# Excess Transport Properties of Binary Mixtures of Quinoline with Xylenes at Different Temperatures

Authors: Sk. Fakruddin; Ch. Srinivasu; B. R. Venkateswara Rao; K. Narendra
Journal: Advances in Physical Chemistry
 (2012)

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## Abstract

The ultrasonic velocity and density of binary liquid mixtures of quinoline with o-xylene, m-xylene, and p-xylene have been measured over the entire range of composition atT = 303.15, 308.15, 313.15, and 318.15 K. Using these data, various parameters like adiabatic compressibility (β), intermolecular free length (Lf), and acoustic impedance (Z) and some excess parameters like excess adiabatic compressibility (βE), excess intermolecular free length (LfE), excess acoustic impedance (ZE), and excess ultrasonic velocity (uE) have been calculated for all the three mixtures. The calculated deviations and excess functions have been fitted to Redlich-Kister polynomial equation. The observed deviations have been explained on the basis of the intermolecular interactions present in these mixtures.


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## Body

## 1. Introduction

In studying the molecular interactions and physicochemical behaviour of binary liquid mixtures [1, 2], the knowledge of thermodynamic and acoustical properties is of great importance. The results are frequently used in process design in many chemical and industrial processes. The studies of binary mixtures containing aromatic hydrocarbons are interesting because they find applications in preferential interactions of polymers in mixed solvents and the studies of polymer phase diagrams. Quinoline is widely used in the manufacturing of dyes, pesticides, and solvent for resins and terpenes. Xylenes are used in printing, rubber, and leather industries. Basically, a binary liquid mixture is formed by the replacement of like contacts in pure liquids by unlike contacts in the mixture. The quantitative and qualitative analyses of excess functions provide information about the nature of molecular interactions in the binary mixtures [3–5]. The literature survey reveals that there has been practically no study of the binary mixtures of these systems from the point of view of their ultrasonic behaviour.In an attempt to explain the nature of interactions occurring between quinoline and xylenes, ultrasonic velocity and density of binary liquid mixtures of quinoline + o-xylene/m-xylene/p-xylene have been determined over the entire range of composition atT = 303.15, 308.15, 313.15, and 318.15 K. Using the experimental values of u and ρ, adiabatic compressibility (β), intermolecular free length (Lf), and acoustic impedance (Z) and some excess parameters like excess adiabatic compressibility (βE), excess intermolecular free length (LfE), excess acoustic impedance (ZE), and excess ultrasonic velocity (uE) have been calculated. The results were fitted to the Redlich-Kister polynomial equation. In the light of excess parameters, the intermolecular interactions have been estimated [8].


## 2. Experimental

### 2.1. Materials

The mass fraction of the liquids (obtained from Merck) is as follows: o-xylene (0.980), m-xylene (0.980), p-xylene (0.990), and quinoline (0.987). All the liquids used were further purified by standard procedure [9]. The purity of the samples was checked by comparing the experimental values of ultrasonic velocity and density with those available in the literature [6, 7] and these values are compiled in Table 1.Table 1
Comparison of experimental values of ultrasonic velocities (u) and densities (ρ) of pure liquids with the values reported in the literature.
Liquid
T/K
u/(m·s−1)
ρ/(Kg·m−3)
Experimental
Literature
Experimental
Literature
Quinoline
303.15
1553.68
1547a
1085.45
1085.79a
o-xylene
308.15
1338.75
1328.30b
870.70
870.73b
m-xylene
313.15
1304.21
1300.34b
855.70
855.47b
p-xylene
318.15
1288.43
1289.68b
852.80
852.26b
aNath [6].
bAl-Kandary et al. [7].


### 2.2. Procedure

Job’s method of continuous variation was used to prepare the mixtures of required proportions. The prepared mixtures were preserved in well-stoppard conical flasks. After mixing the liquids thoroughly, the flasks were left undisturbed to allow them to attain thermal equilibrium.The ultrasonic velocities were measured by using single crystal ultrasonic pulse echo interferometer (Mittal enterprises, India; Model: F-80X). It consists of a high-frequency generator and a measuring cell. The measurements of ultrasonic velocities were made at a fixed frequency of 3 MHz. The capacity of the measuring cell is 12 mL. The calibration of the equipment was done by measuring the velocity in carbon tetrachloride and benzene. The results are in good agreement with those reported in the literature [10]. The ultrasonic velocity has an accuracy of ±0.5 ms−1. The temperature was controlled by circulating water around the liquid cell from thermostatically controlled constant temperature water bath (accuracy ±0.01 K).The densities of pure liquids and liquid mixtures were measured by using a specific gravity bottle with an accuracy of ±0.5%. An electronic balance (Shimadzu AUY220, Japan), with a precision of ±0.1 mg, was used for the mass measurements. Averages of 4-5 measurements were taken for each sample.


## 2.1. Materials

The mass fraction of the liquids (obtained from Merck) is as follows: o-xylene (0.980), m-xylene (0.980), p-xylene (0.990), and quinoline (0.987). All the liquids used were further purified by standard procedure [9]. The purity of the samples was checked by comparing the experimental values of ultrasonic velocity and density with those available in the literature [6, 7] and these values are compiled in Table 1.Table 1
Comparison of experimental values of ultrasonic velocities (u) and densities (ρ) of pure liquids with the values reported in the literature.
Liquid
T/K
u/(m·s−1)
ρ/(Kg·m−3)
Experimental
Literature
Experimental
Literature
Quinoline
303.15
1553.68
1547a
1085.45
1085.79a
o-xylene
308.15
1338.75
1328.30b
870.70
870.73b
m-xylene
313.15
1304.21
1300.34b
855.70
855.47b
p-xylene
318.15
1288.43
1289.68b
852.80
852.26b
aNath [6].
bAl-Kandary et al. [7].


## 2.2. Procedure

Job’s method of continuous variation was used to prepare the mixtures of required proportions. The prepared mixtures were preserved in well-stoppard conical flasks. After mixing the liquids thoroughly, the flasks were left undisturbed to allow them to attain thermal equilibrium.The ultrasonic velocities were measured by using single crystal ultrasonic pulse echo interferometer (Mittal enterprises, India; Model: F-80X). It consists of a high-frequency generator and a measuring cell. The measurements of ultrasonic velocities were made at a fixed frequency of 3 MHz. The capacity of the measuring cell is 12 mL. The calibration of the equipment was done by measuring the velocity in carbon tetrachloride and benzene. The results are in good agreement with those reported in the literature [10]. The ultrasonic velocity has an accuracy of ±0.5 ms−1. The temperature was controlled by circulating water around the liquid cell from thermostatically controlled constant temperature water bath (accuracy ±0.01 K).The densities of pure liquids and liquid mixtures were measured by using a specific gravity bottle with an accuracy of ±0.5%. An electronic balance (Shimadzu AUY220, Japan), with a precision of ±0.1 mg, was used for the mass measurements. Averages of 4-5 measurements were taken for each sample.


## 3. Theory

From the experimental data of ultrasonic velocity and density various thermodynamic parameters are evaluated using standard equations.Adiabatic compressibility:(1)β=1ρu2,
where ρ and u are density and ultrasonic velocity, respectively.Inter molecular free length:(2)Lf=KT·β1/2,
where KT is the temperature dependent constant [11].Acoustic impedance:(3)Z=ρu.
The strength of interaction between the component molecules of binary mixtures is well reflected in the deviation of the excess functions from ideality [12]. The excess properties such as βE, LfE, ZE, and uE have been calculated using
(4)YE=Ymix-[x1Y1+x2Y2],
where YE is βE, LfE,  ZE, or uE and x represents mole fraction of the component and subscript 1 and 2 for the components 1 and 2, respectively.The excess values of above parameters for each mixture have been fitted to Redlich-Kister polynomial equation [13]:
(5)YE=X1·X2∑i=0nAi(X1-X2)i.
The values of the coefficients Ai were calculated by a method of least squares along with the standard deviation σ(YE). The coefficient is adjustable to the parameters for a better fit of the excess functions. The standard deviation values were obtained from
(6)σ(YE)=[∑i=1n(YexptE-YcalE)2m-n]1/2,
where m is the number of experimental points, n is the number of parameters, and Yexpt and Ycal are the experimental and calculated parameters, respectively.


## 4. Results and Discussion

The structures of the components taken up for study are given in Scheme1.Scheme 1The experimental values of ultrasonic velocity (u) and density (ρ) for the three binary mixtures over the entire composition range and at temperatures T = 303.15, 308.15, 313.15, and 318.15 K are given in Table 2. The values of the Redlich-Kister polynomial coefficients Ai evaluated by the method of least squares along with standard deviation are given in Table 3. Plots of βE, LfE, ZE, and uE against mole fraction of quinoline for all the three mixtures are given in Figures 1–4.Table 2
Ultrasonic velocities (u) and densities (ρ) for binary mixtures at T = 303.15, 308.15, 313.15, and 318.15 K.
x
1
T = 303.15 K
T = 308.15 K
T = 313.15 K
T = 318.15 K
u /(m·s−1)
ρ /(Kg·m−3)
u /(m·s−1)
ρ /(Kg·m−3)
u /(m·s−1)
ρ /(Kg·m−3)
u /(m·s−1)
ρ /(Kg·m−3)
{Quinoline (1) + o-xylene (2)}
0.0000
1338.75
870.70
1315.00
869.40
1297.50
867.70
1278.15
865.90
0.1022
1384.84
901.40
1368.21
896.79
1357.89
893.69
1348.42
891.31
0.2039
1404.42
922.99
1386.95
919.02
1376.84
915.51
1366.21
911.50
0.3051
1424.21
942.22
1408.89
936.59
1399.42
932.06
1387.95
929.86
0.4058
1444.32
961.85
1430.84
956.70
1422.53
952.25
1411.02
948.11
0.5060
1465.26
981.69
1453.95
977.92
1445.79
974.98
1436.16
967.28
0.6058
1484.84
1001.73
1475.37
998.64
1469.05
995.28
1460.42
990.71
0.7050
1504.47
1027.16
1496.32
1022.00
1492.00
1018.22
1484.05
1013.23
0.8038
1523.58
1047.92
1517.95
1042.71
1513.47
1039.33
1506.68
1036.86
0.9021
1541.21
1067.14
1538.42
1063.23
1534.95
1060.07
1528.63
1057.61
1.0000
1553.68
1085.45
1550.68
1082.11
1547.37
1078.60
1541.05
1074.99
{Quinoline (1) + m-xylene (2)}
0.0000
1304.21
855.70
1285.27
848.70
1266.32
845.80
1244.21
840.50
0.1038
1375.05
887.18
1362.89
880.54
1354.74
875.63
1345.26
871.03
0.2067
1398.26
913.84
1384.79
910.65
1373.68
904.25
1361.05
900.75
0.3088
1420.05
931.94
1407.74
925.52
1395.26
921.60
1382.63
918.29
0.4100
1440.16
952.56
1428.68
945.83
1418.37
942.91
1406.89
940.30
0.5104
1461.95
978.74
1452.63
974.27
1443.47
969.91
1432.84
966.98
0.6099
1482.53
998.14
1474.35
996.30
1466.89
992.34
1457.26
989.29
0.7086
1502.32
1014.85
1495.16
1011.43
1488.84
1009.59
1479.89
1006.23
0.8066
1521.42
1043.74
1516.79
1038.14
1511.32
1034.56
1503.21
1031.79
0.9037
1532.89
1066.84
1529.26
1062.01
1525.79
1059.32
1519.47
1056.74
1.0000
1553.68
1085.45
1550.68
1082.11
1547.37
1078.60
1541.05
1074.99
{Quinoline (1) + p-xylene (2)}
0.0000
1288.43
852.80
1275.79
846.00
1253.68
843.00
1234.73
836.90
0.1041
1371.89
885.76
1361.74
878.51
1351.57
874.51
1342.10
869.20
0.2073
1395.10
909.41
1384.63
903.39
1375.52
901.61
1360.89
898.74
0.3095
1415.89
929.81
1406.57
918.62
1402.10
917.24
1389.47
915.55
0.4108
1436.00
949.85
1428.02
942.34
1424.21
938.40
1412.73
938.07
0.5112
1457.79
976.74
1451.47
971.93
1446.31
969.00
1434.68
965.25
0.6107
1480.37
997.73
1473.89
995.26
1472.73
991.22
1463.10
988.58
0.7093
1500.15
1013.63
1494.50
1010.43
1493.68
1009.37
1484.73
1005.40
0.8071
1518.26
1043.03
1514.63
1037.13
1509.16
1033.54
1501.05
1030.18
0.9040
1530.73
1066.53
1527.10
1061.60
1522.63
1058.00
1515.31
1056.23
1.0000
1553.68
1085.45
1550.68
1082.11
1547.37
1078.60
1541.05
1074.99Table 3
Coefficients of Redlich-Kister equation (Ai) and standard deviations (σ) for excess adiabatic compressibility (βE), excess intermolecular free length (LfE), excess acoustic impedance (ZE), and excess ultrasonic velocity (uE) for binary liquid mixtures.
Properties
T/K
A
0
A
1
A
2
σ
{Quinoline(1) + o-xylene (2)}
10−11βE/(m2·N−1)
303.15
−14.2750
15.7470
−19.3987
0.6231
308.15
−28.7822
50.6552
−42.1525
2.1127
313.15
−17.6239
21.2062
−27.0003
0.9585
318.15
−18.7916
26.9112
−35.7657
1.2192
10−4LfE/(m)
303.15
−15.4753
18.3256
−25.1069
0.7669
308.15
−17.0736
20.3448
−29.2354
0.9519
313.15
−18.8797
24.2345
−34.6635
1.1721
318.15
−19.8516
30.8846
−45.9429
1.4765
104ZE/(Kg·m2·s−1)
303.15
3.8618
−13.7678
27.2629
0.6353
308.15
3.3493
−12.9783
28.4726
0.7100
313.15
3.7404
−14.2036
31.6728
0.8641
318.15
1.8696
−17.0587
42.6292
0.9230
u
E/(m·s−1)
303.15
72.2489
−105.2525
169.0334
5.2762
308.15
80.2265
−123.8911
219.0926
6.9440
313.15
89.2298
−154.6148
264.9103
8.2814
318.15
102.3393
−204.3521
328.8972
11.0408
{Quinoline(1) + m-xylene (2)}
10−11βE/(m2·N−1)
303.15
−21.9058
31.4522
−26.7769
1.1162
308.15
−24.3389
36.3768
−31.2803
1.3641
313.15
−26.3980
42.3813
−39.2213
1.7172
318.15
−30.0673
51.5898
−49.7464
2.1494
10−4LfE/(m)
303.15
−24.3607
37.6519
−32.0435
1.3789
308.15
−26.8359
43.2278
−37.1303
1.6805
313.15
−28.8479
49.9906
−46.9235
2.0995
318.15
−32.7902
60.3208
−59.4502
2.5997
104ZE/(Kg·m2·s−1)
303.15
10.0579
−27.656
25.6108
1.0966
308.15
10.5394
−30.9755
26.8524
1.3238
313.15
10.1966
−32.6801
33.4784
1.4769
318.15
11.9598
−37.0021
41.4323
1.6993
u
E/(m·s−1)
303.15
127.5056
−281.9268
210.6969
11.5612
308.15
134.0042
−310.4828
252.1364
13.3956
313.15
142.3595
−363.6245
328.7575
16.7309
318.15
157.3428
−427.7324
412.1425
20.2179
{Quinoline(1) + p-xylene (2)}
10−11βE/(m2·N−1)
303.15
−24.3371
40.1603
−34.8069
1.4993
308.15
−26.1737
42.5118
−35.8559
1.7109
313.15
−30.5317
50.6633
−42.1002
1.9289
318.15
−33.3037
58.4176
−51.3519
2.2552
10−4LfE/(m)
303.15
−26.8705
48.104
−41.4238
1.8424
308.15
−28.7822
50.6552
−42.1525
2.1127
313.15
−33.8045
59.9962
−48.8655
2.3611
318.15
−36.5393
68.562
−59.8297
2.7239
104ZE/(Kg·m2·s−1)
303.15
10.6611
−35.6773
32.3543
1.4669
308.15
10.9532
−36.633
29.7221
1.7861
313.15
13.5849
−41.1183
31.3799
1.8255
318.15
14.1107
−43.7213
39.128
1.8140
u
E/(m·s−1)
303.15
143.0469
−360.5048
271.5399
14.6146
308.15
148.7841
−368.4327
277.8589
15.3763
313.15
179.5480
−431.3940
319.9555
17.7116
318.15
184.2120
−485.6012
383.7827
21.1574(a) Plot of excess adiabatic compressibility (βE) versus mole fraction (x1) for binary liquid mixtures of quinoline with o-xylene at temperatures: ♦, 303.15 K; □, 308.15 K; ▴, 313.15 K; ×, 318.15 K. (b) Plot of excess adiabatic compressibility (βE) versus mole fraction (x1) for binary liquid mixtures of quinoline with m-xylene at temperatures: ♦, 303.15 K; □, 308.15 K; ▴, 313.15 K; ×, 318.15 K. (c) Plot of excess compressibility (βE) versus mole fraction (x1) for binary liquid mixtures of quinoline with p-xylene at temperatures: ♦, 303.15 K; □, 308.15 K; ▴, 313.15 K; ×, 318.15 K.
(a)
(b)
(c)(a) Plot of excess free length (LfE) versus mole fraction (x1) for binary liquid mixtures of quinoline with o-xylene at temperatures: ♦, 303.15 K; □, 308.15 K; ▴, 313.15 K; ×, 318.15 K. (b) Plot of excess free length (LfE) versus mole fraction (x1) for binary liquid mixtures of quinoline with m-xylene at temperatures: ♦, 303.15 K; □, 308.15 K; ▴, 313.15 K; ×, 318.15 K. (c) Plot of excess free length (LfE) versus mole fraction (x1) for binary liquid mixtures of quinoline with p-xylene at temperatures: ♦, 303.15 K; □, 308.15 K; ▴, 313.15 K; ×, 318.15 K.
(a)
(b)
(c)(a) Plot of excess acoustic impedance (ZE) versus mole fraction (x1) for binary liquid mixtures of quinoline with o-xylene at temperatures: ♦, 303.15 K; □, 308.15 K; ▴, 313.15 K; ×, 318.15 K. (b) Plot of excess acoustic impedance (ZE) versus mole fraction (x1) for binary liquid mixtures of quinoline with m-xylene at temperatures: ♦, 303.15 K; □, 308.15 K; ▴, 313.15 K; ×, 318.15 K. (c) Plot of excess acoustic impedance (ZE) versus mole fraction (x1) for binary liquid mixtures of quinoline with p-xylene at temperatures: ♦, 303.15 K; □, 308.15 K; ▴, 313.15 K; ×, 318.15 K.
(a)
(b)
(c)(a) Plot of excess ultrasonic velocity (uE) versus mole fraction (x1) for binary liquid mixtures of quinoline with o-xylene at temperatures: ♦, 303.15 K; □, 308.15 K; ▴, 313.15 K; ×, 318.15 K. (b) Plot of excess ultrasonic velocity (uE) versus mole fraction (x1) for binary liquid mixtures of quinoline with m-xylene at temperatures: ♦, 303.15 K; □, 308.15 K; ▴, 313.15 K; ×, 318.15 K. (c) Plot of excess ultrasonic velocity (uE) versus mole fraction (x1) for binary liquid mixtures of quinoline with p-xylene at temperatures: ♦, 303.15 K; □, 308.15 K; ▴, 313.15 K; ×, 318.15 K.
(a)
.
(b)
(c)The excess transport properties of the mixtures are influenced by three main types of contributions, namely, (i) due to non specific Van der Waals type forces, (ii) due to hydrogen bonding, dipole-dipole, and donor-acceptor interaction between unlike molecules, and (iii) due to the fitting of smaller molecules into the voids created by the bigger molecules. The first effect leads to contraction in volume hence leads to negative contribution towardsuE and positive contribution towards βE. However, the second effect leads to negative contribution towards βE and positive contribution towards uE.For all the three mixtures, the results of the excess adiabatic compressibilityβE plotted in Figures 1(a)–1(c) are negative at all the temperatures studied. The negative values of βE suggest that the mixtures are less compressible than the corresponding ideal mixture. According to Fort and Moore [14], the liquids of different molecular size usually mix with decrease in volume yielding negative βE values. The strength of the interactions between component molecules increases when excess values tend to become increasingly negative. As the temperature increases, the βE values also increase in all the three systems, suggesting that the thermal energy activates the molecules towards complex formation between unlike molecules [15]. It is also observed that the molecular interactions are stronger in quinoline + o-xylene mixture.From Figures2(a)–2(c) it is observed that LfE values are negative for the entire mole fraction range, for all the four temperatures in case of all the three mixtures. The LfE values are increasingly negative as the strength of interaction between component molecules increases [16].The excess values ofZE which are plotted in Figures 3(a)–3(c) are all positive in all the three liquid systems over the entire composition range and for all the four temperatures studied. The positive excess values of ZE clearly suggest that there exist strong molecular interactions between the molecules of all the three mixtures [17].The results for the excess ultrasonic velocityuE plotted in Figures 4(a)–4(c) are positive for all the three mixtures at all the temperatures studied. The positive values of uE increase with the increase in temperature which indicates the increase in strength of interaction with temperature in all the three mixtures. The higher positive values of uE are observed in case of quinoline + o-xylene mixture, because the –OH group attached to the benzene ring in case of o-xylene is stabilized to a great extent through resonance as compared to other mixtures [18].


## 5. Conclusions

From the data of ultrasonic velocity and density, some thermoacoustical parameters and their excess parameters for the three binary liquid mixtures of quinoline with o-xylene, m-xylene, and p-xylene atT = 303.15, 308.15, 313.15, and 318.15 K are calculated for the entire composition range. From the results of these excess parameters, it is observed that there exists a strong molecular interaction between the unlike molecules in all the three mixtures. The interaction is stronger in case of quinoline + o-xylene mixture as compared to quinoline + m-xylene/p-xylene mixtures. These data will be useful in pharma and perfume industries for handling and mixing processes.



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*Source: 324098-2012-10-11.xml*