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Excess enthalpies at 298.15 K for binary mixtures of toluene + an n-alkane
M-999 J. Chem. Thermodynamics 1979,11,8254X28
Excess enthalpies at 298.15 K for binary mixtures of toluene + an n-alkane R. L. ARENOSA, M. DfAZ PERA
C. MENDIRmA,
G. TARDAJOS, and
Departamento de Quimica Fisica, Facultad de Quimicas, Universidad Complutense, Madrid-3, Spain (Received 4 December 1978) Molar excess enthalpies of the binary mixtures toluene + n-octane, + n-decane, $ ndodecane, + n-tetradecane, and + n-hexadecane have been measured at 298.15 K as a function of composition.
1. Introduction With this work we continue our systematic determination of excess thermodynamic properties HE, YE, GE, etc., for binary mixtures of an n-alkane + a fixed component. In this paper we report results obtained for the sequence consisting of toluene as the fixed component and an n-alkane with an even number of C-atoms from octane to n-hexadecane.
2. Experimental The calorimeter and the experimental technique used are described elsewhere,(l) and so are the source and purification procedures for the n-alkanes.(2*3) Toluene (Riedel, chromatography quality) was stripped of thiophene by sulphuric acid treatment, washed until neutral, and fractionally distilled at reflux ratio 50. The middle fractions were flushed over sodium wire. The density of the fraction used was p(298.15 K) = 0.86225 g cmm3 and its purity was checked by gas chromatography. This density is in good agreement with literature values.(4)
3. Results Table 1 lists the experimental results together with their deviations SHE with respect to values calculated from equations fitted to a polynomial of the type: HE/J mol- ’ = ~(1 -x)ZiA,(2x - l)i, (1) where x is the mole fraction of toluene. We t?nd that our HE values are consistent with those reported (5) for toluene + n-hexane. The coefficients Ai for each mixture 0021-9614/79/090825+04 %01.00/O
0 1979AcademicPressInc. (London)Ltd.
R. L. ARENOSA,
826
C. MENDUmA,
G. TARDAJOS,
AND M. DfAZ PERA
TABLE
1, M A?r excess enthalpies HE and values of SHE = {HYDE uation 1) - P(expt.)} at 298.15 K
x -I____
HE Jmol-l
SHE m
X
xC,Hs
0.1396
-0.0
0.2362 0.3143 0.3788 0.4342 0.4801 0.5195 0.5422 0.5554 0.5633
225 358 443 498 534 555 565 568 568 568
1.1 -0.5 -1.7 -1.8 -0.5 -0.0 0.4 0.8 0.4
0.1529 0.2668 0.3526 0.4158 0.4706 0.5160 0.5534 0.5546 0.5733 0.5866 0.5929
243 392 482 531 563 581 589 589 591 591 592
-0.4 1.1 1.5 -0.5 -1.2 -1.2 -1.2 -1.3 -0.7 -0.7 0.6
0.1767 0.2937 0.3812 0.4509 0.5054 0.5500 0.5879 0.6064 0.6214 0.6227 0.6399
279 429 519 576 608 623 629 630 628 628 624
-0.1 0.8 -1.1 -0.7 0.5 -0.5 0.0 1.2 0.8 1.0 0.6
0.1996 0.3299 0.4251 0.4952 0.5517 0.5821 0.5961 0.5990 0.6168 0.6328
321 497 597 650 678 686 688 689 689 689
0.1 -0.0 0.0 -0.3 -0.1 -0.6 -0.3 -0.2 -1.1 -0.3
0.5839 0.5858 0.6055 0.6106 0.6280 0.6332 0.6517 0.6527 0.6704 0.6783
-. HE J mol-l
___SHE J mol-l
x
--
HE
J mol-1
SHE J mol-”
__-
-I- (1 - x)CsHls 566 566 561 560 554 552 543 543 533 529
0.6 1.0 0.5 1.2 0.2 E 0:2 -0.1 0.7
-0.9
0.6876 0.7037 0.7065 0.7375 0.7719 0.8080 0.8482 0.8942 0.9438
521 509 508 480 443 395 333 251 144
-1.0 0.1 -0.2 -0.1 -0.9 -1.1 0.2 0.3
0.7133 0.7276 0.7336 0.7410 0.7638 0.7958 0.8300 0.8655 0.9066 0.9515
543 532 524 520 493 453 402 339 252 143
1.2 2.1 -0.5 2.4 -0.2 -0.4 -0.9 -1.0 -1.3 0.7
0.7422 0.7540 0.7660 0.7664 0.7962 0.8244 0.8545 0.8865 0.9224 0.9593
560 553 539 536 499 457 404 337 250 141
-2.5 2.1 1.7 -1.3 -0.8 -0.3 -0.0 -0.2 1.0 -0.3
0.7518 0.7627 0.7772 0.7803 0.7905 0.8107 0.8433 0.8794 0.9181 0.9600
625 617 600 592 584 548 489 408 301 165
-0.7 2.4 3.1 -1.4 4.2 -1.3 -1.6 -2.4 -3.4 1.6
XC& + (1 - xGJH,, 0.6123 0.6141 0.6334 0.6397 0.6558 0.6616 0.6804 0.6808 0.6981 0.7060
xC,Hs 0.6482 0.6578
590 588 584 582 576 574 564 564 554 547
1.0 --0.6 -0.0 -0.0 -0.0 0.5 z: 1:2 -0.2
+ (1 - x)GzHza 622 616 4::
0.6722 0.6773 0.6929 0.6982
613 607 602 595
-;;
0.7105 0.7193 0.7269 0.7412
590 580 577 565
-g
xGH~ 0.6359 0.6561 0.6624 0.6777 0.6883 0.7006 0.7099 0.7252 0.7293 0.7466
-I- (1 688 684 684 677 674 666 662 650 649 633
1:3 -2.4
0:7 1.4
x)CJIw, -0.9 -0.7 -y-i 0:6 -0.3 0.9 -0.0 2.1 1.6
HE FOR
TOLUENE TABLE
x
HE Jmol-iJmol-l
SHE
827
+ n-AL?SANES l-continued
HE i3HE Jmol-lJmol-l
x
x
~~ Jmol-lP
SHE
690 656 612 555 484 392 280 134
-0.5 0.0 0.0 -0.0 -0.4 -1.3 -0.3 0.4
XC&, + (1 - xYZJ-L~ 0.1552 0.2755 0.3689 0.4440 0.5017 OS.504 0.5925 0.6246 0.6279
293
-0.7 3.3 -0.1 -2.1 -2.7 -1.7 -0.9 -0.8 0.0
485 607 687 734 762 775 776 777
0.6415 0.6574 0.6588 0.6770 0.6850 0.6960 0.7159 0.7374
776 772 772 764 762 753 738 718
0.7610 0.7855 0.8116 0.8397 0.8691 0.9011 0.9346 0.9713
0.9 1.0 1.4 0.9 3.0 0.6 0.2 0.2
are given in table 2; the standard deviations @HE) are included. The experimental results are plotted on figure 1. The curves are drawn from equation (I), using the appropriate .coefficients from table 2.
0
0.2
0.4
0.6
0.8
1
xC7Hs
+ (1 -
X
FIGURE
0, Cm; q ,
1. Molar Cm; A,
excess G4;
enthalpies
0, Cm
HE(298.15
K)
for
x)n-CkHao+~.
A,
CS;
R. L. ARBNOSA,
828
TABLE
xC& xG& XC& xC& .+H,
-t + + -If
(1 (1 (1 (1 (1
-
x)CsH,, xKX%m xPX-Iz~ x)Cd-bo -4G&.x
C. MENDmA,
G. TARDAJOS,
AND M. DfAZ PERA
2. Coefficients of equation (1) and standard deviations cr(HE) -4
Al
AZ
A3
4
2245.31 2307.76 2421.91 2613.04 2942.15
486.88 737.22 957.86 1198.49 1390.32
-4.31 156.58 176.34 444.43 418.88
49.64 -24.07 -1.74 209.31 - 17.27
239.03 230.70
@HE) J mol-l 0.9 1.1 1.4 1.7 1.5
REFERENCES 1. 2. 3. 4.
Diaz Peiia, M.; Menduiiia, C. An. Quim. 1973,69,857. Diaz Peiia, M.; Menduiiia, C. J. Chem. Thermodynamics 1974,6,387. Diaz Pefia, M.; Menduiiia. C. J. Chem. Thermodynamics 1974,6,1097. Rossini, F. D. et al. Selected Values of Physical and l%ermadynamic Properties of Hydrocarbons and Related Compounds. API Research Project 44, 1954. 5. Paz Andrade, H. I.; Baluja, M. C.; Nuilez, L. An. Quim. 1970, 66, 949.
Excess enthalpies at 298.15 K for binary mixtures of toluene + an n-alkane R. L. ARENOSA, M. DfAZ PERA
C. MENDIRmA,
G. TARDAJOS, and
Departamento de Quimica Fisica, Facultad de Quimicas, Universidad Complutense, Madrid-3, Spain (Received 4 December 1978) Molar excess enthalpies of the binary mixtures toluene + n-octane, + n-decane, $ ndodecane, + n-tetradecane, and + n-hexadecane have been measured at 298.15 K as a function of composition.
1. Introduction With this work we continue our systematic determination of excess thermodynamic properties HE, YE, GE, etc., for binary mixtures of an n-alkane + a fixed component. In this paper we report results obtained for the sequence consisting of toluene as the fixed component and an n-alkane with an even number of C-atoms from octane to n-hexadecane.
2. Experimental The calorimeter and the experimental technique used are described elsewhere,(l) and so are the source and purification procedures for the n-alkanes.(2*3) Toluene (Riedel, chromatography quality) was stripped of thiophene by sulphuric acid treatment, washed until neutral, and fractionally distilled at reflux ratio 50. The middle fractions were flushed over sodium wire. The density of the fraction used was p(298.15 K) = 0.86225 g cmm3 and its purity was checked by gas chromatography. This density is in good agreement with literature values.(4)
3. Results Table 1 lists the experimental results together with their deviations SHE with respect to values calculated from equations fitted to a polynomial of the type: HE/J mol- ’ = ~(1 -x)ZiA,(2x - l)i, (1) where x is the mole fraction of toluene. We t?nd that our HE values are consistent with those reported (5) for toluene + n-hexane. The coefficients Ai for each mixture 0021-9614/79/090825+04 %01.00/O
0 1979AcademicPressInc. (London)Ltd.
R. L. ARENOSA,
826
C. MENDUmA,
G. TARDAJOS,
AND M. DfAZ PERA
TABLE
1, M A?r excess enthalpies HE and values of SHE = {HYDE uation 1) - P(expt.)} at 298.15 K
x -I____
HE Jmol-l
SHE m
X
xC,Hs
0.1396
-0.0
0.2362 0.3143 0.3788 0.4342 0.4801 0.5195 0.5422 0.5554 0.5633
225 358 443 498 534 555 565 568 568 568
1.1 -0.5 -1.7 -1.8 -0.5 -0.0 0.4 0.8 0.4
0.1529 0.2668 0.3526 0.4158 0.4706 0.5160 0.5534 0.5546 0.5733 0.5866 0.5929
243 392 482 531 563 581 589 589 591 591 592
-0.4 1.1 1.5 -0.5 -1.2 -1.2 -1.2 -1.3 -0.7 -0.7 0.6
0.1767 0.2937 0.3812 0.4509 0.5054 0.5500 0.5879 0.6064 0.6214 0.6227 0.6399
279 429 519 576 608 623 629 630 628 628 624
-0.1 0.8 -1.1 -0.7 0.5 -0.5 0.0 1.2 0.8 1.0 0.6
0.1996 0.3299 0.4251 0.4952 0.5517 0.5821 0.5961 0.5990 0.6168 0.6328
321 497 597 650 678 686 688 689 689 689
0.1 -0.0 0.0 -0.3 -0.1 -0.6 -0.3 -0.2 -1.1 -0.3
0.5839 0.5858 0.6055 0.6106 0.6280 0.6332 0.6517 0.6527 0.6704 0.6783
-. HE J mol-l
___SHE J mol-l
x
--
HE
J mol-1
SHE J mol-”
__-
-I- (1 - x)CsHls 566 566 561 560 554 552 543 543 533 529
0.6 1.0 0.5 1.2 0.2 E 0:2 -0.1 0.7
-0.9
0.6876 0.7037 0.7065 0.7375 0.7719 0.8080 0.8482 0.8942 0.9438
521 509 508 480 443 395 333 251 144
-1.0 0.1 -0.2 -0.1 -0.9 -1.1 0.2 0.3
0.7133 0.7276 0.7336 0.7410 0.7638 0.7958 0.8300 0.8655 0.9066 0.9515
543 532 524 520 493 453 402 339 252 143
1.2 2.1 -0.5 2.4 -0.2 -0.4 -0.9 -1.0 -1.3 0.7
0.7422 0.7540 0.7660 0.7664 0.7962 0.8244 0.8545 0.8865 0.9224 0.9593
560 553 539 536 499 457 404 337 250 141
-2.5 2.1 1.7 -1.3 -0.8 -0.3 -0.0 -0.2 1.0 -0.3
0.7518 0.7627 0.7772 0.7803 0.7905 0.8107 0.8433 0.8794 0.9181 0.9600
625 617 600 592 584 548 489 408 301 165
-0.7 2.4 3.1 -1.4 4.2 -1.3 -1.6 -2.4 -3.4 1.6
XC& + (1 - xGJH,, 0.6123 0.6141 0.6334 0.6397 0.6558 0.6616 0.6804 0.6808 0.6981 0.7060
xC,Hs 0.6482 0.6578
590 588 584 582 576 574 564 564 554 547
1.0 --0.6 -0.0 -0.0 -0.0 0.5 z: 1:2 -0.2
+ (1 - x)GzHza 622 616 4::
0.6722 0.6773 0.6929 0.6982
613 607 602 595
-;;
0.7105 0.7193 0.7269 0.7412
590 580 577 565
-g
xGH~ 0.6359 0.6561 0.6624 0.6777 0.6883 0.7006 0.7099 0.7252 0.7293 0.7466
-I- (1 688 684 684 677 674 666 662 650 649 633
1:3 -2.4
0:7 1.4
x)CJIw, -0.9 -0.7 -y-i 0:6 -0.3 0.9 -0.0 2.1 1.6
HE FOR
TOLUENE TABLE
x
HE Jmol-iJmol-l
SHE
827
+ n-AL?SANES l-continued
HE i3HE Jmol-lJmol-l
x
x
~~ Jmol-lP
SHE
690 656 612 555 484 392 280 134
-0.5 0.0 0.0 -0.0 -0.4 -1.3 -0.3 0.4
XC&, + (1 - xYZJ-L~ 0.1552 0.2755 0.3689 0.4440 0.5017 OS.504 0.5925 0.6246 0.6279
293
-0.7 3.3 -0.1 -2.1 -2.7 -1.7 -0.9 -0.8 0.0
485 607 687 734 762 775 776 777
0.6415 0.6574 0.6588 0.6770 0.6850 0.6960 0.7159 0.7374
776 772 772 764 762 753 738 718
0.7610 0.7855 0.8116 0.8397 0.8691 0.9011 0.9346 0.9713
0.9 1.0 1.4 0.9 3.0 0.6 0.2 0.2
are given in table 2; the standard deviations @HE) are included. The experimental results are plotted on figure 1. The curves are drawn from equation (I), using the appropriate .coefficients from table 2.
0
0.2
0.4
0.6
0.8
1
xC7Hs
+ (1 -
X
FIGURE
0, Cm; q ,
1. Molar Cm; A,
excess G4;
enthalpies
0, Cm
HE(298.15
K)
for
x)n-CkHao+~.
A,
CS;
R. L. ARBNOSA,
828
TABLE
xC& xG& XC& xC& .+H,
-t + + -If
(1 (1 (1 (1 (1
-
x)CsH,, xKX%m xPX-Iz~ x)Cd-bo -4G&.x
C. MENDmA,
G. TARDAJOS,
AND M. DfAZ PERA
2. Coefficients of equation (1) and standard deviations cr(HE) -4
Al
AZ
A3
4
2245.31 2307.76 2421.91 2613.04 2942.15
486.88 737.22 957.86 1198.49 1390.32
-4.31 156.58 176.34 444.43 418.88
49.64 -24.07 -1.74 209.31 - 17.27
239.03 230.70
@HE) J mol-l 0.9 1.1 1.4 1.7 1.5
REFERENCES 1. 2. 3. 4.
Diaz Peiia, M.; Menduiiia, C. An. Quim. 1973,69,857. Diaz Peiia, M.; Menduiiia, C. J. Chem. Thermodynamics 1974,6,387. Diaz Pefia, M.; Menduiiia. C. J. Chem. Thermodynamics 1974,6,1097. Rossini, F. D. et al. Selected Values of Physical and l%ermadynamic Properties of Hydrocarbons and Related Compounds. API Research Project 44, 1954. 5. Paz Andrade, H. I.; Baluja, M. C.; Nuilez, L. An. Quim. 1970, 66, 949.