CHAPTER � 8

Influence of temperature on thermodynamic and transport properties of acid- base liquid

mixtures: an ultrasonic, volumetric and viscometric study

Influence of temperature on thermodynamic and transport

properties of acid- base liquid mixtures: an ultrasonic, volumetric

and viscometric study

8.1 Introduction

Studies on liquid mixtures using thermodynamic and transport properties

enables much information about the molecular interactions exist in the liquid

mixtures. The present work supplements the further investigations of molecular

interactions in the mixtures containing commercially important alcohols like

isopropyl/isobutyl/isoamyl alcohols and ethanol that are mixed in equimolar ratio.

Further such equimolar mixtures of ethanol + isopropyl alcohol/isobutyl

alcohol/isoamyl alcohols and N,N-dimethyl acetamide were added. The study of

thermodynamic and transport properties of these multi component liquid mixtures

and data on the analysis in terms of various models are important for industrial

and pharmaceutical applications1-6 such as solvents for gums, oils, alkaloids, urea

resins, for milk testing and for fibers.

A literature survey reveals that Liisa Pikka Rainen7 and Jan Zielkeiwicz8

reported density and viscosity data for binary mixtures of N, N-dimethyl acetamide

as one component aliphatic alcohols is another component at 303.15 K. Amalendu

Pal and Rakesh Kumar Bhardwaj9 also reported densities and viscosities for the

binary mixtures N,N-dimethyl acetamide with 2�propoxy ethanol and 2-isopropoxy

ethanol at 298.15 K. Density and viscosity data in the mixtures of N, N�dimethyl

acetamide with diethyl carbonate and dimethyl carbonate at 298.15 K were

reported by Iloukhani et al10. Rafiqul Islam and Quadri11 reported density and

viscosity of binary mixtures of benzyl alcohol with isoamyl alcohol and isopropyl

alcohol. Sravana kumar et al12 reported densities and viscosities of mixtures of 2-

chloroaniline with equimolar mixture of methanol and isopropanol/isobutanol at

308.15 K.

In this chapter, we have reported the ultrasonic, volumetric and viscometric

studies of molecular interactions at three different spot temperatures T = (308.15,

313.15 and 318.15) K in equimolar mixture of ethanol and isopropyl

alcohol/isobutyl alcohol/isoamyl alcohol as one component and N,N-dimethyl

acetamide as other component.

The deviation in ultrasonic velocity (∆u), excess molar volume ( EVm ),

deviation in isentropic compressibility (∆ks), excess inter molecular free length

( ELf ), excess acoustic impedance (ZE), deviation in viscosity ( ), and excess

Gibb�s free energy of activation of viscous flow ( *EÄG ) are calculated using the

experimental results of ultrasonic velocity (u), density (ñ) and viscosity (ç). The

variation of these properties over the entire composition range yields the

information about molecular interaction in the liquid systems. The excess/deviation

properties are fitted to Redlich-Kister type polynomial equation. Besides, the

experimental values of ultrasonic velocity for all the liquid mixtures measured and

compared with the theoretically estimated values using different empirical relations

such as Nomoto�s, Van Dael and Vangeel�s ideal mixing relation, Junjie�s relation.

The percentage deviations of theoretical velocities from experimental values are

calculated. The deviation of ultrasonic velocity from its experimental value is

further utilized to study molecular interactions. The experimental data of viscosity is

used to test the applicability of empirical relations of Gruenberg-Nissan, Hind-

McLaughlin, Katty-Chaudhary and Heric-Brewer for the systems studied.

8.2 Experimental

Ethanol�absolute (mass fraction purity 0.99) changshu yang yuan

chemicals � China make and N,N-dimethyl acetamide (mass fraction purity 0.99),

isopropyl alcohol (mass fraction purity 0.99), isobutyl alcohol (mass fraction purity

0.99), isoamyl alcohol (mass fraction purity 0.99) used in the present study are

Graded Reagent (G.R) obtained from LOBA Chemicals, Mumbai, INDIA.

Equimolar mixture of ethanol (EOH) and isopropyl alcohol (IPA)/isobutyl alcohol

(IBA)/isoamyl alcohol (IAA) is first prepared and this solution has been used to

prepare the liquid mixtures with N,N-dimethyl acetamide (DMA) so that over the

entire composition range covered (i.e 0-100% of DMA). The weighing of solutions

has been made using a METTLER TOLEDO (Switzerland make) ABB5-S/FACT

digital balance with an accuracy of 0.01 mg.

8.3 Results

The experimentally measured values of ultrasonic velocity, u, density, ñ and

viscosity, ç with mole fraction of DMA for three systems, (EOH+IPA)+DMA,

(EOH+IBA)+DMA and (EOH+IAA)+DMA are reported in Tables 8.1.A � 8.1.C

respectively. From these tables it has been observed that u and ñ increase linearly

and ç decreases non-linearly at all temperatures in the systems investigated.

The deviation in ultrasonic velocity (∆u), excess molar volume ( EVm ),

deviation in isentropic compressibility (∆ks), excess inter molecular free length

Table 8.1.A Experimental results of ultrasonic velocity (u), density (ñ) and viscosity (ç) for (EOH+IPA)+DMA system with mole fraction (x) of DMA at T = (308.15, 313.15 and 318.15) K

T = 308.15 K T = 313.15 K T = 318.15 K x u/ ñ/ ç/ u/ ñ/ ç/ u/ ñ/ ç/ m.s-1 kg.m-3 10-3 N.s.m-2 m.s-1 kg.m-3 10-3 N.s.m-2 m.s-1 kg.m-3 10-3 N.s.m-2

0.0000 1108.62 773.62 1.1862 1091.98 769.87 1.0663 1076.53 764.92 0.9542

0.0750 1143.50 792.30 1.0518 1122.93 783.97 0.9512 1104.98 764.81 0.8550

0.2350 1206.94 823.49 0.9337 1182.48 810.85 0.8424 1162.72 786.74 0.7490

0.3344 1242.50 840.80 0.8933 1215.99 826.97 0.8071 1195.78 801.30 0.7205

0.4279 1273.55 855.70 0.8673 1245.58 841.01 0.7861 1224.52 816.20 0.7063

0.5252 1302.23 870.30 0.8469 1275.02 854.80 0.7687 1252.85 831.42 0.6958

0.6300 1330.96 884.60 0.8309 1305.28 870.30 0.7595 1283.22 847.70 0.6909

0.7693 1367.21 902.20 0.8176 1344.46 890.00 0.7552 1322.84 869.20 0.6896

0.8686 1393.05 913.75 0.8194 1372.20 903.30 0.7632 1351.51 887.50 0.6982

0.9143 1404.60 918.78 0.8204 1385.17 910.07 0.7662 1365.23 898.00 0.7026

1.0000 1425.16 927.70 0.8279 1410.30 923.11 0.7721 1391.30 917.65 0.7090

Table 8.1.B Experimental results of ultrasonic velocity (u), density (ñ) and viscosity (ç) for (EOH+IBA)+DMA system with mole fraction (x) of DMA at T = (308.15, 313.15 and 318.15) K

T = 308.15 K T = 313.15 K T = 318.15 K x u/ ñ/ ç/ u/ ñ/ ç/ u/ ñ/ ç/ m.s-1 kg.m-3 10-3 N.s.m-2 m.s-1 kg.m-3 10-3 N.s.m-2 m.s-1 kg.m-3 10-3 N.s.m-2

0.0000 1139.46 782.14 1.5984 1134.85 780.18 1.4792 1111.23 775.12 1.3076

0.0687 1170.72 797.14 1.2707 1159.86 792.50 1.1723 1135.38 783.50 1.0485

0.1604 1203.45 816.25 1.1350 1192.03 810.80 1.0368 1167.72 796.00 0.9090

0.2520 1234.25 834.10 1.0489 1220.76 827.72 0.9550 1196.80 810.89 0.8398

0.3312 1260.49 847.54 0.9920 1244.08 840.59 0.9080 1220.83 823.10 0.8030

0.4118 1285.95 859.92 0.9448 1266.86 852.66 0.8689 1242.90 834.70 0.7750

0.5406 1321.60 878.70 0.8890 1300.46 870.70 0.8260 1276.57 854.36 0.7450

0.6697 1351.40 896.00 0.8651 1332.07 887.54 0.8044 1308.50 874.12 0.7230

0.7645 1372.30 907.70 0.8474 1354.09 899.22 0.7870 1331.44 886.26 0.7130

0.8754 1396.27 920.00 0.8291 1379.85 911.51 0.7733 1359.13 900.80 0.7093

1.0000 1425.16 927.70 0.8279 1410.30 923.11 0.7721 1391.30 917.65 0.7090

Table 8.1.C Experimental results of ultrasonic velocity (u), density (ñ) and viscosity (ç) for (EOH+IAA)+DMA system with mole fraction (x) of DMA at T = (308.15, 313.15 and 318.15) K

T = 308.15 K T = 313.15 K T = 318.15 K x u/ ñ/ ç/ u/ ñ/ ç/ u/ ñ/ ç./ m.s-1 kg.m-3 10-3 N.s.m-2 m.s-1 kg.m-3 10-3 N.s.m-2 m.s-1 kg.m-3 10-3 N.s.m-2

0.0000 1162.12 789.62 1.7469 1142.12 783.89 1.5185 1128.30 780.04 1.3721

0.0941 1204.10 817.12 1.3980 1181.21 808.65 1.2120 1164.34 796.50 1.1300

0.1874 1237.05 835.00 1.2440 1213.27 827.14 1.0950 1194.94 811.77 1.0000

0.2810 1266.82 850.50 1.1417 1242.48 843.04 1.0142 1223.78 826.57 0.9248

0.3795 1296.59 865.91 1.0630 1271.80 858.64 0.9502 1251.67 841.71 0.8690

0.4785 1321.55 880.67 1.0008 1297.18 873.26 0.9020 1276.49 856.07 0.8218

0.5689 1342.45 893.39 0.9600 1317.96 886.10 0.8690 1297.23 868.84 0.7922

0.6801 1366.85 908.06 0.9171 1343.50 900.00 0.8328 1322.11 883.74 0.7665

0.7834 1388.88 919.72 0.8815 1366.21 909.70 0.8067 1344.43 896.11 0.7428

0.8914 1410.07 928.50 0.8431 1389.79 916.38 0.7860 1368.20 907.00 0.7270

1.0000 1425.16 927.70 0.8279 1410.30 923.11 0.7721 1391.30 917.65 0.7090

( ELf ), excess acoustic impedance (ZE), deviation in viscosity ( ), and excess

Gibb�s free energy of activation of viscous flow ( *EÄG ) are calculated from the

experimental values of u, ñ and ç using the equations described in chapter 3.

The deviation/excess properties like ∆u, ELf , ZE, Äç and ÄG*E with mole

fraction of DMA at all temperatures for all the systems are presented in

Tables 8.2.A � 8.2.C. The variation of EVm with mole fraction of DMA at all

temperatures for all the systems is shown in figures 8.1 � 8.3. Where as the

figures 8.4 � 8.6 represent the variation of ∆ks with volume fraction of DMA at

all temperatures for all the systems respectively.

The values of Äu, Äks, EVm , Äç and ÄG*E are fitted to Redlich-Kister

type polynomial equation13,14 3.16. The co-efficients in the Redlich-Kister

polynomial and the corresponding standard deviations calculated using the

equation 3.17 are compiled in Table 8.3.

8.4 Discussion

From figures 8.1 � 8.3 it is observed that (a) EVm are negative at T =

308.15 K and positive at 313.15 K, 318.15 K for (EOH+IPA)+DMA mixture (b)

for (EOH+IBA)+DMA mixture EVm are negative at T = 308.15 K, 313.15 K

and positive at 318.15 K (c) excess molar volumes are negative for

(EOH+IAA)+DMA mixture at all temperatures respectively. As the

temperature increases, it has been observed that, the negative EVm values

Table 8.2.A Calculated properties of deviation in ultrasonic velocity, Äu,

excess intermolecular free length, ELf , excess acoustic impedance, ZE,

deviation in viscosities, Äç, and excess Gibb�s free energy of activation

of viscous flow, ÄG*E with mole fraction of DMA, x for (EOH+IPA)+DMA

system at T = (308.15, 313.15 and 318.15) K

x Ô Äu/ ELf / ZE/ Äç/ ÄG*E/

m.s-1 10-10m 106kg.m-2.s-1 10-3N.s.m-2 kJ.mol-1 T = 308.15 K 0.0000 0.0000 0.00 0.0000 0.0000 0.0000 0.0000 0.0750 0.0746 11.15 -0.0138 0.0135 -0.1075 -0.2400 0.2350 0.2338 23.92 -0.0283 0.0271 -0.1683 -0.3861 0.3344 0.3326 28.04 -0.0321 0.0317 -0.1731 -0.4031 0.4279 0.4258 29.50 -0.0329 0.0334 -0.1656 -0.3893 0.5252 0.5229 27.36 -0.0307 0.0317 -0.1511 -0.3596 0.6300 0.6277 22.93 -0.0262 0.0271 -0.1296 -0.3124 0.7693 0.7674 15.08 -0.0179 0.0185 -0.0930 -0.2299 0.8686 0.8672 9.50 -0.0110 0.0119 -0.0556 -0.1380 0.9143 0.9133 6.57 -0.0075 0.0082 -0.0382 -0.0960 1.0000 1.0000 0.00 0.0000 0.0000 0.0000 0.0000 T = 313.15 K 0.0000 0.0000 0.00 0.0000 0.0000 0.0000 0.0000 0.0750 0.0751 7.09 -0.0100 0.0051 -0.0930 -0.2206 0.2350 0.2363 15.68 -0.0218 0.0097 -0.1548 -0.3778 0.3344 0.3365 17.57 -0.0248 0.0107 -0.1608 -0.3978 0.4279 0.4311 17.40 -0.0250 0.0095 -0.1543 -0.3827 0.5252 0.5297 15.85 -0.0233 0.0070 -0.1431 -0.3566 0.6300 0.6349 12.76 -0.0199 0.0047 -0.1215 -0.3048 0.7693 0.7741 7.60 -0.0134 0.0011 -0.0848 -0.2139 0.8686 0.8729 3.74 -0.0076 -0.0018 -0.0476 -0.1142 0.9143 0.9175 2.15 -0.0049 -0.0018 -0.0312 -0.0739 1.0000 1.0000 0.00 0.0000 0.0000 0.0000 0.0000 T = 318.15 K 0.0000 0.0000 0.00 0.0000 0.0000 0.0000 0.0000 0.0750 0.0765 4.86 -0.0026 -0.0124 -0.0808 -0.1664 0.2350 0.2420 12.20 -0.0129 -0.0153 -0.1476 -0.3482 0.3344 0.3451 14.00 -0.0159 -0.0169 -0.1517 -0.3608 0.4279 0.4415 13.31 -0.0167 -0.0180 -0.1430 -0.3393 0.5252 0.5413 11.00 -0.0155 -0.0199 -0.1296 -0.3059 0.6300 0.6479 8.39 -0.0130 -0.0212 -0.1088 -0.2518 0.7693 0.7879 4.16 -0.0077 -0.0223 -0.0760 -0.1672 0.8686 0.8832 1.59 -0.0040 -0.0177 -0.0430 -0.0845 0.9143 0.9243 0.91 -0.0027 -0.0119 -0.0274 -0.0523 1.0000 1.0000 0.00 0.0000 0.0000 0.0000 0.0000

Table 8.2.B Calculated properties of deviation in ultrasonic velocity, Äu,

excess intermolecular free length, ELf , excess acoustic impedance, ZE,

deviation in viscosities, Äç, and excess Gibb�s free energy of activation

of viscous flow, ÄG*E with mole fraction of DMA, x for (EOH+IBA)+DMA

system at T = (308.15, 313.15 and 318.15) K

x Ô Äu/ ELf / ZE/ Äç/ ÄG*E/

m.s-1 10-10m 106kg.m-2.s-1 10-3N.s.m-2 kJ.mol-1 T = 308.15 K 0.0000 0.0000 0.00 0.0000 0.0000 0.0000 0.0000 0.0687 0.0684 11.64 -0.0116 0.0124 -0.2748 -0.4781 0.1604 0.1591 18.16 -0.0201 0.0220 -0.3398 -0.6203 0.2520 0.2491 22.80 -0.0256 0.0297 -0.3553 -0.6739 0.3312 0.3271 26.41 -0.0286 0.0344 -0.3512 -0.6842 0.4118 0.4067 28.83 -0.0299 0.0372 -0.3363 -0.6722 0.5406 0.5340 27.69 -0.0282 0.0371 -0.2929 -0.6104 0.6697 0.6621 20.60 -0.0225 0.0311 -0.2173 -0.4622 0.7645 0.7567 14.42 -0.0171 0.0250 -0.1619 -0.3545 0.8754 0.8682 6.72 -0.0098 0.0162 -0.0948 -0.2220 1.0000 1.0000 0.00 0.0000 0.0000 0.0000 0.0000 T = 313.15 K 0.0000 0.0000 0.00 0.0000 0.0000 0.0000 0.0000 0.0687 0.0686 6.10 -0.0075 0.0052 -0.2584 -0.4872 0.1604 0.1597 13.00 -0.0162 0.0143 -0.3290 -0.6577 0.2520 0.2502 16.50 -0.0212 0.0201 -0.3460 -0.7204 0.3312 0.3287 18.00 -0.0233 0.0224 -0.3370 -0.7178 0.4118 0.4087 18.57 -0.0239 0.0233 -0.3190 -0.6946 0.5406 0.5368 16.70 -0.0221 0.0218 -0.2709 -0.6070 0.6697 0.6656 12.75 -0.0179 0.0179 -0.2012 -0.4568 0.7645 0.7604 8.66 -0.0136 0.0138 -0.1516 -0.3535 0.8754 0.8722 3.88 -0.0075 0.0078 -0.0870 -0.2108 1.0000 1.0000 0.00 0.0000 0.0000 0.0000 0.0000 T = 318.15 K 0.0000 0.0000 0.00 0.0000 0.0000 0.0000 0.0000 0.0687 0.0690 4.92 -0.0057 -0.0003 -0.2180 -0.4506 0.1604 0.1616 11.57 -0.0126 0.0016 -0.3026 -0.6637 0.2520 0.2538 14.99 -0.0174 0.0045 -0.3170 -0.7222 0.3312 0.3335 16.84 -0.0197 0.0060 -0.3063 -0.7112 0.4118 0.4149 16.32 -0.0199 0.0051 -0.2861 -0.6732 0.5406 0.5437 13.93 -0.0187 0.0048 -0.2390 -0.5750 0.6697 0.6717 9.70 -0.0153 0.0043 -0.1837 -0.4562 0.7645 0.7669 6.10 -0.0111 0.0011 -0.1370 -0.3432 0.8754 0.8773 2.74 -0.0060 -0.0006 -0.0743 -0.1860 1.0000 1.0000 0.00 0.0000 0.0000 0.0000 0.0000

Table 8.2.C Calculated properties of deviation in ultrasonic velocity, Äu,

excess intermolecular free length, ELf , excess acoustic impedance, ZE,

deviation in viscosities, Äç, and excess Gibb�s free energy of activation

of viscous flow, ÄG*E with mole fraction of DMA, x for (EOH+IAA)+DMA

system at T = (308.15, 313.15 and 318.15) K

x Ô Äu/ ELf / ZE/ Äç/ ÄG*E/

m.s-1 10-10m 106kg.m-2.s-1 10-3N.s.m-2 kJ.mol-1 T = 308.15 K 0.0000 0.0000 0.00 0.0000 0.0000 0.0000 0.0000 0.0941 0.0926 17.23 -0.0179 0.0282 -0.2624 -0.4317 0.1874 0.1835 25.64 -0.0257 0.0395 -0.3307 -0.5633 0.2810 0.2746 30.79 -0.0298 0.0462 -0.3470 -0.6082 0.3795 0.3705 34.65 -0.0321 0.0516 -0.3351 -0.6053 0.4785 0.4668 33.56 -0.0313 0.0527 -0.3063 -0.5719 0.5689 0.5550 30.69 -0.0290 0.0516 -0.2641 -0.5057 0.6801 0.6639 25.84 -0.0248 0.0485 -0.2049 -0.4089 0.7834 0.7667 20.69 -0.0197 0.0429 -0.1454 -0.3067 0.8914 0.8775 13.47 -0.0123 0.0311 -0.0846 -0.2003 1.0000 1.0000 0.00 0.0000 0.0000 0.0000 0.0000 T = 313.15 K 0.0000 0.0000 0.00 0.0000 0.0000 0.0000 0.0000 0.0941 0.0929 13.86 -0.0159 0.0216 -0.2363 -0.4541 0.1874 0.1840 20.89 -0.0238 0.0320 -0.2836 -0.5672 0.2810 0.2752 25.00 -0.0279 0.0379 -0.2946 -0.6074 0.3795 0.3713 27.91 -0.0302 0.0424 -0.2850 -0.6064 0.4785 0.4679 26.73 -0.0293 0.0429 -0.2594 -0.5688 0.5689 0.5563 23.27 -0.0268 0.0412 -0.2249 -0.5067 0.6801 0.6661 19.00 -0.0225 0.0373 -0.1781 -0.4178 0.7834 0.7709 14.00 -0.0166 0.0290 -0.1271 -0.3071 0.8914 0.8845 8.61 -0.0091 0.0158 -0.0671 -0.1639 1.0000 1.0000 0.00 0.0000 0.0000 0.0000 0.0000 T = 318.15 K 0.0000 0.0000 0.00 0.0000 0.0000 0.0000 0.0000 0.0941 0.0938 11.29 -0.0117 0.0100 -0.1797 -0.3501 0.1874 0.1865 17.35 -0.0183 0.0156 -0.2478 -0.5119 0.2810 0.2793 21.58 -0.0226 0.0200 -0.2610 -0.5576 0.3795 0.3767 23.56 -0.0247 0.0229 -0.2515 -0.5530 0.4785 0.4747 22.34 -0.0240 0.0229 -0.2330 -0.5296 0.5689 0.5642 19.31 -0.0219 0.0214 -0.2027 -0.4708 0.6801 0.6745 14.95 -0.0180 0.0186 -0.1546 -0.3654 0.7834 0.7782 10.10 -0.0131 0.0140 -0.1098 -0.2663 0.8914 0.8885 5.45 -0.0070 0.0073 -0.0540 -0.1289 1.0000 1.0000 0.00 0.0000 0.0000 0.0000 0.0000

-0.10

-0.05

0.00

0.05

0.10

0.15

0.20

0.25

0.30

0 0.2 0.4 0.6 0.8 1

/10

-5m

3 .mo

l -1

Mole fraction, x

Fig. 8.1 Variation of excess molar volume, EVm with mole fraction of DMA, x for (EOH+IPA)+DMA mixture at T = 308.15 K ( ), 313.15 K ( ) and 318.15 K ( )

-0.12

-0.1

-0.08

-0.06

-0.04

-0.02

0

0.02

0.04

0.06

0.08

0 0.2 0.4 0.6 0.8 1

Mole fraction, x

/10

-5m

3 .mo

l -1

Fig. 8.2 Variation of excess molar volume, EVm with mole fraction of DMA, x for (EOH+IBA)+DMA mixture at T = 313.15 K ( ), 313.15 K ( ) and 318.15 K ( )

-0.25

-0.2

-0.15

-0.1

-0.05

0

0 0.2 0.4 0.6 0.8 1

Mole fraction, x

/10

-5m

3 .mo

l -1

Fig. 8.3 Variation of excess molar volume, EVm with mole fraction of DMA, x for (EOH+IAA)+DMA mixture at T = 318.15 K ( ), 313.15 K ( ) and 318.15 K ( )

-1.2

-1

-0.8

-0.6

-0.4

-0.2

0

0 0.2 0.4 0.6 0.8 1

Volume fraction, Ö

Äk s

/10

-10 P

a-1

Fig. 8.4 Variation of deviation in isentropic compressibility, ∆ks with volume fraction of DMA, Ö for (EOH+IPA)+DMA mixture at T = 308.15 K ( ), 313.15 K ( ) and 318.15 K ( )

-1.2

-1

-0.8

-0.6

-0.4

-0.2

00 0.2 0.4 0.6 0.8 1

Volume fraction, Ö

Äk s

/10

-10 P

a-1

Fig. 8.5 Variation of deviation in isentropic compressibility, ∆ks with volume fraction of DMA, Ö for (EOH+IBA)+DMA mixture at T = 308.15 K ( ), 313.15 K ( ) and 318.15 K ( )

-1.2

-1

-0.8

-0.6

-0.4

-0.2

0

0 0.2 0.4 0.6 0.8 1

Volume fraction, Ö

Äk s

/10

-10 P

a-1

Fig. 8.6 Variation of deviation in isentropic compressibility, ∆ks with volume fraction of DMA, Ö for (EOH+IAA)+DMA mixture at T = 308.15 K ( ), 313.15 K ( ) and 318.15 K ( )

Table 8.3 Coefficients Ai of Redlich-Kister type polynomial equation and the corresponding Standard deviations (ó) of all the systems under investigation

property A0 A1 A2 A3 A4 ó

(EOH+IPA)+DMA

T = 308.15 K

Äu/m.s-1 112.98 48.57 -31.03 -8.39 63.06 0.17 Äks/10-10Pa-1 -4.1740 -1.8494 -0.2646 -0.4884 -1.1817 0.0040

EVm /10-5m3.mol-1 -0.1492 -0.0565 -0.0023 -0.1477 -0.2413 0.0008

Äç/10-3N.s.m-2 -0.6234 -0.2848 -0.2855 -0.4505 -0.3545 0.0018 ÄG*E/kJ.mol-1 -1.4779 -0.5906 -0.6796 -0.9650 -0.6893 0.0044

T = 313.15 K

Äu/m.s-1 65.42 39.91 -0.16 6.42 -2.05 0.03 Äks/ 10-10Pa-1 -3.3619 -1.5328 -0.5533 -0.3833 0.0359 0.0031

EVm /10-5m3.mol-1 0.2669 -0.0757 -0.0443 -0.1085 0.1331 0.0026

Äç/10-3N.s.m-2 -0.5856 -0.2641 -0.2468 -0.3962 -0.1908 0.0012 ÄG*E/kJ.mol-1 -1.4579 -0.6162 -0.6356 -0.9691 -0.2241 0.0038

T = 318.15 K

Äu/m.s-1 47.40 47.01 0.01 -16.44 -15.25 0.15 Äks/10-10Pa-1 -2.3587 -1.3159 0.3075 1.0125 1.1588 0.0084

EVm /10-5m3.mol-1 1.0196 -0.0454 0.6571 0.5488 0.4055 0.0068

Äç/10-3N.s.m-2 -0.5323 -0.3082 -0.3422 -0.2400 0.0523 0.0006 ÄG*E/kJ.mol-1 -1.2555 -0.8378 -0.8220 -0.3158 0.6575 0.0024 (EOH+IBA)+DMA T = 308.15 K

Äu/m.s-1 115.25 30.03 -90.82 47.18 132.77 0.33 Äks/10-10Pa-1 -3.7555 -1.3910 0.3561 -0.3709 -1.770 0.0058

EVm /10-5m3.mol-1 -0.4191 -0.0615 -0.3120 0.3438 0.0550 0.0016

Äç/10-3N.s.m-2 -1.2619 -0.6642 0.2233 -1.4133 -2.7465 0.0100 ÄG*E/kJ.mol-1 -2.5800 -1.1329 0.5830 -2.0644 -4.9414 0.0147 T = 313.15 K

Äu/m.s-1 69.96 35.41 0.35 9.67 -14.26 0.20 Äks/10-10Pa-1 -3.0662 -1.2980 -0.7080 0.1394 0.7479 0.0043

EVm /10-5m3.mol-1 -0.2437 -0.1001 -0.2727 0.2851 0.4562 0.0013

Äç/10-3N.s.m-2 -1.1729 -0.7052 -0.0530 -1.2723 -2.2105 0.0090 ÄG*E/kJ.mol-1 -2.5888 -1.4172 -0.0961 -1.9667 -3.9479 0.0148

T = 318.15 K

Äu/m.s-1 59.59 49.02 0.73 -17.41 -19.79 0.23 Äks/10-10Pa-1 -2.6903 -1.0606 -0.4494 0.1785 0.8837 0.0052

EVm /10-5m3.mol-1 0.2116 0.2093 -0.0382 -0.0516 0.4612 0.0044

Äç/10-3N.s.m-2 -1.0323 -0.6657 -0.4628 -1.1036 -1.1851 0.0353 ÄG*E/kJ.mol-1 -2.4582 -1.4272 -1.2574 -2.0883 -1.6580 0.0082 (EOH+IAA)+DMA T = 308.15 K

Äu/m.s-1 133.01 45.87 -2.94 -21.24 96.20 0.45 Äks/10-10Pa-1 -3.8360 -1.2732 -0.7594 -0.6490 -1.9330 0.0079

EVm /10-5m3.mol-1 -0.8788 0.1138 -0.5086 -0.2239 -0.8826 0.0013

Äç/10-3N.s.m-2 -1.1920 -0.7752 -0.3249 -0.8115 -1.3166 0.0031 ÄG*E/kJ.mol-1 -2.2353 -1.1725 -0.4380 -0.8964 -2.4620 0.0036 T = 313.15 K

Äu/m.s-1 104.54 50.92 -13.99 -15.25 72.53 0.42 Äks/10-10Pa-1 -3.7116 -1.3485 -0.5919 -0.8576 -0.8641 0.0064

EVm /10-5m3.mol-1 -0.8034 0.1085 -0.4538 -0.6967 0.2024 0.0012

Äç/10-3N.s.m-2 -1.0137 -0.5850 -0.3017 -0.9598 -1.1757 0.0051 ÄG*E/kJ.mol-1 -2.2330 -0.9731 -0.6331 -1.7491 -1.9357 0.0095 T = 318.15 K

Äu/m.s-1 87.43 50.86 -18.20 -10.31 42.36 0.27 Äks/10-10Pa-1 -3.1218 -1.2018 -0.2633 -0.2098 -0.4061 0.0050

EVm /10-5m3.mol-1 -0.2920 0.1244 -0.1467 -0.1557 0.1963 0.0011

Äç/10-3N.s.m-2 -0.9002 -0.5851 -0.3942 -0.5639 -0.4078 0.0017 ÄG*E/kJ.mol-1 -2.0505 -1.0942 -0.7304 -0.9696 -0.4641 0.0057

are found to decrease. The above EVm values indicate that strong specific

interactions are predominant in the mixtures rather than dispersion forces.

The deviation in isentropic compressibility, ∆ks (see figures 8.4 � 8.6) values

are negative for all the systems at investigated temperatures, this indicate

the strong interactions are found to exist in the mixtures.

The sign of EVm depends upon the relative magnitude of expansion

and contractions of liquids during mixing process. The factors that mainly

responsible for the expansion of volume leads to the positive values of EVm

are (i) Breaking of one or both of the components in a mixture (ii) The

geometry of molecular structure which does not favor fitting of the molecules

of one component in to the voids created by another molecule of second

component in the mixture due to considerable change in molar volumes (iii)

Steric hindrance of the constituent molecules. The negative values of EVm

are due to strong specific interactions such as (iv) Chemical interaction

between constituent molecules such as formation of H-bond (v) Association

through weaker physical forces such as dipolar force (vi) Accommodation of

one component molecules into the interstitial positions of the structural

network of other component molecules. In the investigation of present

systems the observed EVm values can be ascribed to the dipole-dipole

interactions, H-bond formation between alcohol and amide molecules and

geometrical fitting of molecules of one component into the voids created by

the molecules of other component.

Alcohol molecules are self associated liquid molecules through inter

and intra molecular H-bonding15-17. N,N-dimethylacetamide has no significant

intermolecular hydrogen bond18,19 but it possesses highly polar in nature with

larger percentage of ionic character20 making oxygen of the carbonyl group

(C = O) of amide molecules is strong negative. As a result of above, it is

reasonable to exist the hydrogen bond ( >C=O�.H-O) between the oxygen

atom on the carbonyl group (C = O) of amide molecules and hydrogen atom

(O-H) of alcohol molecules. The observed negative values of EVm and ∆ks

suggest that the interaction between alcohol and amide molecules are

predominant than those between alcohol molecules. Such interactions may

be considered as reaction between alcohol molecules and amide molecules

as Lewis acid-base interaction. The addition of amide molecules to the

alcohol molecules can disrupt the associated structures and it causes the

free alcohol molecules which interact through dipole-dipole interactions

because the dipole moments of EOH,IPA,IBA and DMA molecules are 1.69,

1.56, 2.75 and 3.7 respectively ( all expressed in Debye units) besides to the

formation of hydrogen bond between alcohol and amide molecules.

On the examination of EVm and ∆ks values it has been observed that

the interaction between secondary alcohols and amide molecules decreases

as we move from IPA to IAA due to increase of chain length. Generally, the

existence of hydrogen bond between oxygen of methyl alcohol and hydrogen

atom of secondary alcoholic groups gradually decreases due to the increase

of methylene (-CH2) groups in secondary alcohols (IPA-(CH3)2-CH-OH, IBA-

(CH3)2-CH-CH2-OH, IAA-(CH3)2-CH-CH2-CH2-OH) and steric crowding on �

OH group. Therefore, the reaction between amide and alcohol molecules

also decreases when we move from IPA to IAA. As the temperature

increases the interaction between amide and alcohol molecules decreases

and follows the order (308.15>313.15>318.15) K.

The values presented in tables 8.2A � 8.2C of ∆u and ZE are positive

and ELf ,Äç and ÄG*E are negative at all temperatures in the present

investigated systems. The observed positive values of ∆u, ZE and negative

values of ELf suggest that strong interactions exist in the liquid mixtures,

which further supports the conclusions drawn from EVm and ∆ks. Dispersion

forces are primarily responsible for the negative deviations21 in Äç. However,

the observed negative values in Äç are not only due to the dispersion forces

but also due to the difference in molar masses (difference in size of

molecules) of the components of liquid mixtures21,22. Such argument for

negative values of Äç was also reported by several researchers7,23-26. From

tables 8.2A � 8.2C it can be seen that Äç values are less negative as

temperature increases from 308.15 to 318.15 K. From the analysis of the

data obtained in the present systems it is concluded that the liquid mixtures

under investigation move towards ideal behavior (interaction decreases) as

the temperature increases. The ÄG*E values are negative; also support the

conclusions drawn from Äç.

Theoretical ultrasonic velocities are evaluated by considering DMA as

one component and (EOH+IPA/IBA/IAA) as the other component in the

mixture. The theories due to Nomoto27, Van Dael and Vangeel28 and Junjie29

are employed and percentage deviations are calculated. These values for the

mixtures (EOH+IPA)+DMA, (EOH+IBA)+DMA and (EOH+IAA)+DMA are

compiled in tables 8.4A � 8.4C respectively at all temperatures. The

percentage deviations shown in the above tables are very small. On

comparison, the Nomoto�s relation is found to give good estimate of

experimental values of sound velocities in all the systems at all temperatures.

The dynamic viscosities of the liquid mixtures are calculated using the

empirical relations such as Grunberg and Nissan30, Hind and Ubbelohde31

and Katti and Chaudari32. The theoretical values of viscosity of the liquid

mixtures calculated using these relations are reported in tables 8.5A � 8.5C

for all the systems at all temperatures. The terms G12, H12, and Wvis are

adjustable parameters representing the binary interactions. Table 8.6

presents the values of these interaction parameters along with the standard

deviations, ó. The estimated values of ó are smaller indicating that the

present mixtures viscosities are well correlated by all the four viscosity

models.

Conclusions

1. The ultrasonic velocities, densities and viscosities of liquid mixtures of

N,N-dimethyl acetamide with equimolar mixture of ethanol and

isopropyl alcohol/isobutyl alcohol/isoamyl alcohol are measured over

the entire composition range at T = (308.15, 313.15 and 318.15) K

and ∆u, ∆ks, Äç, EVm and ÄG*E have been calculated from these

values.

2. The values of ∆ks, Äç and ÄG*E are found to negative, ∆u are positive

at every temperature studied, indicating the presence of specific

interactions between amide and alcohol molecules. The reason for

existence of specific interactions is attributed to the formation of

hydrogen bond (>C=O�.H-O) between the oxygen atom on the

Table 8.4.A Theoretical ultrasonic velocities and corresponding percentage

deviations with mole fraction of DMA, x for (EOH+IPA)+DMA at T = (308.15,313.15

and 318.15) K

X UExp UN UV UJUN % UN % UV % UJUN

T = 308.15 K 0.0000 1108.62 1108.62 1108.62 1108.62 0.000 0.000 0.000 0.0750 1143.50 1137.86 1109.48 1125.95 -0.493 -2.975 -1.535 0.2350 1206.94 1196.83 1119.91 1166.21 -0.838 -7.211 -3.375 0.3344 1242.50 1231.20 1132.65 1193.41 -0.910 -8.841 -3.951 0.4279 1273.55 1262.10 1149.53 1220.59 -0.899 -9.738 -4.159 0.5252 1302.23 1292.88 1172.83 1250.59 -0.718 -9.937 -3.966 0.6300 1330.96 1324.51 1205.63 1284.90 -0.485 -9.417 -3.461 0.7693 1367.21 1364.32 1265.01 1334.00 -0.211 -7.475 -2.429 0.8686 1393.05 1391.24 1322.02 1371.61 -0.130 -5.099 -1.539 0.9143 1404.60 1403.26 1353.73 1389.75 -0.095 -3.622 -1.057 1.0000 1425.16 1425.16 1425.16 1425.16 0.000 0.000 0.000

T = 313.15 K 0.0000 1091.98 1091.98 1091.98 1091.98 0.000 0.000 0.000 0.0750 1122.93 1121.35 1092.97 1109.33 -0.141 -2.668 -1.211 0.2350 1182.48 1180.60 1103.62 1149.65 -0.159 -6.669 -2.776 0.3344 1215.99 1215.14 1116.46 1176.92 -0.070 -8.185 -3.213 0.4279 1245.58 1246.21 1133.41 1204.19 0.051 -9.005 -3.323 0.5252 1275.02 1277.16 1156.78 1234.32 0.168 -9.274 -3.192 0.6300 1305.28 1308.98 1189.65 1268.81 0.284 -8.859 -2.794 0.7693 1344.46 1349.05 1249.21 1318.25 0.341 -7.085 -1.950 0.8686 1372.20 1376.15 1306.46 1356.19 0.288 -4.790 -1.167 0.9143 1385.17 1388.25 1338.35 1374.50 0.222 -3.380 -0.770 1.0000 1410.30 1410.30 1410.30 1410.30 0.000 0.000 0.000

T = 318.15 K 0.0000 1076.53 1076.53 1076.53 1076.53 0.000 0.000 0.000 0.0750 1104.98 1105.55 1077.53 1093.65 0.052 -2.484 -1.025 0.2350 1162.72 1164.11 1088.08 1133.45 0.120 -6.419 -2.517 0.3344 1195.78 1198.26 1100.78 1160.38 0.207 -7.945 -2.960 0.4279 1224.52 1228.98 1117.53 1187.32 0.364 -8.737 -3.038 0.5252 1252.85 1259.59 1140.64 1217.10 0.538 -8.956 -2.854 0.6300 1283.22 1291.06 1173.13 1251.21 0.611 -8.579 -2.495 0.7693 1322.84 1330.70 1232.00 1300.13 0.594 -6.867 -1.717 0.8686 1351.51 1357.50 1288.60 1337.69 0.443 -4.654 -1.023 0.9143 1365.23 1369.48 1320.13 1355.83 0.311 -3.303 -0.689

1.0000 1391.30 1391.30 1391.30 1391.30 0.000 0.000 0.000

Table 8.4.B Theoretical ultrasonic velocities and corresponding percentage

deviations with mole fraction of DMA, x for (EOH+IBA)+DMA at T = 308.15,313.15

and 318.15) K

x UExp UN UV UJUN % UN % UV % UJUN

T = 308.15 K 0.0000 1139.46 1139.46 1139.46 1139.46 0.000 0.000 0.000 0.0687 1170.72 1161.48 1144.45 1152.97 -0.789 -2.244 -1.516 0.1604 1203.45 1190.30 1153.40 1172.22 -1.093 -4.159 -2.595 0.2520 1234.25 1218.41 1165.10 1192.83 -1.283 -5.603 -3.356 0.3312 1260.49 1242.19 1177.65 1211.82 -1.452 -6.572 -3.861 0.4118 1285.95 1265.93 1192.97 1232.33 -1.557 -7.231 -4.170 0.5406 1321.60 1302.82 1223.46 1267.66 -1.421 -7.426 -4.081 0.6697 1351.40 1338.63 1262.96 1306.58 -0.945 -6.544 -3.317 0.7645 1372.30 1364.20 1299.00 1337.61 -0.590 -5.341 -2.528 0.8754 1396.27 1393.34 1350.73 1376.83 -0.210 -3.262 -1.392 1.0000 1425.16 1425.16 1425.16 1425.16 0.000 0.0000 0.000

T = 313.15 K 0.0000 1134.85 1134.85 1134.85 1134.85 0.000 0.000 0.000 0.0687 1159.86 1156.17 1139.59 1148.07 -0.318 -1.748 -1.017 0.1604 1192.03 1184.05 1148.15 1166.86 -0.669 -3.681 -2.112 0.2520 1220.76 1211.22 1159.42 1186.93 -0.782 -5.025 -2.771 0.3312 1244.08 1234.19 1171.53 1205.39 -0.795 -5.832 -3.110 0.4118 1266.86 1257.09 1186.33 1225.27 -0.771 -6.357 -3.283 0.5406 1300.46 1292.66 1215.83 1259.44 -0.600 -6.508 -3.154 0.6697 1332.07 1327.14 1254.02 1296.94 -0.370 -5.859 -2.637 0.7645 1354.09 1351.73 1288.84 1326.74 -0.174 -4.819 -2.100 0.8754 1379.85 1379.74 1338.74 1364.27 -0.008 -2.979 -1.129 1.0000 1410.30 1410.30 1410.30 1410.30 0.000 0.000 0.000

T = 318.15 K 0.0000 1111.23 1111.23 1111.23 1111.23 0.000 0.000 0.000 0.0687 1135.38 1132.84 1116.13 1124.54 -0.224 -1.696 -0.955 0.1604 1167.72 1161.13 1124.91 1143.48 -0.564 -3.666 -2.076 0.2520 1196.80 1188.71 1136.39 1163.74 -0.676 -5.047 -2.762 0.3312 1220.83 1212.04 1148.69 1182.39 -0.720 -5.909 -3.148 0.4118 1242.90 1235.31 1163.70 1202.52 -0.611 -6.372 -3.249 0.5406 1276.57 1271.48 1193.58 1237.17 -0.399 -6.501 -3.086 0.6697 1308.50 1306.57 1232.27 1275.30 -0.148 -5.826 -2.537 0.7645 1331.44 1331.61 1267.59 1305.68 0.013 -4.797 -1.935 0.8754 1359.13 1360.15 1318.31 1344.06 0.075 -3.003 -1.109

1.0000 1391.30 1391.30 1391.30 1391.30 0.000 0.000 0.000

Table 8.4.C Theoretical ultrasonic velocities and corresponding percentage

deviations with mole fraction of DMA, x1for (EOH+IAA)+DMA at T = 308.15,313.15

and 318.15) K

x UExp UN UV UJUN % UN % UV % UJUN

T = 308.15 K 0.0000 1162.12 1162.12 1162.12 1162.08 0.000 0.000 0.000 0.0941 1204.10 1187.56 1173.40 1178.39 -1.374 -2.550 -2.135 0.1874 1237.05 1212.66 1186.49 1195.91 -1.972 -4.087 -3.326 0.2810 1266.82 1237.70 1201.70 1214.91 -2.299 -5.140 -4.098 0.3795 1296.59 1263.90 1220.20 1236.59 -2.521 -5.892 -4.626 0.4785 1321.55 1290.07 1241.70 1260.26 -2.382 -6.042 -4.638 0.5689 1342.45 1313.82 1264.21 1283.68 -2.133 -5.828 -4.378 0.6801 1366.85 1342.85 1296.26 1315.08 -1.756 -5.164 -3.788 0.7834 1388.88 1369.63 1331.15 1347.16 -1.386 -4.157 -3.004 0.8914 1410.07 1397.43 1373.99 1384.08 -0.896 -2.559 -1.843 1.0000 1425.16 1425.16 1425.16 1425.16 0.000 0.000 0.000

T = 313.15 K 0.0000 1142.12 1142.12 1142.12 1142.08 0.000 0.000 0.000 0.0941 1181.21 1167.95 1153.61 1158.48 -1.123 -2.337 -1.924 0.1874 1213.27 1193.45 1166.92 1176.12 -1.634 -3.820 -3.062 0.2810 1242.48 1218.92 1182.37 1195.31 -1.896 -4.838 -3.796 0.3795 1271.80 1245.59 1201.16 1217.25 -2.061 -5.554 -4.289 0.4785 1297.18 1272.27 1223.01 1241.26 -1.920 -5.718 -4.311 0.5689 1317.96 1296.49 1245.89 1265.07 -1.629 -5.468 -4.013 0.6801 1343.50 1326.12 1278.51 1297.11 -1.294 -4.837 -3.453 0.7834 1366.21 1353.48 1314.08 1329.95 -0.932 -3.816 -2.654 0.8914 1389.79 1381.91 1357.86 1367.89 -0.567 -2.298 -1.576 1.0000 1410.30 1410.30 1410.30 1410.30 0.000 0.000 0.000

T = 318.15 K 0.0000 1128.30 1128.30 1128.30 1128.25 0.000 0.000 0.000 0.0941 1164.34 1153.67 1139.57 1144.41 -0.916 -2.127 -1.712 0.1874 1194.94 1178.70 1152.63 1161.78 -1.359 -3.541 -2.775 0.2810 1223.78 1203.69 1167.79 1180.65 -1.642 -4.575 -3.524 0.3795 1251.67 1229.87 1186.24 1202.21 -1.742 -5.227 -3.952 0.4785 1276.49 1256.03 1207.68 1225.80 -1.603 -5.391 -3.971 0.5689 1297.23 1279.78 1230.13 1249.16 -1.345 -5.173 -3.706 0.6801 1322.11 1308.82 1262.13 1280.58 -1.005 -4.537 -3.141 0.7834 1344.43 1335.64 1297.02 1312.74 -0.654 -3.526 -2.357 0.8914 1368.20 1363.50 1339.93 1349.86 -0.344 -2.066 -1.340 1.0000 1391.30 1391.30 1391.30 1391.30 0.000 0.000 0.000

Table 8.5.A Calculated values of the viscosity (ç /10-3 N.s.m-2) from Eqs.

[(3.35) - (3.38)] with mole fraction of DMA, x for (EOH+IPA)+DMA at T =

(308.15,313.15 and 318.15) K

Mole fraction Grunberg Hind Katti (x) & & & Nissan Ubbelohde Chaudari

T = 308.15 K 0.0000 1.1862 1.1862 1.1862 0.0750 1.1000 1.1084 1.1025 0.2350 0.9613 0.9700 0.9618 0.3344 0.9003 0.9030 0.9000 0.4279 0.8571 0.8532 0.8562 0.5252 0.8249 0.8150 0.8239 0.6300 0.8035 0.7894 0.8023 0.7693 0.7946 0.7803 0.7936 0.8686 0.8014 0.7912 0.8008 0.9143 0.8083 0.8011 0.8080 1.0000 0.8279 0.8279 0.8279 T = 313.15 K 0.0000 1.0663 1.0663 1.0663 0.0750 0.9913 0.9986 0.9918 0.2350 0.8712 0.8788 0.8713 0.3344 0.8187 0.8214 0.8192 0.4279 0.7821 0.7792 0.7824 0.5252 0.7554 0.7476 0.7553 0.6300 0.7387 0.7275 0.7390 0.7693 0.7343 0.7231 0.7345 0.8686 0.7435 0.7356 0.7429 0.9143 0.7513 0.7457 0.7509 1.0000 0.7721 0.7721 0.7721 T = 318.15 K 0.0000 0.9542 0.9542 0.9542 0.0750 0.8881 0.8940 0.8796 0.2350 0.7826 0.7881 0.7809 0.3344 0.7370 0.7380 0.7385 0.4279 0.7055 0.7016 0.7098 0.5252 0.6832 0.6750 0.6887 0.6300 0.6700 0.6591 0.6754 0.7693 0.6689 0.6585 0.6714 0.8686 0.6795 0.6724 0.6803 0.9143 0.6877 0.6827 0.6887 1.0000 0.7090 0.7090 0.7090

Table 8.5.B Calculated values of the viscosity (ç /10-3 N.s.m-2) from Eqs.

[(3.35) - (3.38)] with mole fraction of DMA, x for (EOH+IBA)+DMA at T =

(308.15,313.15 and 318.15) K

Mole fraction Grunberg Hind Katti (x) & & & Nissan Ubbelohde Chaudari

T = 308.15 K 0.0000 1.5984 1.5984 1.5984 0.0687 1.4089 1.4351 1.4089 0.1604 1.2127 1.2423 1.2130 0.2520 1.0666 1.0788 1.0671 0.3312 0.9710 0.9608 0.9706 0.4118 0.8969 0.8629 0.8955 0.5406 0.8177 0.7531 0.8160 0.6697 0.7774 0.7005 0.7764 0.7645 0.7695 0.6986 0.7695 0.8754 0.7826 0.7356 0.7842 1.0000 0.8279 0.8279 0.8279 T = 313.15 K 0.0000 1.4792 1.4792 1.4792 0.0687 1.3012 1.3251 1.2994 0.1604 1.1176 1.1434 1.1179 0.2520 0.9814 0.9898 0.9828 0.3312 0.8928 0.8792 0.8937 0.4118 0.8245 0.7880 0.8249 0.5406 0.7523 0.6868 0.7521 0.6697 0.7167 0.6404 0.7166 0.7645 0.7111 0.6413 0.7113 0.8754 0.7260 0.6801 0.7263 1.0000 0.7721 0.7721 0.7721 T = 318.15 K 0.0000 1.3076 1.3076 1.3076 0.0687 1.1519 1.1734 1.1493 0.1604 0.9916 1.0154 0.9884 0.2520 0.8730 0.8822 0.8721 0.3312 0.7961 0.7867 0.7963 0.4118 0.7372 0.7082 0.7377 0.5406 0.6758 0.6222 0.6776 0.6697 0.6474 0.5845 0.6503 0.7645 0.6451 0.5877 0.6471 0.8754 0.6622 0.6247 0.6632 1.0000 0.7090 0.7090 0.7090

Table 8.5.C Calculated values of the viscosity (ç /10-3 N.s.m-2) from Eqs.

[(3.35) - (3.38)] with mole fraction of DMA, x for (EOH+IAA)+DMA at T =

(308.15,313.15 and 318.15) K

Mole fraction Grunberg Hind Katti (x) & & & Nissan Ubbelohde Chaudari

T = 308.15 K 0.0000 1.7469 1.7469 1.7469 0.0941 1.5032 1.5330 1.5116 0.1874 1.3166 1.3470 1.3188 0.2810 1.1717 1.1867 1.1684 0.3795 1.0550 1.0461 1.0488 0.4785 0.9670 0.9341 0.9602 0.5689 0.9075 0.8575 0.9016 0.6801 0.8572 0.7967 0.8541 0.7834 0.8300 0.7733 0.8300 0.8914 0.8199 0.7830 0.8227 1.0000 0.8279 0.8279 0.8279 T = 313.15 K 0.0000 1.5185 1.5185 1.5185 0.0941 1.3147 1.3400 1.3204 0.1874 1.1586 1.1851 1.1619 0.2810 1.0377 1.0521 1.0376 0.3795 0.9406 0.9360 0.9386 0.4785 0.8681 0.8443 0.8654 0.5689 0.8199 0.7823 0.8178 0.6801 0.7807 0.7344 0.7795 0.7834 0.7616 0.7182 0.7606 0.8914 0.7584 0.7302 0.7568 1.0000 0.7721 0.7721 0.7721 T = 318.15 K 0.0000 1.3721 1.3721 1.3721 0.0941 1.1967 1.2176 1.1967 0.1874 1.0610 1.0832 1.0606 0.2810 0.9549 0.9674 0.9543 0.3795 0.8690 0.8659 0.8685 0.4785 0.8040 0.7850 0.8036 0.5689 0.7603 0.7297 0.7603 0.6801 0.7238 0.6859 0.7244 0.7834 0.7050 0.6692 0.7057 0.8914 0.6998 0.6764 0.6998 1.0000 0.7090 0.7090 0.7090

Table 8.6 Various interaction parameters calculated from viscosity relations

and the corresponding standard deviations (ó/10-3 N.s.m-2)

G12 ó H12 ó Wvis/RT ó

(EOH+IPA)+DMA

T = 308.15 K -0.6991 0.0302 0.0006 0.0411 -0.6732 0.0315 T = 313.15 K -0.7022 0.0266 0.0006 0.0353 -0.6196 0.0268 T = 318.15 K -0.7143 0.0261 0.0005 0.0338 -0.5122 0.0227

(EOH+IBA)+DMA

T = 308.15 K -1.2668 0.0906 0.0004 0.1435 -1.3043 0.0910 T = 308.15 K -1.3074 0.0887 0.0003 0.1411 -1.3161 0.0883 T = 308.15 K -1.3251 0.0790 0.0003 0.1229 -1.2711 0.0767

(EOH+IAA)+DMA

T = 308.15 K -0.9381 0.0683 0.0005 0.1125 -1.0605 0.0725 T = 308.15 K -0.9438 0.0637 0.0005 0.0980 -1.0414 0.0667 T = 308.15 K -0.8758 0.0490 0.0005 0.0776 -0.9047 0.0487

carbonyl group of amide molecules (C = O) and hydrogen atom of hydroxyl

group (O-H) of alcohol molecules and dipole-dipole interactions. The

difference in molar masses of the liquid molecules is also responsible to the

existing specific interactions between the molecules of the component

liquids.

3. The interaction between the amide and alcohol molecules decreases as the

temperature increases in all the systems studied. The interactions follow the

order T = (308.15>313.15>318.15) K and DMA+,(EOH+IPA>EOH+IBA>

EOH+IAA).

4. Besides, the computed ultrasonic velocities from different velocity theories

are correlated with the experimentally measured values. Among these

theories, Nomoto�s relation gives the good agreement between the

theoretical and experimental ultrasonic velocity values.

5. The experimental viscosity values are compared with the viscosity values

obtained from different empirical relations and these are in good agreement

with the experimental values.

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Future plan of work

To understand the molecular interactions between substituted pyridine with

alkaline earth halides of ionic liquids (ILs), we measure the thermo physical

properties such as density (ñ), viscosity (ç) and ultrasonic velocity (u) over the

entire range of composition at different temperatures (30, 40 and 50 0C) under

atmospheric pressure. From these measured parameters excess molar volume

( EVm ), deviation in isentropic compressibility (Äks) and deviation in viscosity (Äç)

may be evaluated as a function of the concentration of IL. Further, these

parameters may be fitted to the Redlich � Kister type polynomial and the

corresponding standard deviations may be evaluated. The intermolecular

interactions and structural effects may be analysed based on the measured and

derived properties. A qualitative analysis of the results may be discussed in terms

of ion-dipole, ion-pair interactions and hydrogen bonding between ILs and

substituted pyridine molecules.