Research and Reviews: Journal of Pure and Applied Physics

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1 Research and Reviews: Journal of Pure and pplied Physics Studyof Ultrasonic Velocity, Densityand Viscosityin the inary Mixturesof enzyl enzoatewith 1-Octanol andisophorone J Glory 1, PS Naidu 2 *, N Jayamadhuri 3, and K Ravindra Prasad 1 1Department of Physics, VSU PG Centre, Kavali , ndhra Pradesh, India. 2Department of Physics, J Degree& PG College, Kavali , ndhra Pradesh, India. 3NKR Institute of Science and Technology, Vidyanagar , ndhra Pradesh, India. Research rticle Received: 15/03/2013 Revised: 04/04/2013 ccepted: 09/04/2013 STRCT *For Correspondence: Department of Physics, J Degree & PG College, Kavali , ndhra Pradesh, India. Mobile: Ultrasonic velocity, density and viscosity have been measured using the standard techinques in the binary mixtures of benzyl benzoate (1 and 1-octanol (2 and isophorone (2. In the light of the excess parameters like excess adiabatic compressibility, excess internal pressure, excess enthalpy, excess activation energy etc. computed from the measured data, intermolecular interactions are estimated as strong interactions in both the mixtures. It is also observed that all the theories except FLT and VNDEL have a sharp edge in predicting the velocities theoretically. Keywords: Molecular interactions, binary mixture, benzyl benzoate, isophorone, adiabatic compressibility. INTRODUCTION Through several binary mixtures of benzyl benzoate [1,2,3,4,5,6,7] have been studied ultrasonically, still the investigations are going on. In view of the importance medicinally, the behaviour of benzyl benzoate in cyclic unsaturated ketone, isophorone and a high alkanol, 1-octanol, has been ultrasonically studied in the present investigation. enzyl benzoate is an insect repellant and used as a solubilizing agent, in oily injections and medicine for scabbies. 1-octanol, a fattyalcolhol, is used in the manufacture of esters used in perfumes and flavouring, in pharmaceutical industry and also in controlling essential tremors and other types of involuntary neurological tremors. Isophorone, which is an α β unsaturated cyclic ketone, is used as solvent in some printing inks, paintings, lacquers, adhesives and some pesticides. It is also an ingradient in wood preservations and floor sealants. Ultrasonic velocity, density and viscosity have been measured experimentally at three temperatures in the two binary mixtures of benzoate. From knowledge of excess thermodynamic / acoustic parameters computed, the molecular interactions have been investigated / estimated. lso a theoretical evaluation of velocities has been attempted successfully. lmost all the theories except FLT and VNDEL agree well with the experiment in both the mixtures. nd mostly strong interactions are suggested in both the binary mixtures at all temperatures. EXPERIMENTL Ultrasonical velocity has been measured using a single crystal variable path interferometer working at 2 MHz with an accuracy of %. Density and viscosity have been measured employing a double stem capillary type pyknometer and Ostwald viscometer with accuracies of 2 parts in 10 5 and + 0.1% respectively. ll the chemicals used here are of analar / fine grade. Weights are taken using a single pan electronic balance with an accuracy of mg. Temperature is maintained to within +0.01K employing an electronically controlled Thermostatic water bath. For standardizing the measurements, triply distilled water has been chosen as a reference liquid. RRJPP Volume 1 Issue 2 pril June,

2 Theoretical spects: Employing the standard theories -- FLT due to JCOSON, CFT due to SCHFFS, NOMOTO, VNDEL, JUNJIEand JOUYN CREE, ultrasonic velocity can be evaluated theoretically. K U = (1 L ρ FLT 1/2 f mix U = CFT US V mix M T mix (2 U NOMOTO 3 3 R (XR XR (3 V (X V X V U 1 X X X M X M M U M U VNDEL 1/2 2 2 (4 U JUNJIE (5 1/2 X M X XM ρ M XM ρ XM 2 V ρ X M V ρ 2 Velocity(U in the mixture due to JOUYN CREE is given by lnu J = X lnu + X lnu + (X X /T [ (X -X + 2 (X -X 2 ] (6 The thermodynamic/acoustic and other related parameters can be computed from the following relations. diabatic Compressibility 1 = 2 U ρ (7 exp exp Internal pressure = brt [K/U] 3/2 2/3 / M 7/6 (8 Free volume V f = [M eff U / K] 3/2 (9 Enthalpy H = V M (10 RRJPP Volume 1 Issue 2 pril June,

3 ctivation Energy G = RT [ lnv M ] (11 ll the excess parameters are calculated using the following relation E = exp ideal = exp (X 1 1 +X 2 2 (12 ll the quantities used in the above equations have their usual meaning as explained elsewhere [8]. RESULTS ND DISCUSSION Ultrasonic velocity, density and viscosity have been measured experimentally for the two binary systems 1 benzyl benzoate + 1- octanol and 2 benzyl benzoate + isophorone at three temperatures 30,40 and 50 0 C. The results and discussion have been made systematically and separately for the two systems and a comparison is made at the end. ll the pure liquids are highly polar (dipole moment =3.9D, 2.0D and 3.96D for enzyl benzoate, 1-octanol and isophorone respectively. enzyl benzoate + 1 octanol Ultrasonic velocity, density and viscosity measured experimentally at three temperatures 30, 40 and 50 o C have been presented in Table 1. Variation of experimental velocity with concentration has been shown in Fig.1 along with the theoretically evaluated velocities. Velocity increases from octanol to benzyl benzoate at all the three temperatures. From the maximum percentage deviations i.e., -5.26, 2.25, 1.56, , 1.11 and 0.39 in FLT, CFT, NOMOTO, VNDEL, JUNJIE and JOUYN CREE respectively, it may be inferred that JOUYN CREE agrees very well while FLT and VNDEL show large deviations. From the measured values of viscosity, density and velocity, thermodynamic and other related parameters like adiabatic compressibility (β, internal pressure (π, enthalpy (H, activation energy (G, free length (Lf etc., are computed and presented in Table 2. It may be seen that β, π and Lf decrease regularly while H also decreases but not regularly. Molar volume (Vm and G increase from octanol to benzoate at all temperatures. ut to assess the nature of chemical reactions / intermolecular interactions, excess parameters would be of much use and hence the computed excess parameters are shown in Figs Lf E and β E are both negative upto high concentration ( ~ 0.8m and thereafter positive at all temperatures. П E and H E are also negative throughout with a minimum nearly at equimolar concentrations (~0.5m - less negative after 0.5m. η E and G E are also negative throughout. It may be abserved that almost all excess parameters are negative and behave similarly with temperature. From the negative excess parameters, it may be indicated that there exists strong interamolecular interactions in the binary mixture and small variation in the parameters at high temperatures may be due to the small relative association between the molecules of 1-octanol also. From η E and G E, negative throughout the composition range at all temperatures, exothermic reactions appear to be predominant. enzyl benzoate + isophorone Isophorone is a cyclic unsaturated ketone which readily reacts with benzoate, an ester. s discussed from Fig.8, velocity increases from isophorone to benzoate monotonously and most linearly at all temperatures. Velocity, density and viscosity in this system are shown in Table 3. Maximum percentage deviations observed in various theories are 4.38, 0.98, -0.17, -4.26, and in FLT, CFT, NOMOTO, VNDEL, JUNJIE and JOUYN CREE respectively at 30 o C. Except FLT and VNDEL, all the other theories agree reasonably with the experiment (<1% deviation. From the measured data experimentally, thermodynamic / other related parameters are computed and shownin Table 4. β and Lf show decreasing trend from isophorone to benzoate while the others π, Vm, H and G increase. The excess parameters computed for understanding the molecular interactions effectively have been shown in Figs It can be seen that β E, Lf E, π E and H E are all negative throughout at all temperatures while at 50 o C G E and η E are negative and positive at 40 o C throughout the concentration range. t 30 0 C,both negative and positive are noticed. In this system also, it is clearly indicated that strong intermolecular interactions of the type besides dipole dipole interactions are predominant at all temperatures. t 30 o C, both endothermic and exothermic type of chemical reactions are suggested which transform into endothermic at 40 o C. t this point of journey, a comparison of our results with those of other researchers in similar systems is desirable and hence is presented hereunder. RRJPP Volume 1 Issue 2 pril June,

4 velocity(ms -1 velocity(ms -1 velocity(ms (U EXP (U CFT (U FLT (U VNDEL (U JUNJIE (U NOMOTO (U J mole fractionof enzyl enzoate Fig. 1(i. Variation of ultrasonic velocity with the mole fraction of benzyl benzoate at 30 0 C in the binary mixture: benzyl benzoate + 1-octanol (U EXP (U CFT (U FLT (U VNDEL (U JUNJIE (U NOMOTO (U J 1260 mole fractionof enzyl enzoate Fig. 1(ii. Variation of ultrasonic velocity with the mole fraction of benzyl benzoate at 40 0 C in the binary mixture: benzyl benzoate + 1-octanol (U EXP (U CFT (U FLT (U VNDEL (U JUNJIE (U NOMOTO (U J mole fractionof 0.4 enzyl enzoate Fig.1(iii. Variation of ultrasonic velocity with the mole fraction of benzyl benzoate at 50 0 C in the binary mixture: benzyl benzoate + 1-octanol RRJPP Volume 1 Issue 2 pril June,

5 excess pressure(atms excess free length( 0 excess adiabatic compressibility(10-11 N -1 m mole fraction 0.4 of enzyl benzoate (30 0 C (40 0 C (50 0 C Fig. 2. Variation of excess adiabatic compressibility with the mole fraction of benzyl benzoate at three different temperatures in the binary mixture: enzyl benzoate + 1-octanol mole fraction of enzyl benzoate (30 0 C (40 0 C (50 0 C Fig. 3. Variation of excess free length with the mole fraction of benzyl benzoate at three different temperatures in the binary mixture: enzyl benzoate + 1-octanol 0 mole fraction of benzyl benzoate (30 0 C (40 0 C (50 0 C Fig. 4. Variation of excess internal pressure with the mole fraction of benzyl benzoate at three different temperatures in the binary mixture: enzyl benzoate + 1-octanol RRJPP Volume 1 Issue 2 pril June,

6 excess viscosity(millipa.s excess activation energy(rt units excess enthalpy(kjmole mole fraction of enzyl benzoate (30 0 C (40 0 C (50 0 C Fig. 5. Variation of excess enthalpy with the mole fraction of benzyl benzoate at three different temperatures in the binary mixture: benzyl benzoate + 1-octanol mole fraction of enzyl benzoate (30 0 C (40 0 C (50 0 C Fig. 6.Variation of excess activation energy with the mole fraction of benzyl benzoate at three different temperatures in the binary mixture: benzyl benzoate + 1-octanol 0.0 mole fraction of enzyl benzoate (30 0 C (40 0 C (50 0 C Fig. 7. Variation of excess viscosity with the mole fraction of benzyl benzoate at three different tempeartures in the binary mixture: benzyl benzoate + 1-octanol RRJPP Volume 1 Issue 2 pril June,

7 velocity(ms -1 velocity(ms -1 velocity(ms (U EXP (U CFT (U FLT (U VNDEL (U JUNJIE (U NOMOTO (U J mole fractionof 0.4 enzyl enzoate Fig.8(i. Variation of velocity with the mole fraction of benzyl benzoate at 30 0 C in the binary mixture: benzyl benzoate + isophorone (U EXP (U CFT (U FLT (U VNDEL (U JUNJIE (U NOMOTO (U J mole fraction of enzyl benzoate Fig. 8(ii. Variation of velocity with the mole fraction of benzyle benzoate at 40 0 C in the binary mixture; benzyl benzoate + isophorone (U EXP (U CFT (U FLT (U VNDEL (U JUNJIE (U NOMOTO (U J mole fractionof enzyl benzoate Fig. 8(iii. Variation of velocity with the mole fraction of benzyl benzoate at 50 0 C in the binary mixture: benzyl benzoate + isophorone RRJPP Volume 1 Issue 2 pril June,

8 excess internal pressure(atms excess free length( 0 adiabatic compressibility(10-11 N -1 m 2 0 mole fraction of enzyl benzoate (30 0 C (40 0 C (50 0 C -6 Fig. 9. Variation of excess adiabatic compressibility with the mole fraction of benzyl benzoate at three different temperatures in the binary mixture: enzyl benzoate + isophorone mole fraction of enzyl benzoate (30 0 C (40 0 C (50 0 C Fig. 10. Variation excess free length with the mole fraction of benzyl benzoate at three different temperatures in the binary mixture: benzyl benzoate + isophorone mole fraction of benzyl benzoate (30 0 C (40 0 C (50 0 C Fig.11. Variation of excess internal pressure with the mole fraction of benzyl benzoate at three different temperatures in the binary mixture: enzyl benzoate + isophorone RRJPP Volume 1 Issue 2 pril June,

9 excess viscosity(millipa.s excess activation energy(rt units excess enthalphy(kjmole mole fraction of enzyl benzoate (30 0 C (40 0 C (50 0 C Fig. 12. Variation of excess enthalpy with the mole fraction of benzyl benzoate at three different temperatures in the binary mixture : enzyl benzoate + isophorone (30 0 C (40 0 C (50 0 C mole fraction of enzyl benzoate Fig. 13.Variation of excess activation energy with the mole fraction of benzyl benzoate at three different temperatures in the binary mixture: benzyl benzoate + isophorone (30 0 C (40 0 C (50 0 C 0.0 mole fraction of enzyl benzoate Fig. 14. Variation of excess viscosity with the mole fraction of benzyl benzoate at three different tempeartures in the binary mixture: benzyl benzoate and isophorone RRJPP Volume 1 Issue 2 pril June,

10 Table 1: Experimental data of Velocity (U, density (ρ and viscosity (η as a function mole fraction of benzyl benzoate at three different temperatures in the binary mixture: benzyl benzoate + 1-octanol. Mole fraction of enzyl enzoate Velocity (ms -1 Density (kgm -3 Viscosity (millipa.s 30 0 C C C RRJPP Volume 1 Issue 2 pril June,

11 Table 2. Various thermodynamic parameters - enthalpy, internal pressure, free length, free volume, molar volume, adiabatic compressibility, activation energy as a function of mole fraction benzyl benzoate at three temperatures in the binary mixture : benzyl benzoate + 1-octanol. Mole fraction of enzyl enzoate diabatic compressibility (10-10 N -1 m 2 Internal pressure (atms Molar volume (10-3 L.mole -1 Free length ( 0 Enthalpy (kj.mole -1 ctivation energy (RT units 30 0 C C C RRJPP Volume 1 Issue 2 pril June,

12 Table 3: Experimental data of Velocity (U, density (ρ and viscosity (η as a function of mole fraction of benzyl benzoate at three different temperatures in the binary mixture : benzyl benzoate + isophorone. Mole fraction of enzyl enzoate Velocity (ms -1 Density (kgm -3 Viscosity (millipa.s 30 0 C C C RRJPP Volume 1 Issue 2 pril June,

13 Table 4:Various thermodynamic parameters - enthalpy, internal pressure, free length, free volume, molar volume, adiabatic compressibility, activation energy as a function of mole fraction benzyl benzoate at three temperatures in the binary mixture : benzyl benzoate + isophorone. Mole fraction of enzyl enzoate diabatic compressibility (10-10 N -1 m 2 Internal pressure (atms Molar volume (10-3 L.mole -1 Free length ( 0 Enthalpy (kj.mole -1 ctivation energy (RT units 30 0 C C C In the binary mixtures of benzyl benzoate with alcohols (methanol, ethanol, 1-propoanol, 1-butanol, strong interactions besides dipole dipole interactions are estimated and the strength of the interaction decreased with the chain length. In the ketone systems (MEK & MK and acetophenone system also, mostly strong intermolecular interactions are suggested through weak interactions at some concentrations are not totally ruled out. The nature of chemical reaction is endothermic in the systems with alcohols and the two ketones (MEK & MK at all temperatures. In acetophenone system, endothermic type of reactions is also predominant at some concentrations and temperature. Other studies in benzyl benzoate and methyl benzoate 9 and other systems [10, 11] also reveal similar type of interactions from the variation of excess thermodynamic parameters. RRJPP Volume 1 Issue 2 pril June,

14 Referring to the above literature on benzyl benzoate systems, our results and discussion are in conformity. In the mixture with the unsaturated cyclic ketone, exothermic at 30 o C and endothermic at high temperatures and totally exothermic at all temperatures in the higher alcohol system are noticed. In both the systems, strong interactions besides dipole dipole interactions are suggested. The highly polar nature of the constituents - the benzoate and isophorone may be the reason for (nearly equal stronger interactions in the binary mixture compared to the other mixture. CKNOWLEDGEMENTS The authors thank SVU and VSU authorities for providing the necessary facilities for carrying out this work. One of the authors (JG acknowledges the sanction of RGNF (Senior by the UGC. REFERENCES 1. Siva Sankar J, Geeta Lakshmi M, Naidu P S and Ravindra Prasad K. Excess parameters of the binary mixtures of benzyl benzoate in dichloromethane and isobutanol. J Pure pplultrason. 2007;29: Geeta Lakshmi M, Naidu P S and Ravindra Prasad K. Molecular interactions in binary mixtures of benzyl benzoate with alcohols.j Pure ppl Ultrason. 2008;30: Ramesh P, Geeta Lakshmi M, JayaMadhuri N, Naidu P S and Ravindra Prasad K. Molecular interactions in the inary Mixtures of enzyl benzoate in enzene nd substituted enzenes - an Ultrasonic Study.Invertis Journal of Science&Technology.2011;4: Mallikarjuna P, Jaya Madhuri N and Ravindra Prasad K. Molecular Interactions in the binary mixture of benzyl benzoate n Ultrasonic Study. J Pure pplultrason. 2010;32: NageswaraRao J, Jayamadhuri N, Glory J, Naidu P S and Ravindra Prasad K. Excess thermodynamic and other allied parameters in the binary mixtures of and azocompunds with benzyl benzoate as common component.physical Chemistry an Indian Journal, 2013;In Press. 6. Jaya Madhuri N, Naidu P S, Glory J and Ravindra Prasad K. Ultrasonic investigations Molecular Interaction in inary Mixtures of enzyl enzoate with acetonitrile and enzonitrile.e-journal of Chemistry.2011;89(1: Jaya Madhuri N, Glory J,Naidu P S and Ravindra Prasad K. Ultrasonic study andallied properties of the binary mixtures of acetophenone and NN dimethyl formamide with benzyl enzoate as common component.j Pure pplultrason.2011;33: Jayamadhuri N, Glory J, Naidu P S and Ravindra Prasad K. Study of molecular interactions in the binary mixtures of benzyl benzoate with carbondisibhide and diethyl erther, Proceedings of Eighteenth National Symposium on Ultrasonics. Proceedings of Eighteenth National Symposium on Ultrasonics, NSU XVIII VIT University, Vellore. 2009;December21-23: Pandhari Nath, Nikam S and Sanjeevan Kharat J. Density and viscosity studies of binary mixtures of N, N-Dimethyl formamide with toluene and Methyl enzoate at (298.15, , and K. JChemEng Data.2005;50: Shahla Parveen, Divya Shukla, Shashi Singh, Singh K P, Manisha Gupta, ShuklaJ P. Ultrasonic velocity, density, viscosity and their excess parameters of the binary mixtures of tetrahydrofuran with methanol and o-cresol at varying temperatures.pplied coustics.2009, 70: Elisa Langa, na Mainar M, Juan Pardo I and Jose Urieta S. Excess enthalpy, and speed of sound Deviation for the mixtures β - pinene + Ethanol and β - pinene + 1-propanol at (283.15, and K. J ChemEng Data.2005;50: RRJPP Volume 1 Issue 2 pril June,