0.0483 -0.0028 0.65877 - 0.0193 0.0057 0.65486 (FVE)/cm3 mole’ : O.ao26
at T = 313.15 K 0.5523 OS963 0.6577 0.7460 0.8185 0.9095 1
+ (1 -xQH,, -0.0019 0.0031 -0.0009 -0.0015 - 0.010
at r = 283.15 K
0.71380 0.71075 0.70710 0.70282 0.69920 0.69442 0.69193
x&H,, -0.0377 -0.0694 -0.1014 -0.1253 -0.1444 -0.1507
+ (1 -x)C9H,, -0.0033 o.oooo 0.0014 - o.Wo5 0.0006 0.0010
0 0.1491 0.2058 0.3254 0.3961 0.5175
0.70240 0.69579 0.69309 0.68707 0.68327 0.67633
xC6Hi4 + (1 -x)C,H,, - 0.0922 - 0.0024 -0.1160 0.0009 -0.1604 O.Wll - 0.1770 0.0028 - 0.1996 - 0.0036
WE ___cm3 mol-’
at T = 298.15 K
-0.cm3 00007 0.0013 -O.WlO -0.0021 O.WOl
0 0.0727 0.1549 0.2464 0.3203 0.4120 0.4577
VE cm3 mol-L
0.4923 0.5769 0.6899 0.7764 0.9252 1
0.66489 -0.1103 0.66260 -0.1104 0.65996 -0.1016 0.65561 -0.0851 0.65192 -0.0733 0.64701 -0.0395 0.64142 (hVE)/cm3 mold’:
0.70226 -0.1168 0.69747 -0.1197 0.69056 -0.1083 0.68490 -0.0947 0.67416 -0.0399 0.66826 (GVE)/cm3 mol-’
0.0012 -0.0012 0.0014 0.0029 -0.0034 O.WW 0.0018
0.0016 -0.Wo2 0.0018 -0.0016 o.Wo2 :
O&18
at 7 = 298.15 K 0.4956 0.68980 -0.1548 0.5776 0.68499 -0.1570 0.6492 0.68057 -0.1559 0.7078 0.67673 -0.1412 0.8089 0.66974 -0.1124 0.8942 0.66334 -0.0660 1 0.65482 (GVE)/cm3 mol-’
o.ooo7 O.OCO6 -0.oo4o o.OW5 -0.0016 0.0044 : 0.0023
at T = 313.15 K 0.5665 0.67333 - 0.1973 0.5946 0.67155 - 0.1974 0.6902 0.66526 -0.1744 0.7881 0.65838 -0.1516 0.8881 0.65070 -0.0917 1 0.64135 <@)/cm3 mol-’
-0.ooo8 - 0.0022 0.0063 -0.0036 O.Wll : 0.0033
EXCESS VOLUMES
OF {x&H,,
+(l-x)C,H,,+,}
TABLE
X
3
P
vE --_-.. cm3mol~’ x&H,,+
0 0.1099 0.2128 0.2871 0.3339 0.4410
0.73738 0.73233 0.72723 0.72325 0.72063 0.71423
0 0.0795 0.2027 0.2286 0.3337 0.4255 0.4786
0.72609 0.72239 0.71618 0.71481 0.70891 0.70328 0.69985
0 0.0793 0.1762 0.2336 0.3433 0.4309 0.4403
0.71503 0.71124 0.70624 0.70314 0.69675 0.69120 0.69058
- 0.0558 -0.1043 -0.1277 -0.1410 -0.1642
SV” --__... cm’mol
’
(1 -x)C,,H,, 0.0003 - 0.0033 o.Ow3 0.0015 0.0030
-0.0011 0.0010 - 0.0005 -0.0007 0.0013 - 0.0005
xC&H,~ + (1 -x)C,,H,,
TABLE
- 0.0697 -0.1338 -0.1794 - 0.2394 -0.2704 - 0.2744
-0.0035 0.0054 - 0.0020 -0.0021 -O.oool -0.0014
.Y
--- P gcn-’
VE -~--. Lm3 mol. ’
6V” --__ _ cm-\ mol. ’
at T = 283.15 K 0.5724 0.6668 0.7458 0.8373 0.9207 1
- 0.0007 0.70555 -0.1791 -0.0015 0.69909 -0.1722 - 0.0024 0.69234 -0.1548 -0.0006 0.68440 -0.1160 0.0057 0.67645 - 0.0592 0.66826 (hVE)/cm3 rnol~’ : 0.0028
at T = 298.15 K 0.5587 0.6537 0.7471 0.8354 0.9148 1
0.69432 - 0.2263 0.68725 - 0.2232 0.67961 -0.1975 0.67169 -0.1492 0.66393 - 0.0895 0.65482 (6VE)/cm3 mol-’
0.0016 -0.0018 -0.0016 0.0017 0.0006 :
0.0014
at T= 313.15 K 0.4810 0.5729 0.6465 0.7296 0.8345 0.9081 1
0.68782 - 0.2807 0.68122 -0.2862 0.67602 -0.2810 0.66858 -0.2531 0.65897 -0.1917 0.65145 -0.1069 0.64135 (WE)/cm3 mol-’
0.0017 0.0036 - 0.0005 -0.0013 -0.0068 0.0085 :
0.0043
2. Coefficients of equation (2) at 283.15, 298.15, and 313.15 K for W,H,, + (1 -?oGHm+~~
-0.0040 0.0013 - 0.0045
-0.0137 0.0136 0.0314
-0.2729 - 0.3403 - 0.4482
0.0249 0.0376 0.0238
0.1143 - 0.0070 -0.0178
-0.4751 -0.6233 -0.7795 - 0.7003 -0.8943 - 1.1420
0.0885 0.1432 0.1479 0.1917 0.2473 0.2882
-
7
283.15 298.15 313.15
-0.0821 -0.1137 -0.1633
8
283.15 298.15 313.15
9
283.15 298.15 313.15 283.15 298.15 313.15
10
911
10
I--continued
xC&H,~ + (1 -x)C,,H,, - 0.0556 -0.1245 -0.1388 -0.1833 - 0.2088 -0.2211
FOR N = 7, 8, 9, AND
0.0397 0.0124 0.0654 0.0379 0.0829 0.0089
912
J. R. GOATES, J. B. OTT, AND R. B. GRIGG
0.2
0.6
0.4
0.8
1
x FIGURE 1. Excess volumes VE at 298.15 K for (xC,H,, + (1 -.x)C~H~~+~~. 0, n-heptane; 0, noctane; 0, n-nonane; A. n-decane; +, Marsh, Ott, and Cost&n w for n-decane;n, Marsh, Ott, and Richards”’ for n-undecane; 0, Ott, Marsh, and Stokes’@for n-dodecane.
A comparison of VE at 298.15 K for the different alkane-containing mixtures is shown in figure 1. Included in the figure are results for n-hexane + n-decane, + nundecane, and + n-dodecane obtained by one of the investigators in another laboratoryC4-@using a dilatometric method. The agreement between the results at the two laboratories for (n-hexane + n-decane), the one mixture studied at both places, is very satisfying. Over most of the composition range, the agreement is better than 0.0020 cm3 mall’ and the maximum difference is 0.0032 cm3 mol-‘. We found no other data with which to compare any of the results. It is interesting to compare the results of this study with the results for (cyclohexane + an n-alkane) that we reported earlier.“’ In the cyclohexane containing mixtures, the VE curves become more positive and more symmetrical about x = 0.5 with increasing hydrocarbon size while in the n-hexane-containing mixtures the VE curves become more negative and less symmetrical about x = 0.5 as the size of the hydrocarbon increases. In all of the nhexane-containing mixtures, the temperature coefficient is negative, i.e. VE is larger (less negative) at the lower temperature. The authors gratefully acknowledge the support given this project by the Brigham Young University ResearchDivision and by the National ScienceFoundation under
EXCESS VOLUMES OF (xC,H14 + (1 --x)C~H~~+~} FOR N = 7, 8, 9, AND 10
913
grant ENG 76-15592. The assistance of Daniel L. Thomas, Tori Ann McFall, and Jeffrey G. Priest with some of the experimental measurements is also appreciated. REFERENCES 1. 2. 3. 4. 5. 6.
Goates, J. R.; Ott, J. B.; Grigg, R. B. /. Chem. Thermodynamics 1979, 11, 497. Picker. P.; Tremblay. E.; Jolicoeur. J. J. Solution Chem. 1974, 3, 377. Goates. J. R.; Ott, J. B.; Moellmer, J. F. J. Chem. Thermodynamics 1977, 9, 249. Marsh, K. N.; Ott, J. B.: Costigan, M. J. J. Chem. Thermodynamics 1980, 12, 343. Marsh. K. N.; Ott, J. B.: Richards, A. E. J. Chem. Thermodynamics 1980, 12, 897. Ott. J. B.; Marsh, K. N.; Stokes, R. H. J. Chem. Thermodynamics 1981, 13. 371.
Excess volumes of n-hexane + n-heptane, + n-octane, + n-nonane, and + n-decane at 283.15, 298.15, and 313.15 K J. R. GOATES,
J. B. OTT,”
and R. B. GRIGG
Department of Chemistry, Brigham Young University, Provo, Utah 84602, U.S.A. (Received 5 February 1981) Excess volumes VE have been measured by the use of a vibrating-tube densimeter for nhexane + n-heptane, + n-octane, + n-nonane, + n-decane at 283.15,298.15, and 313.15 K. The VE’s are negative, and become systematically more negative as either the temperature or the size of the molecules increases. The VE(x) become less symmetrical about x = 0.5 as the size of the molecules increases.These results are in sharp contrast to the analogous results for (cyclohexane + n-alkane).
1. Introduction In an earlier paper,“) we reported the excess volumes of cyclohexane with the nalkanes from n-hexane to n-decane. These measurementswere made with a vibratingtube densimeter. In the present study we make similar measurements using the straight-chain hydrocarbon n-hexane instead of the cycloalkane as the common component.
2. Experimental MATERIALS
All the hydrocarbons except for the n-octane were Phillips Research-Grade chemicals and were used without further purification. Purity levels of 99.99, 99.98, 99.77, and 99.90 moles per cent were reported by the manufacturer for the C,H1,, C7H16, C9HZ0, and CloHz2, respectively. We verified these purities by g.c. analysis and from the change in melting temperature with fraction melted. Phillips “Pure Grade” n-octane (‘99 + per cent”) was further purified by shaking it with concentrated sulfuric acid, washing with water and dilute NaOH solutions, drying with CaCl,, and then distilling at a reflux ratio of approximately 50 in a 100 cm vacuum-jacketed distillation column packed with glass helices. The center third fraction of the distillation was retained for use. The purity, as determined from the change in melting temperature with fraction melted, was 99.83 moles per cent of C,H,,. a Author to whom correspondence should be addressed. 0021-9614/81/100907+07 SOl.OO/O
0 1981 Academic Press Inc. (London) Ltd.
J. R. GOATES. J. B. OTT, AND R. B. GRIGG
908
Tetrachloromethane, used to calibrate the densimeter, was purified by the fractional distillation of Matheson Coleman and Bell reagent-grade chemical in the same 100 cm vacuum-jacketed distillation column, again operated at a reflux ratio of approximately 50. The purity as determined from the change in melting temperature with fraction melted was better than 99.99 moles per cent of Ccl,. All mixtures were prepared in a special apparatus designed to reduce evaporation errors. This apparatus which is described in an earlier paper”’ is designed so that the amount and composition of the vapor above the solution is accurately known; and, hence, accurate calculations can be made of the change in composition of the liquid phase due to evaporation, We have shown that this change in composition can be an important source of error in the calculation of vE for a volatile mixture in a batchtype apparatus such as the vibrating-tube densimeter.
APPARATUS
The density measurements were made with a Sodev Model OlD Vibrating-Tube Densimeter designed by Picker, Tremblay, and Jolicoeur who have published a detailed description of the instrument. (‘) The period of vibration of the tube was measured with a Hewlett-Packard Model 5326-A Timer-Counter. The eight-digit readout of this instrument was fed into a Hewlett-Packard 9810A calculator, which is programmed to give a 30 s average period of vibration updated every 3 s. Temperature control to +0.0004 K was accomplished by enclosing the densimeter inside a Tronac Model CTB 1005 refrigerated constant-temperature bath controlled by a Tronac Model 1040 temperature controller. More detail of the experimental apparatus is given in earlier papers.(‘q3’
PROCEDURE
AND
EXPERIMENTAL
ACCURACY
The detailed procedure we followed to obtain the excessvolume 1/Eis given in an earlier paper.‘3’ In summary, we first calibrated the instrument with Ccl, and N, gas to obtain the constants a and b for the equation p = a+bz’,
(1)
which relates the period of vibration z of the vibrating tube to the density p of the solution flowing through the tube. We then used this calibration to obtain the densities of the pure components. To measure the densities of the mixtures, we alternately measured t for the mixtures and for the pure components so that the measurement for each mixture was bracketed by measurements on the pure substances.This procedure in effect recalibrates the instrument for each measurement and reduces the effect on the result of drifts in r. With an analysis similar to that in an earlier paper, we estimate that with the special sample-preparation techniques used, the uncertainty in VE is +0.0025 cm3 mol-’ at 298.15 K, and kO.004 cm3 mol -I at the other temperatures.
EXCESS VOLUMES
OF (xC~H,.,+(~-X)C~H~~+~}
FOR N = 7, 8, 9, AND
10
909
3. Results Excess volumes were obtained over the entire composition range for K. {xW-b, + (1 - xK4-b,+ 2)forN= 7,8,9,andlOat283.15,298.15,and313.15 The results are summarized in table 1. We fitted the results to the equation: VE/cm3 mol-’ = x(1 -x)
i A,(1 -2x)‘. j=O
(2)
Table 2 summarizes the coefficients in equation (2). Included in table 1 are the deviations 6VE of the individual points from equation (2), and the mean deviation (sVE) for each mixture. TABLE
1. Experimental
X
P g cm-’
densities p and excess volumes VE for {xC~H,~ + (1 -x)C,H,,+
YE WE ___.cm3 mol 1 cm3 mol - ’ xC,H,,
0 0.1145 0.2197 0.3067 0.4069 0.4948 0.5353
0.69204 0.68963 0.68735 0.68540 0.68313 0.68106 0.68010
-0.0101 -0.0164 -0.0156 - 0.0214 -0.0198 - 0.0204 xC,H,,
0 0.0866 0.2103 0.2858 0.3979 0.4877
0.67949 0.67761 0.67482 0.67311 0.67046 0.66830
-0.0094 - 0.0166 - 0.0234 - 0.0266 - 0.0291
0.66689 0.66471 0.66176 0.65996 0.65784 0.65501
-0.0102 - 0.0259 - 0.0357 - 0.0430 -0.0392 xC6H,,
0 0.0835 0.2385 0.3228 0.4289 0.5132
0.71064 0.70783 0.70235 0.69919 0.69502 0.69155
-0.0183 - 0.0397 -0.0509 - 0.0666 - 0.0700
P gcrn-j
+ (1 -x)C,H16
at T= 283.15 K
- 0.0006 -0.0012 0.0026 -0.0013 0.0008 o.oooo
0.5508 0.6025 0.6954 0.8099 0.9003 1
+ (1 --.x)C,H16
at T= 298.15 K
-0.0012 0.0014 - o.oooa 0.0004 - 0.0007
0.5984 0.6006 0.6967 0.7875 0.8941 1
.Y&,H,~ + (1 -x)C,H,, 0 0.0966 0.2243 0.3007 0.3885 0.5006
x
0.0026 0.0013 - 0.0020 -0.0043 0.0016
li WE
VE cm3 mol-’
0.67973 - 0.0204 0.67848 - 0.0199 0.67619 -0.0181 0.67329 -0.0133 0.67093 - 0.0067 0.66826 (WE)/cm’ mol-’
0.66554 - 0.0273 0.66547 - 0.0257 0.66303 - 0.0253 0.66064 -0.0185 0.65776 -0.0091 0.65482 (WE>/cm’ mol-’
cm3 mol
’
-0.0001 -0.0003 -0.0006 - 0.0003 0.0012 :
0.0012
0.0000 0.0015 -0.0016 - o.ooo1 o.ooto :
0.0012
at T = 313.15 K 0.5449 0.6076 0.7021 0.7960 0.8996 1
0.65386 - 0.0373 0.65224 - 0.0373 0.64973 - 0.0327 0.64718 - 0.0273 0.64425 -0.0116 0.64135 (6VE)/cm3 mol-’
+ (1 -.r)C,H,,
at T= 283.15 K
-0.0051 0.0018 0.0037 -0.0012 -0.0017
0.5595 0.6550 0.7505 0.8265 0.9162 1
0.68958 - 0.0684 0.68535 -0.0616 0.68090 - 0.0477 0.67720 - 0.0324 0.67268 - 0.0173 0.66825 (W)/cm’ mol-’
0.0030 0.0011 O.OCKM - 0.0030 0.0010 :
0.0026
-0.0008 -0.0007 0.0004 0.0021 - 0.ooo8 :
0.0026
910
1. R. GOATES,
x
P gcml3
VE
-
cm3 mol-’ x&H,, -0.0210 - 0.0505 - 0.0460 - 0.0687 -0.0818 - 0.0842
0 0.0615 0.1912 0.2296 0.3144 0.4287 0.5022
0.69866 0.69656 0.69188 0.69043 0.68716 0.68254 0.67942
i.0642 0.1805 0.2526 0.3177 0.4234 0.5143
0.68680 0.68456 0.68030 0.67753 0.67495 0.67060 0.66661
-0.0268 -0.0644 -0.0819 -0.0968 -0.1107 -0.1120
0 0.1049 0.2015 0.3196 0.3983 0.4421
0.72539 0.72107 0.71680 0.71124 0.70729 0.70499
-0.0423 -0.0671 -0.0984 -0.1114 -0.1158
J. B. OTT, TABLE
l-continued
WE __cm3 mol-’
x
+ (1 -x)C,H,, - 0.0030 -0.0011 0.0010 0.0018 o.OW3 0.0009
xCgH14 + (1 -x&H,,
xC,H,,
AND
R. B. GRIGG
P -3 8cm
0.5510 0.5667 0.6686 0.6835 0.8565 0.9287 1
- 0.0847 0.67729 0.0004 0.67661 - 0.0875 - 0.0027 0.67192 - 0.0770 0.0014 0.67123 - 0.0782 -0.0014 0.66264 - 0.0483 -0.0028 0.65877 - 0.0193 0.0057 0.65486 (FVE)/cm3 mole’ : O.ao26
at T = 313.15 K 0.5523 OS963 0.6577 0.7460 0.8185 0.9095 1
+ (1 -xQH,, -0.0019 0.0031 -0.0009 -0.0015 - 0.010
at r = 283.15 K
0.71380 0.71075 0.70710 0.70282 0.69920 0.69442 0.69193
x&H,, -0.0377 -0.0694 -0.1014 -0.1253 -0.1444 -0.1507
+ (1 -x)C9H,, -0.0033 o.oooo 0.0014 - o.Wo5 0.0006 0.0010
0 0.1491 0.2058 0.3254 0.3961 0.5175
0.70240 0.69579 0.69309 0.68707 0.68327 0.67633
xC6Hi4 + (1 -x)C,H,, - 0.0922 - 0.0024 -0.1160 0.0009 -0.1604 O.Wll - 0.1770 0.0028 - 0.1996 - 0.0036
WE ___cm3 mol-’
at T = 298.15 K
-0.cm3 00007 0.0013 -O.WlO -0.0021 O.WOl
0 0.0727 0.1549 0.2464 0.3203 0.4120 0.4577
VE cm3 mol-L
0.4923 0.5769 0.6899 0.7764 0.9252 1
0.66489 -0.1103 0.66260 -0.1104 0.65996 -0.1016 0.65561 -0.0851 0.65192 -0.0733 0.64701 -0.0395 0.64142 (hVE)/cm3 mold’:
0.70226 -0.1168 0.69747 -0.1197 0.69056 -0.1083 0.68490 -0.0947 0.67416 -0.0399 0.66826 (GVE)/cm3 mol-’
0.0012 -0.0012 0.0014 0.0029 -0.0034 O.WW 0.0018
0.0016 -0.Wo2 0.0018 -0.0016 o.Wo2 :
O&18
at 7 = 298.15 K 0.4956 0.68980 -0.1548 0.5776 0.68499 -0.1570 0.6492 0.68057 -0.1559 0.7078 0.67673 -0.1412 0.8089 0.66974 -0.1124 0.8942 0.66334 -0.0660 1 0.65482 (GVE)/cm3 mol-’
o.ooo7 O.OCO6 -0.oo4o o.OW5 -0.0016 0.0044 : 0.0023
at T = 313.15 K 0.5665 0.67333 - 0.1973 0.5946 0.67155 - 0.1974 0.6902 0.66526 -0.1744 0.7881 0.65838 -0.1516 0.8881 0.65070 -0.0917 1 0.64135 <@)/cm3 mol-’
-0.ooo8 - 0.0022 0.0063 -0.0036 O.Wll : 0.0033
EXCESS VOLUMES
OF {x&H,,
+(l-x)C,H,,+,}
TABLE
X
3
P
vE --_-.. cm3mol~’ x&H,,+
0 0.1099 0.2128 0.2871 0.3339 0.4410
0.73738 0.73233 0.72723 0.72325 0.72063 0.71423
0 0.0795 0.2027 0.2286 0.3337 0.4255 0.4786
0.72609 0.72239 0.71618 0.71481 0.70891 0.70328 0.69985
0 0.0793 0.1762 0.2336 0.3433 0.4309 0.4403
0.71503 0.71124 0.70624 0.70314 0.69675 0.69120 0.69058
- 0.0558 -0.1043 -0.1277 -0.1410 -0.1642
SV” --__... cm’mol
’
(1 -x)C,,H,, 0.0003 - 0.0033 o.Ow3 0.0015 0.0030
-0.0011 0.0010 - 0.0005 -0.0007 0.0013 - 0.0005
xC&H,~ + (1 -x)C,,H,,
TABLE
- 0.0697 -0.1338 -0.1794 - 0.2394 -0.2704 - 0.2744
-0.0035 0.0054 - 0.0020 -0.0021 -O.oool -0.0014
.Y
--- P gcn-’
VE -~--. Lm3 mol. ’
6V” --__ _ cm-\ mol. ’
at T = 283.15 K 0.5724 0.6668 0.7458 0.8373 0.9207 1
- 0.0007 0.70555 -0.1791 -0.0015 0.69909 -0.1722 - 0.0024 0.69234 -0.1548 -0.0006 0.68440 -0.1160 0.0057 0.67645 - 0.0592 0.66826 (hVE)/cm3 rnol~’ : 0.0028
at T = 298.15 K 0.5587 0.6537 0.7471 0.8354 0.9148 1
0.69432 - 0.2263 0.68725 - 0.2232 0.67961 -0.1975 0.67169 -0.1492 0.66393 - 0.0895 0.65482 (6VE)/cm3 mol-’
0.0016 -0.0018 -0.0016 0.0017 0.0006 :
0.0014
at T= 313.15 K 0.4810 0.5729 0.6465 0.7296 0.8345 0.9081 1
0.68782 - 0.2807 0.68122 -0.2862 0.67602 -0.2810 0.66858 -0.2531 0.65897 -0.1917 0.65145 -0.1069 0.64135 (WE)/cm3 mol-’
0.0017 0.0036 - 0.0005 -0.0013 -0.0068 0.0085 :
0.0043
2. Coefficients of equation (2) at 283.15, 298.15, and 313.15 K for W,H,, + (1 -?oGHm+~~
-0.0040 0.0013 - 0.0045
-0.0137 0.0136 0.0314
-0.2729 - 0.3403 - 0.4482
0.0249 0.0376 0.0238
0.1143 - 0.0070 -0.0178
-0.4751 -0.6233 -0.7795 - 0.7003 -0.8943 - 1.1420
0.0885 0.1432 0.1479 0.1917 0.2473 0.2882
-
7
283.15 298.15 313.15
-0.0821 -0.1137 -0.1633
8
283.15 298.15 313.15
9
283.15 298.15 313.15 283.15 298.15 313.15
10
911
10
I--continued
xC&H,~ + (1 -x)C,,H,, - 0.0556 -0.1245 -0.1388 -0.1833 - 0.2088 -0.2211
FOR N = 7, 8, 9, AND
0.0397 0.0124 0.0654 0.0379 0.0829 0.0089
912
J. R. GOATES, J. B. OTT, AND R. B. GRIGG
0.2
0.6
0.4
0.8
1
x FIGURE 1. Excess volumes VE at 298.15 K for (xC,H,, + (1 -.x)C~H~~+~~. 0, n-heptane; 0, noctane; 0, n-nonane; A. n-decane; +, Marsh, Ott, and Cost&n w for n-decane;n, Marsh, Ott, and Richards”’ for n-undecane; 0, Ott, Marsh, and Stokes’@for n-dodecane.
A comparison of VE at 298.15 K for the different alkane-containing mixtures is shown in figure 1. Included in the figure are results for n-hexane + n-decane, + nundecane, and + n-dodecane obtained by one of the investigators in another laboratoryC4-@using a dilatometric method. The agreement between the results at the two laboratories for (n-hexane + n-decane), the one mixture studied at both places, is very satisfying. Over most of the composition range, the agreement is better than 0.0020 cm3 mall’ and the maximum difference is 0.0032 cm3 mol-‘. We found no other data with which to compare any of the results. It is interesting to compare the results of this study with the results for (cyclohexane + an n-alkane) that we reported earlier.“’ In the cyclohexane containing mixtures, the VE curves become more positive and more symmetrical about x = 0.5 with increasing hydrocarbon size while in the n-hexane-containing mixtures the VE curves become more negative and less symmetrical about x = 0.5 as the size of the hydrocarbon increases. In all of the nhexane-containing mixtures, the temperature coefficient is negative, i.e. VE is larger (less negative) at the lower temperature. The authors gratefully acknowledge the support given this project by the Brigham Young University ResearchDivision and by the National ScienceFoundation under
EXCESS VOLUMES OF (xC,H14 + (1 --x)C~H~~+~} FOR N = 7, 8, 9, AND 10
913
grant ENG 76-15592. The assistance of Daniel L. Thomas, Tori Ann McFall, and Jeffrey G. Priest with some of the experimental measurements is also appreciated. REFERENCES 1. 2. 3. 4. 5. 6.
Goates, J. R.; Ott, J. B.; Grigg, R. B. /. Chem. Thermodynamics 1979, 11, 497. Picker. P.; Tremblay. E.; Jolicoeur. J. J. Solution Chem. 1974, 3, 377. Goates. J. R.; Ott, J. B.; Moellmer, J. F. J. Chem. Thermodynamics 1977, 9, 249. Marsh, K. N.; Ott, J. B.: Costigan, M. J. J. Chem. Thermodynamics 1980, 12, 343. Marsh. K. N.; Ott, J. B.: Richards, A. E. J. Chem. Thermodynamics 1980, 12, 897. Ott. J. B.; Marsh, K. N.; Stokes, R. H. J. Chem. Thermodynamics 1981, 13. 371.