Available online at http://www.urpjournals.com International Journal of Research in Pure and Applied Physics Universal Research Publications. All rights reserved ISSN 78-34 Original Article ACOUSTICAL STUDIES OF BINARY LIQUID ITURES OF P-CHLOROTOLUENE IN CHLOROBENZENE AT DIFFERENT TEPERATURES G. Pavan Kumar, Ch. Praveen Babu, 3 K. Samatha, 4 A. N. Jyothsna and 5 K. Showrilu, & 3 Ultrasonic Laboratory, Department of Physics, Andhra University, Visakhapatnam-530003. 4&5 Physics dept. St. Theresa College, Eluru. Andhra Pradesh, India. E-mail: pavan.phy@gmail.com Received 6 February 04; accepted 06 arch 04 Abstract Ultrasonic velocity, density and viscosity have been measured for P -Chlorotoluene with chlorobenzene at different temperatures 303.5K, 308.5K, 33.5K and 38.5K at a fixed frequency of Hz over the whole concentration range of Hz. Using the experimental data thermodynamic parameters such as adiabatic compressibility (β ad ), inter molecular free Length (L f ), acoustical impedance (Z), molar volume (V m ), Rao s constant (R), Wada s constant (W), Viscosity (η), internal pressure (π) and Free volume (V f ) have been calculated. The nature of variation in these parameters with concentration and temperature has been used to understand the type and the strength of molecular interactions present in the system investigated. 03 Universal Research Publications. All rights reserved Keywords: Ultrasonic velocity, thermodynamic parameters, P-Chlorotoluene, Chlorobenzene and molecular interactions.. Introduction: The present work is a research programme on thermodynamic, thermo-acoustic and transport behaviour of binary liquid mixtures of industrially important components [-3]. In recent years, ultrasonic technique has become a powerful tool in providing information regarding the molecular behaviour of liquids and liquid mixtures owing to its ability of characterizing physicochemical behaviour of the medium [4-5]. When two or more liquids are mixed, there occur some changes in physical and thermodynamic properties because of change in volume, energy and molecular interactions. Ultrasonic velocity measurements in liquids provides an information about inter and intra molecular interactions. Thermodynamic parameters derived from the exp erimental data are extremely used to study the molecular interactions in liquid systems, aqueous solutions and liquid mixtures. In recent years, there has been considerable progress in the determination of thermodynamic, acoustic and transport properties of liquid systems from density and velocity measurements [6-7]. The measurements of density, ultrasonic velocity, viscosity and the thermodynamic properties derived from these are excellent tools to detect solute-solute and solute-solvent interactions. Even though the ultrasonic velocity data do not provide enough information about the native and the relative strength of various types of intermolecular interionic interactions between the components, their derived parameters such as acoustical impedance, adiabatic compressibility, intermolecular free length, molar volume, Rao s Constant, Wada s Constant, internal pressure and free volume are very useful in the study of molecular interactions. In view of the above we have carried out systematic experimental investigations of the ultrasonic velocity, density and viscosity measurements of aromatic hydrocarbons at different concentrations at different temperatures. Here we have reported experimental and thermodynamic parameters of P-Chlorotoluene with chlorobenzene system.. Experimental Details: All the chemicals used were of Analytical Reagent (AR) grade with minimum array of 99.9%. The ultrasonic velocity (U) have been measured using an ultrasonic interferometer (ittal Enterprises, odel F-8) working at Hz frequency with an accuracy of ± 0. ms -. An
electronically digital operated constant temperature water bath has been used to circulate water through the double walled measuring cell made up of steel containing the experimental solution at the desire temperature. The density of pure liquids and liquid mixtures was determined using density gravity bottle with a c c u r a c y of ±0.Kgm -3. An Ostwald s viscometer was used for the viscosity measurements with an accuracy of ±0.000 NSm -. The temperature around the viscometer and density gravity bottle was maintained within ±0.K in an electronically operated constant temperature water bath. All the precautions were taken to minimize the possible experimental errors. From the measured values of density (ρ) and ultrasonic velocity (U), Viscosity (η). The Adiabatic Compressibility (β ad ), Inter olecular Free Length (L f ), Acoustical Impedance (Z), olar Volume (V m ), Rao s Constant (R), Wada s constant (W), internal pressure (π) and free volume(v f ) were calculated by using the following standard relations.. Adiabatic compressibility (β ad ) ad U. Intermolecular free length (L f ) Lf K ad. Where k is temperature dependent constant called as Jacobson constant. The value of k at the working temperatures of the experiment were calculated (KS units) and they are given below Temperature ( o K) 303.5 308.5 33.5 38.5 Value of K.075 x 0 6.095 x 0 6.5 x 0 6.35 x 0 6 3. Specific acoustic impedance (Z) Z= ρ U.. 3 4. olar volume of the liquid mixture (V m ) m....4 mix V Where 5. olar Sound Velocity or Rao's Constant (R) can be calculated by the relation R= V m U /3.....5 6. olar compressibility or Wada's constant (W) can be calculated by the relation W... 6 7 ad 7. Internal pressure (π) 3 k i brt U 76... 7 here b is packing factor ( b= ), K is a constant, which is independent of temperature and its value is 4.8 0 9 for all liquids, R is universal gas constant and T is absolute temperature. 8. Free volume V f U k 3.8 3. Results and Discussion: The experimentally measured values of Density (ρ), Ultrasonic velocity (U), Viscosity (η) and thermodynamic parameters adiabatic compressibility (β ad ), Intermolecular free length (L f ), Acoustic impedance (Z), olar volume (V m ), Rao s Constant (R), Wada s constant (W), Viscosity (η), internal pressure (π) and free volume(v f ) of P-Chlorotoluene with Chlorobenzene binary liquid system at different temperatures at a frequency of Hz over the whole concentration of P-chlorotoluene are presented in Table-. Table: : Ultrasonic Velocity (U), Density (ρ), Adiabatic Compressibility (β ad ), Inter olecular Free Length (L f ), Acoustical Impedance (Z), olar Volume (V m ), Rao s Constant (R), Wada s constant (W), Viscosity (η), Internal pressure (π) and free volume (V f ) for olefraction of P-Chlorotoluene with Chlorobenzene at different temperatures 303.5K and 308.5K. ole Fraction 0.468 0.468 U ms - 47.80 53.5 56.46 6.34 66.55 7.59 74.93 34.60 37.5 39.94 4.59 45.09 47.53 50.00 ρ Kgm -3 094.3 089.9 085.6 080.3 073.9 066. 058.9 093.4 087.49 08.3 074.67 066.74 057.87 048.7 β ad *0-0.N -.m L f *0-0 m 5.869 5.8387 5.8348 5.879 5.8044 5.8000 5.8099 6.0459 6.039 6.038 6.070 6.04 6.064 6.07 0.506 0.50 0.507 0.503 0.5009 0.5005 0.500 0.55 0.548 0.545 0.545 0.543 0.540 0.536 Z x 0 6 Kg. m s -.3654.3630.3605.3579.3553.357.3500.3440.3405.3370.3334.397.360.3 303.5K 308.5K V m 0-5 m 3 /mol 0.86 05.30 07.87 0.57 3.40 6.39 9.53 03.05 05.59 08.6.46 4.0 7.74 0.4 R 0-7 (m/s) /3 5.399 5.687 5.4036 5.5454 5.6943 5.85 6.064 5.6 5.588 5.398 5.5448 5.6993 5.86 6.034 W 0-7 (Kg - ms ) 0.7988 0.880 0.838 0.8593 0.886 0.9050 0.996 0.7969 0.867 0.8374 0.859 0.88 0.9064 0.930 ŋ 0-3 π i 0-5 V f 0-7 N.S.m - N.m - m 3 mol - 0.755 0.7466 0.7777 0.8088 0.8399 0.870 0.90 0.6766 0.7087 0.7408 0.779 0.8050 0.837 0.869 339.0 337.3 335.03 33.7 39.06 35.4 3.35 337.05 335.73 333.85 33.43 38.49 35.06 3.6 3.049 3.0095.969.8558.795.7438.70 3.308 3.88 3.0847.9956.993.8546.8003
Temperatures at 33.5K and 38.5K. ole Fraction U ms - ρ Kgm -3 β ad *0-0.N -.m L f *0-0 m Z x 0 6 Kg. m s - 33.5K V m 0-5 m 3 /mol R 0-7 (m/s) /3 W 0-7 (Kg - ms ) ŋ 0-3 N.S.m - π i 0-5 N.m - V f 0-7 m 3 mol - 0.468. 5.98 0.85 5.75 30.59 35.45 40.4 09.5 086.6 079.5 07.3 063.93 054.57 044.8 6.50 6.48 6.446 6.46 6.39 6.37 6.356 0.588 0.586 0.585 0.583 0.58 0.58 0.580.306.364.3.3078.3034.989.944 03. 05.8 08.57.46 4.5 7.74.5 5.068 5.46 5.3855 5.5360 5.6947 5.863 6.0396 0.7944 0.845 0.8357 0.858 0.886 0.9064 0.93 0.639 0.6664 0.7009 0.7354 0.7699 0.8044 0.8389 333.3 333.03 33.99 330.34 38.07 35. 3.80 3.5785 3.440 3.730 3.5 3.0489.9609.8865 0.468 87.4 9.84 98.38 03.96 09.5 5. 0.8 088.4 08.0 075. 067.86 059.37 050.0 040. 6.565 6.508 6.4897 6.4774 6.4656 6.4545 6.444 0.5450 0.5444 0.5438 0.5433 0.548 0.544 0.549 38.5K.93.889.854.88.78.743.704 03.4 06.07 08.86.8 4.9 8.0.68 5.083 5.8 5.3678 5.57 5.684 5.8558 6.0376 0.79 0.87 0.8334 0.856 0.880 0.9056 0.935 0.5903 0.658 0.663 0.6968 0.733 0.7678 0.8033 330.3 330.45 39.99 38.8 36.93 34.4 3.7 3.8476 3.6469 3.4765 3.335 3.08 3.036 3.054 Density decreases with increasing the concentration of P-Chlorotoluene and also it decreases w i t h increasing the temperature. I t suggests t h a t a solute-solvent interaction exist between P-Chlorotoluene a n d Chlorobenzene system. In other words the decrease in density may be interpreted to the structure maker of the solvent due to H- bonding. The ultrasonic velocity increases with increase in the concentration of P -Chlorotoluene and also decreases with increase in temperature suggesting thereby strong association between solute and solvent molecules [8-9]. From the Table-, the adiabatic compressibility and free length decreases with increasing mole fraction of the P-Chlorotoluene and increases with increasing temperature. Which suggest that making and breaking of H- bonding. The intermolecular free length depends upon the intermolecular attractive and repulsive forces. Eyring and Kincaid [0] have proposed that L f is a predominating factor in determining the variation of ultrasonic velocity of solution. Hence it can be concluded that there is significant interaction between solute and solvent molecules due to which the structural arrangement is also affected. From the above parameters it is clear that there is a strong association between P-Chlorotoluene and Chlorobenzene system. The acoustic impedance (Z) (which is the product of 3
ultrasonic velocity and density of the solution) decreases with increase in concentration of P-Chlorotoluene. It represents that there is strong interaction between the P-Chlorotoluene and Chlorobenzene system [3]. In this system, viscosity increases with increasing molefraction of P-Chlorotoluene and decreases with increasing temperature. Viscosity increases with concentration of P-chlorotoluene confirms that increase of cohesive forces because of strong interaction []. The internal pressure decreases with increasing mole fraction of P-Chlorotoluene. This gives the information regarding the nature and strength of forces existing between the molecules. The increase in free volume indicates that the strength of interaction of molecules in this system. The free volume increases with increase molefraction of P-Chlorotoluene. The free volume is the space available for the molecules to move in an imaginary unit cell [4-5]. It clearly indicates the existence of intermolecular interaction, due to which the structural arrangement is considerably affected. The Rao s constant and Wada s constant values are increases with increase concentration of P-Chlorotoluene and decreases with the increasing temperatures and support the strong interactions. 4. Conclusion: The ultrasonic velocity, density and other related parameters were calculated. The existence of type of molecular interactions in solute-solvent is favored in the system, confirmed from the U, ρ, β ad, L f, Z, V m, R, W, η, π and V f data. Strong dispersive type intermolecular interactions are confirmed in the systems investigated. All the experimental determinations of acoustic parameters are strongly correlated between P-Chlorotoluene with Chlorobenzene. ACKNOELDGEENT One of author s G. Pavan kumar sincerely thank the University Grants Commission, India, for funding the current research work under UGC Scholarship Assistance Program (SAP) in the Department of Physics, Andhra University, Visakhapatnam. References:. Bala Karuna Kumar D., Rayapa Reddy K., Srinivasa Rao G., Rama Rao G.V. and Rambabu. C., J. Chem. Pharm. Res., 3(5) (0) 74-80.. Ramarao G.V., Sarma A.V. and Rambabu C., Indian J. Pure Appl. Phys., 4 (004) 80-86. 3. Ramarao G.V., Sarma A.V., Ramachandran D. and Rambabu C., Indian J. Pure Appl. Phys., 43 (005) 60-608. 4. Ramarao G.V., Sarma A.V., Sandhyasri P.B. Rambabu C., Indian J. Pure Appl. Phys., 45 (007) 35-4. 5. Sreekanth K., Kumar D.S., Kondaiah. and Krishnarao D.,J.Chem.Pharm. Res., 3(4) (0) 9-4. 6. Venis R. and Rajkumar R., J. Chem. Pharm. Res., 3() (0) 878-885. 7. Shilpa irikar, Pravina Pawar P., and Govind Bichile K., J. Chem. Pharm. Res., 3(5) (0) 306-30. 8. Tabhane V.A., Chimankar O.P., anja S. and Naminarayanan T.K.,PureAppl Ultraso., (999) 67. 9. Thirumaran S. and Kannapan A.N., Global J of ole. sci., 4() (009) 60. 0. Eyring B. and Kincadid J.F., J.Chem.Phys, 938, 6,60.. Agrawal P.S., Wagh.S. and Paliwal L.J., Archives of Applied Science Research, 3() (0) 9.. Agrawal P.B., ohd Indrees ohd Siddique. and Narwade.L., Ind. J. Chem, 4A(5) (003) 050. 3. Bhatt Harikrishnan Semwal S.C. and Vijendra 4
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