Study the Effect of Chemical Structures of Solvent on the
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Study the Effect of Chemical Structures of Solvent on the
Journal of A pplied Sciences Res earch, 5(6): 605-612, 2009 © 2009, INSInet Publication Study the Effect of Chemical Structures of Solvent on the Excess Free Energies of Solution Farid M. Farag and Sahar M. Taw fik Egyptian Petroleum Research Institute (EPRI), Cairo, Egypt. Abs tract: Vis cos ities and refractive indices of the mixtures of benzene with the s olvents Triethyleneglycol (TEG), Tetraethyleneglycol (TETEG), N-me t h y lpyrrolidone (NM P), Triethyleneglycol-dimethylether (T EGD M E), D ie t h y le n e g ly c o l-dimethylether (D EGD M E), D ime t h y lfo rma mid e (D M F ) a n d Dimethyls ulphoxide (DM SO) at 30o C and atmos pheric pres s ure have been meas ured at t h e entire compos ition range mixtures . Exces s free energies Ä GE and exces s refractive indices n ED were determined to unders tand the interaction patterns between molecules and the effect of the s tructure on it. The ÄGE are +ve for all s olvents with benzene except for the s olvents DM SO and DM F are –ve. For exce s s re fra ctive indices all are -ve deviation except of DEGDM E, DM SO and DM F are +ve. Key words : Exces s free energy, refractive index, kinematic vis cos ity, s olvents . INTRODUCTION Vis cometric properties of mixed s olvent s ys tems and their dependence on compos ition find applications in many important chemic a l, indus trial and biological proces s es . The s tudy of functions s uch as deviation in vis cos ity and exces s free energy of activation of vis cous flow, deviation in re fra ctive index, etc. of binary liquid mixtu re s are us eful in unders tanding the nature and s trength of molecular interaction between the component molecules [1-2]. Benzene is a non-polar and unas s ociated liquid w h e reas glycols are polar and s e lf-as s ociated through hydrogen bonding in the pure s tate. The mixtures are interes ting becaus e o f t he pos s ibility of weak hydro g e n bonding involving ðelectrons o f the benzene ring and the proton of the hydroxyl group of glycols . W eak hydrogen bonding of aromatic ring with proton donors appears to play an important rule in the s tructure of certain bimolecules [3 ,4 ] DM F is approtic and unas s ociate d in its pure liquid s tate [5]. It belongs to the s o-called s u per s olvents , owing to its mis c ib ility with all common polar and non-polar s olvents [6], probably to its high polarity with large dipole moment (µ = 3.8D) and moderately h igh dielectric cons tant (ª = 36.76) a t 298.15K. The s olvent DM SO was particularly chos e n due to its high polarity [7] . NM P is a heterocyclic polar s olvent u s ed for the extraction o f lo w mo le c u la r w e ig h t a romatic compounds from petroleum feed s tock [ 8 ]. The pres ent work is devoted to s tudy the exces s fre e energies ÄGE and exces s refra c t iv e index of the s olvents TEG, TEGD M E, T ET EG, DEGDM E, NM P, DM F and DM SO with benzene as aromatic hydro carbon mixtures Corresponding Author: where the s olvent cou ld b e us ed as s elective s olvents for aromatic hydrocarbons . In this s t u d y we us ed the data of vis cos ity and refractive ind e x which are publis hed before by us but not calculated for ÄGE or n ED. He re w e c ollect the data o f vis cos ity ç and refractive index n D [9 ,1 0 ] and calculate the ÄGE and n ED .The ÄGE for TETEG was calculated before but we us e it here for comparis on [1 1 ]. MATERIALS AND METHODS Experimental: The liquids us ed were of analytical grade and mixtures were prepared by mixing ca lc u lated volumes to get mixtures of different compos itions . The kinematics vis cos it y meas urements of pure liquids and their mixtures were made with an a u t o matic Schott Gerate A VS 400 vis cos ity meas uring s ys tem equipped with s eries of ubbelhode Vis cometers . Refractive indices are at th e s o dium D-line, n D was meas ured us ing a thermos t a t ed A bbe refractometer (carlizeis s , les s than ±0.0001 units ). RES ULTS AND DIS CUS S ION The exces s free energies for vis cous flow at 300 c were obtained [1 2 -1 5 ] by us ing the equation: Ä GE = RT [ ln( ç m Vm / h N A ) – hNA) ] i ln (ç i Vi / (1) W here R is the gas cons tant, T is the abs olute temperature, h is Plank's cons tant (6.626 x 103 4 J.S). Farid M . Farag, Egyptian Petroleum Research Institute, Cairo, Egypt. E-mail: [email protected] 605 J. App. Sci. Res., 5(6): 605-612, 2009 NA is A vogadro's number, ç m a n d Vm are the vis cos ity a n d t h e molar volume of the binary mixtu re res pective ly , ç i and Vi the vis cos ity and the molar volume of the ith pure components . F ig. (1) and Table (1) s how that the values of Ä GE are pos itive for all mixtu res over the entire compos ition range except that for DM F and DM SO are negative. The va lues are increas e in the s equence: TETEG > TEGDM E > TEG > DEGDM E > NM P > DM F > DM SO s ugges ts t h a t t h ey are attributed to the large s ize and cohes ive energy diffe re n c e between the two unlike components . From the me as ured refractive indices (n D) at 300 c t h e exces s refractive indices (n ED) were calculated us ing the equation: The negativity for all mixture in t h e s equence : NM P > TEGDM E > TETEG > DM F >T EG and the maximum negativity for n ED for all mixt u re is at x1 .0.4 except for NM P at x1 .0.85. In general, the magnitude of n ED increas es with decreas es in the s trength of interaction between the component mole c u le s in the mixture [1 6 ], it means more negative , more s trength of interaction. For ÄGE the maximum is a ls o at x1 .0.4 (it means that is the bes t concentration for extraction). A ccording to Reed and Taylor, Pos itive ÄGE values indicate s pecific interactions , while negative value s indicate the dominance of dis pers ion forces [1 7 ]. In th e p res ent work and in the work reported by others [1 8 ,1 9 ]. The mole fraction bas is has b e e n u s e d to calculate values . Thus , the functions ÄGE and truly complemen t each other in des cribing the behaviors of the pres ent binary liquid mixtures . (2) W here x1 , x2 , n 1 , n 2 are t h e molar fraction and refractive indices of the firs t and s econd s olvents in their mixtures res pectively and n m is the refractive index of the s olvent mixtures . F ig. (2) and Table (2) s how that the exc e s s re fra c t iv e indices are negative for all mixtures for the entire compos ition range except for DEGDM E has p o s itive deviation and DM SO has pos itive deviation tell x1 . 0.505 after that it going as negative. The exces s refractive indices n ED s how that s olvent-s olvent interaction proces s es depend on t h e nature of s olvent and on its phys ical properties s uch as the dielectric cons tant, dipole moment,and donor number, and it is indicates maximum s olvent -s o lvent interaction proces s es and s o define the s uitable s olvent mixture with the high effective properties [2 0 ]. Fig. 1: Exces s Free Energy ÄGE vs the M ole Fraction X1 of Benzene with Different Solvents . 606 J. App. Sci. Res., 5(6): 605-612, 2009 Table 1: Mole fractions (x 1 , x 2), kinematic viscosity (ç) at 30 oc and the excess free energy ÄG E of benzene with different solvents. Benzene+T EG X2 çm Vm ÄGE X1 1.0000 0.0000 24.3800 134.640 6.29E-09 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------0.8570 0.1430 18.0154 125.770 5.03E-01 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------0.7271 0.2729 11.7000 119.010 5.81E-01 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------0.4997 0.5003 5.1000 111.390 6.07E-01 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------0.3997 0.6003 3.4800 107.150 5.51E-01 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------0.3075 0.6925 2.5125 103.100 5.59E-01 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------0.2223 0.7777 1.8118 99.500 5.02E-01 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------0.1429 0.8571 1.2613 95.560 2.85E-01 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------0.0689 0.9310 0.8508 92.400 -4.18E-02 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------0.0000 1.0000 0.6581 92.514 -1.06E-08 Benzene+DMSO 1.0000 0.0000 1.7294 73.672 -8.53E-09 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------0.9185 0.0815 1.5100 75.118 -1.41E-01 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------0.7450 0.2551 1.2490 78.257 -2.00E-01 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------0.6048 0.3952 1.1530 80.757 -5.48E-02 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------0.5450 0.4550 1.0710 81.856 -9.54E-02 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------0.4549 0.5451 0.9791 83.467 -1.05E-01 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------0.3560 0.6440 0.9180 85.366 -2.64E-02 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------0.1221 0.8780 0.7920 89.956 1.62E-01 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------0.0000 1.0000 0.6581 92.514 -1.06E-08 Benzene+NMP 1.0000 0.0000 1.5595 99.538 4.50E-09 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------0.8929 0.1071 1.4504 98.566 4.51E-02 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------0.7810 0.2190 1.3550 97.432 1.08E-01 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------0.6836 0.3164 1.2600 96.330 1.26E-01 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------0.5309 0.4691 1.0980 94.370 8.79E-02 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------0.3817 0.6183 0.9680 93.650 1.03E-01 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------0.2730 0.7270 0.8770 93.232 9.92E-02 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------0.0933 0.9067 0.7410 92.773 8.60E-02 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------0.0000 1.0000 0.6581 92.514 -1.06E-08 Benzene+T EGDME 1.0000 0.0000 1.6860 182.560 1.07E-08 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------0.8156 0.1844 1.6060 170.056 4.52E-01 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------0.7110 0.2890 1.5230 160.072 5.93E-01 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------0.5342 0.4658 1.3620 143.158 7.52E-01 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------0.3753 0.6248 1.2040 128.066 8.03E-01 607 J. App. Sci. Res., 5(6): 605-612, 2009 Table 1: Continue 0.2468 0.7532 1.0575 115.902 7.56E-01 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------0.1540 0.8460 0.9182 105.900 5.51E-01 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------0.0518 0.9482 0.7367 96.000 1.66E-01 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------0.0000 1.0000 0.6581 92.514 -1.06E-08 Benzene+DMF 1.0000 0.0000 0.8759 78.345 -1.76E-09 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------0.9122 0.0878 0.8375 80.240 -2.63E-02 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------0.7292 0.2708 0.7896 83.099 -3.13E-02 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------0.6780 0.3220 0.7770 83.821 -3.46E-02 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------0.5852 0.4148 0.7622 85.000 -1.99E-02 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------0.4349 0.5651 0.7418 86.840 1.11E-02 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------0.2630 0.7370 0.7206 89.060 5.35E-02 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------0.1137 0.8863 0.6941 90.903 5.57E-02 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------0.0000 1.0000 0.6581 92.514 -1.06E-08 Benzene+T ET G 1 0 0.6580 89.988 0 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------0.9459 0.0541 0.8320 94.510 0.0948 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------0.8861 0.1139 1.1400 99.532 0.3332 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------0.8194 0.1806 1.6500 105.062 0.6357 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------0.7446 0.2553 2.2200 111.370 0.6801 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------0.6603 0.3397 3.2000 118.452 0.7824 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------0.5644 0.4355 5.2200 126.470 1.0884 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------0.4545 0.5455 8.2200 135.621 1.1406 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------0.3271 0.6729 13.6300 146.248 1.2005 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------0.1776 0.8224 20.6700 158.977 0.6888 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------0.0000 1 32.2300 174.088 0.0000 Benzene+DEGDME 1.0000 0.0000 1.0020 143.261 5.28E-07 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------0.8493 0.1507 0.9820 135.179 1.29E-01 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------0.7000 0.3000 0.9520 128.320 2.42E-01 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------0.5934 0.4066 0.9150 121.433 2.33E-01 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------0.3851 0.6149 0.8550 110.338 2.71E-01 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------0.2116 0.7884 0.7820 101.055 2.00E-01 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------0.1400 0.8600 0.7390 97.620 1.25E-01 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------0.0651 0.9349 0.6990 94.300 5.93E-02 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------0.0000 1.0000 0.6581 92.514 0.00E+00 608 J. App. Sci. Res., 5(6): 605-612, 2009 Table 2: Mole fractions (x1 , x 2 ), refractive indices (nD) at 30 oC and excess refractive indices (n E E ) of benzene with different solvents. Benzene + T EG X2 nD nE E X1 1.0000 0.0000 1.4508 0.0000 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------0.8866 0.1134 1.4547 -0.0006 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------0.7427 0.2573 1.4593 -0.0017 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------0.6732 0.3268 1.4618 -0.0019 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------0.5795 0.4205 1.4653 -0.0022 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------0.4669 0.5331 1.4700 -0.0019 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------0.3543 0.6457 1.4744 -0.0020 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------0.2000 0.8000 1.4815 -0.0010 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------0.0000 1.0000 1.4904 0.0000 Benzene + DMSO 1.0000 0.0000 1.4745 0.0000 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------0.9185 0.0815 1.4758 -0.0002 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------0.7450 0.2550 1.4777 -0.0016 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------0.6048 0.3952 1.4811 -0.0009 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------0.5450 0.4550 1.4835 0.0004 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------0.4549 0.5451 1.4864 0.0015 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------0.3560 0.6440 1.4890 0.0023 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------0.1221 0.8779 1.4925 0.0013 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------0.0000 1.0000 1.4935 0.0000 Benzene + NMP 1.0000 0.0000 1.4953 0.0000 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------0.8929 0.1071 1.4687 -0.0263 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------0.7810 0.2190 1.4690 -0.0257 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------0.6836 0.3164 1.4707 -0.0237 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------0.5309 0.4691 1.4742 -0.0197 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------0.3817 0.6183 1.4773 -0.0162 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------0.2730 0.7270 1.4799 -0.0133 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------0.0933 0.9067 1.4862 -0.0065 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------0.0000 1.0000 1.4924 0.0000 Benzene+T EGDME 1.0000 0.0000 1.4200 0.0000 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------0.8156 0.1844 1.4237 -0.0097 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------0.7110 0.2890 1.4262 -0.0147 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------0.5342 0.4658 1.4322 -0.0215 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------0.3753 0.6247 1.4404 -0.0248 -----------------------------------------------------------------------------------------------------------------------------------------------------------------------------0.2468 0.7532 1.4557 -0.0188 609 J. App. Sci. Res., 5(6): 605-612, 2009 Table 2: Continue 0.1540 0.8460 1.4673 -0.0140 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------0.0518 0.9482 1.4835 -0.0051 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------0.0000 1.0000 1.4924 0.0000 Benzene+DMF 1.0000 0.0000 1.4279 0.0000 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------0.9122 0.0878 1.4322 -0.0014 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------0.7292 0.2708 1.4405 -0.0049 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------0.6780 0.3220 1.4429 -0.0058 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------0.5852 0.4148 1.4490 -0.0057 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------0.4349 0.5651 1.4612 -0.0031 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------0.2630 0.7370 1.4751 -0.0003 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------0.1137 0.8863 1.4851 0.0000 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------0.0000 1.0000 1.4924 0.0000 Benzene+T ET EG 1.0000 0.0000 1.4555 0.0000 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------0.9459 0.0541 1.4570 -0.0030 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------0.8860 0.1140 1.4599 -0.0052 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------0.8193 0.1807 1.4628 -0.0069 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------0.7446 0.2554 1.4674 -0.0077 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------0.6603 0.3397 1.4717 -0.0080 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------0.5644 0.4356 1.4751 -0.0088 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------0.4545 0.5455 1.4786 -0.0094 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------0.3270 0.6730 1.4828 -0.0076 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------0.1776 0.8224 1.4872 -0.0050 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------0.0000 1.0000 1.4922 0.0000 Benzene+DEGDME 1.0000 0.0000 1.4045 0.0000 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------0.8493 0.1507 1.4215 0.0038 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------0.7000 0.3000 1.4391 0.0082 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------0.5934 0.4066 1.4488 0.0086 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------0.3851 0.6149 1.4663 0.0078 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------0.2116 0.7884 1.4776 0.0038 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------0.1400 0.8600 1.4822 0.0021 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------0.0651 0.9349 1.4866 -0.0001 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------0.0000 1.0000 1.4924 0.0000 610 J. App. Sci. Res., 5(6): 605-612, 2009 Fig. 2: Exces s Referactive Indices (n ED) vs the M ole Fraction X1 of Benzene with the Solvents . Conclus ion: The ÄGE was calculated from t he vis cos ity ç , a ll values are +ve except for DM F and DM SO a re –ve. Pos itive value indicates that the s trength of interaction are s tronger which coming in the order TETEG> TEGDM E > TEG > DEGDM E > NM P > DM F > DM SO all s olvents has a polarity. The n ED als o calculated and s ho w negative deviation and as we s aid before the more negative means more s trength interactio n w hich give the s ame explanation as ÄGE for our s tudied s olvents . The interactions include formatio n o f hydrogen bonds and other comp le x fo rming interactions . Structure contributions aris ing from geometrical fitting of one component into the other becaus e of differences in molar volume and free volume between components , that is the molar volume of pure s olvent is t h e s u m of the actual molecular volumes plus t h e “empty” volume that aris es from hydrogen bonded s tructure. This finding reveals that t h e s trength of intermolecular hydrogen bonding is not only the fac tor in fluencing the ÄGE of liquid mixtures but the s ize a n d s hapes of the components are als o equally important. It is clear that the big ger the s olvent molecule the s tronger t h e s t rength of the interaction, that is explain the rule of the chemical s tructure, in s trength of interaction and +v e value of exces s free energies of s olution. REFERENCES 1. 2. 3. 4. 5. 6. 7. 8. ACKNOWLEDGMENTS The authors wis h to expres s their deep gratitude to M r. M us tafa F . Farag for his kind as s is tance in technical computing. 611 Gracia, B., R. A lde, J.M .l. Lea a n d J .S. M atos , 1996. Formamide-(C1 -C 5 ) A lka n -1-Ols Solvent Sys tems . J. Chem. S o c . Faraday Trans . 92, 3347 and 93, 1115, 1997. M a h a n , Y., C.N. Liew and A .E. M ather, 2002. Vis cos ities and Exces s Properties of A queous Solutions of Ethanolamines at Tempera t u re s Btween 298.15 and 353.15K. J. Solution Chem.. 31: 743. Scheiner, S.. 1997. Hydrogen Bonding: A theoritical Pers pective (Oxford Univers ity Pres s , New York. W o rmald C.J. and C.J. Sowden, 1997. BenzeneEthanol A s s ociation, The Exces s M olar Enthalpy a n d S e c o n d Viria l Cros s -Co e ffic ie n t fo r (Benzene+Ethanol) and (Cyclohexane+Ethanol). J. Chem. Thermodynamic, 29: 1233. Shunqin, L., H. Xin g e n and L. Ruis en, 1999. A p p a r e n t M o l a r V o l u me s o f S o d iu m Chlorobenzoates in N,N-Dimethylformamid e-W ater M ixtures at 298.15K. J. Ch e m. Eng. Data, 44: 353. Kres tov, G.A ., 1991. Themodynamics of Solva t ion, Eills Harwood, England. M arcus , Y., 1977. Introduction to liquid s tate chemis try, W iley-Inters cience, London. Ferreira, P.O., D. Barbos a and D .G. M edina, 1984. "P h a s e Equilibria for the Separation of A romatic and Nonaromatic Compounds Us ing Solvents . P a rt1. Th e S y s t e m n -H e p t a n e - T o lu e n e N .me thylpyrrolidone/M onoethyeneglycol". Fluid Phas e Equilib., 15: 309. J. App. Sci. Res., 5(6): 605-612, 2009 9. 10. 11. 12. 13. 14. 15. Sahar, M . Tawfik, Ebaa A . El-Shamy, and Farid Farag, 2005. Binary M ixt u re s P roperties of N.methy lpyrrolidone and Dimethyls ulphoxide with Benzene, Toluene and Xylene at 20 and 300c. Egypt. J. Petrol., 14(2): 89-101. Fara g , F.M ., Sahar M . Tawfik and Ebaa A . ElS h a my , 2003. S t u d y o f S o m e E xc e s s T hermodynamic Functions for Binary M ixtures o f Triethyleneglycol-Dimethylether (TEGDM E) and Dimethylformamide(DM F) with Some A romatic Hydrocarbons . Egypt. J. A ppl. Sci, 18(12). F arag, F.M . and Sahar M . Tawfik, 2007. Bina ry M ixtures Properties of Tetraethyleneglycol with Benzene and Tolue n e at 20 and 300c. 15th LA W PSP Sympos ium, India, 01.1-01.7. Erde y – Grus , T., 1974. Trans port Phenomena in A queous Solutions , John W iley, New York, 93. Corradini, F., A . M archetti, M . Tagliazuechi, L. Tas s i and G. Tos i, 1994. Thermodynamic A nalys is of Vis cos it y Data of Ethane-1,2 Diol +1,4- Dioxan Binary M ixtures . A us t. J. Chem., 47: 1117-1126. Glas s tone, S., K. Jr Laide and H. Eyrin g , 1941. M cGraw – Hill, New York, 514. A l- A zzawi, S.F. and A .M . A wwad, 1990. Exces s M olar Volumes , Exces s Logarithmic Vis cos ities and Exces s A ctiviation Energie s o f Vis cous Flow for 2-Ethoxyethanol-ã-Butyrolactone and Sulfolane at 303.15K. J. Chem. Eng. Data, 35: 411 – 414. 16. El – Dos s oki, S.I. a n d E.A . Goma, 2005. Dens ities and Refractive Indices of P u re A lcohols as a Function of Tempera t u re. India Chem. Soc., 82: 219. 17. Re e d, T.M . and T.E. Taylor, 1959. Vis cos ities of Liquid M ixtures . J. Phys . Chem., 63: 58. 18. Nath, J. and S.K. M is hra, 1998. Relative Permittivities Indices of Binary M ixtu re s of Cy c lo h e xa n o n e w it h Dichloromethane, 1,2Dichloroethane, Trichloroethane and Cyclohexane at T=303.15K. Fluid Phas e Equilib., 154: 89. 19. M as cato, E., L. M os terio, M .M . Pine iro, Garcia, 2001. Thermodynamics Properties of M ixing for ( 1 -A lka n o l+ n -A lka n e + A c y c lic A lka n e ) a t T = 2 9 8 . 1 5 k . 1 . ( n H e x a n e + C y c l o h e xa n e + 1.Bu t a n o l. J . Ch e m . Thermodynamics , 33: 269. 20. Farag, F.M . and M . Saha r, Tawfik, 2008. Study of t h e A lc o h o l S o lu t ion Us ing t h e Exc e s s Thermodynamic F u n c t io n . 16 t h In t e rn a t io n al collcquium Tribolog y “Lubricants , M aterials and lubrication Engineering”, Stuttgart, Germany. 612