摘要:
Applicability of thermoacoustical parameters for the computation of available volume in liquid systems J. D. Pandey, Ranjan Dey and Bishan Datt Bhatt aT Department of Chemistry, University of Allahabad, Allahabad -211002 U.P., India. E-mail: bdbhatta@hotmail.com Received 22nd October 2001, Accepted 15th January 2002 Published on the Web 30th January 2002 Available volumes in pure liquids and binary liquid mixture at varying temperature have been computed using thermoacoustical parameters and the values thus obtained are compared with the values obtained from a thermodynamic relation of the available volume. Fairly good agreement between the values from the two methods proves the applicability of thermoacoustical parameters for the computation of the available volume in pure liquids and liquid mixtures.V/1026 m3 mol21 a/1023 K21 V� 1.274 1.285 1.296 1.308 1.320 1.331 1.339 1.246 1.257 1.268 1.278 1.289 1.299 1.305 1.318 1.346 1.376 1.309 1.336 1.363 69.64 70.57 71.44 72.51 73.52 72.69 75.04 59.40 60.10 60.82 61.56 62.32 63.10 63.49 128.44 131.98 135.50 144.59 148.44 152.28 1.33 1.34 1.36 1.38 1.40 1.42 1.44 1.17 1.18 1.20 1.21 1.23 1.24 1.25 1. 39 1.45 1.52 1.34 1.39 1.45 thermodynamic relation of available volume. The work will also provide a novel approach for correlating thermoacoustical parameters with available volume and many other related parameters. The necessary experimental data for the computation have been taken from literature.8–9 ~ Introduction The available volume is a very useful quantity, which reflects the extent of intermolecular interactions in liquids and liquid mixtures.The easy and accurate method for its determination provides useful means of studying intermolecular interactions and other thermodynamic properties. Sharma1–3 used expansivity data for calculating various thermoacoustical parameters in polymers, liquefied gases and some organic liquids. It is shown by the author that, expansivity is controlling factor for these thermoacoustical parameters. These parameters have been evaluated in pure liquids at varying conditions by Pandey et al..4–6 Tabhane et al.7 used expansivity data to compute various thermoacoustical parameters in binary liquid mixtures.By the use of such thermoacoustical parameters, available volume can be estimated easily.6 From the literature surveys, it has been found that no attempt has been made to compute available volume in organic liquids and their mixture using thermoacoustical parameters. This paper aims to compute available volume in pure liquids and liquid mixtures at varying temperatures using thermoacoustical parameters and correlate the values obtained with the values obtained from Table 1 Available volume (Va) in pure liquids at various temperatures Liquids T/K Acetone CH3I n-Hexane n-Heptane 253.2 263.2 273.2 283.2 293.2 303.2 308.2 253.2 263.2 273.2 283.2 293.2 303.2 308.2 293.2 313.2 333.2 293.2 313.2 333.2 DOI: 10.1039/b109599d PhysChemComm , 2002, 5(6), 37-39 37 ’ 3.61 3.60 3.59 3.58 3.58 3.57 3.57 3.65 3.63 3.62 3.61 3.60 3.59 3.59 3.58 3.57 3.56 3.58 3.57 3.56 This journal is # The Royal Society of Chemistry 2002 Theoretical The thermal expansivity (a) and absolute temperature (T) can be used to calculate the reduced volume (V�), Moelwyn-Hughes parameter (C1) and Sharma parameter (S*) using the following relations:6 S* C1 1.45 1.47 1.50 1.52 1.55 1.57 1.59 1.39 1.42 1.44 1.46 1.48 1.50 1.52 1.54 1.61 1.68 1.52 1.58 1.65 7.75 7.63 7.52 7.41 7.32 7.23 7.18 8.11 7.96 7.82 7.70 7.59 7.49 7.44 7.34 7.14 6.98 7.40 7.21 7.04 Isochoric temperature coefficient of internal pressure (X) has S~1z4aT X K 20.51 20.50 20.50 20.49 20.48 20.47 20.46 20.53 20.53 20.52 20.51 20.50 20.49 20.49 20.48 20.46 20.43 20.49 20.47 20.44 Paper 3 V~ 1z3(1zaT) C1~13 (1) (2) (3) Eqn.(8) 3 za1T z43 aT 3 Va/1026 m3 mol21 Eqn. (7) 15.09 15.33 15.55 15.82 16.06 15.90 16.42 12.77 12.97 13.16 13.36 13.55 13.75 13.84 28.05 28.90 29.70 31.55 32.48 33.37 13.02 13.88 14.76 15.73 16.73 17.34 18.32 10.57 11.24 11.94 12.68 13.45 14.26 14.68 29.25 33.01 37.15 30.25 33.99 38.07Table 2 Available volume (Va) in binary liquid mixtures of acetone (1) 1 methyl iodide (2) T/K 2 253.2 263.2 273.2 283.2 293.2 303.2 308.2 x0.2 0.4 0.6 0.8 0.2 0.4 0.6 0.8 0.2 0.4 0.6 0.8 0.2 0.4 0.6 0.8 0.2 0.4 0.6 0.8 0.2 0.4 0.6 0.8 0.2 0.4 0.6 0.8 been evaluated using a, molar volume (V), C1 and V�using the following relation: Using the values of a, S* and X, isobaric acoustical parameter (K) and isothermal acoustical parameter (K’) can be calculated using the following relations: The available volume can be deduced using thermoacoustical parameter K’ as: ~VC1 X~{2(1z2aT) K~21 1zS(1azTaT) (5) V V Using thermodynamic relation using critical temperature (Tc), available volume can be computed using the following relation: Fig.1 Available volume in acetone and methyl iodide at various temperatures. a~K’z1 38 PhysChemComm , 2002, 5(6), 37-39 V/1026 m3 mol21 a/1023 K21 68.06 65.95 63.95 61.76 1.32 1.31 1.30 1.27 68.95 66.85 64.75 62.50 1.34 1.33 1.31 1.28 69.85 67.75 65.60 63.29 1.35 1.33 1.32 1.28 70.80 68.66 66.45 64.08 1.36 1.34 1.32 1.29 71.75 69.59 67.32 64.92 1.38 1.36 1.33 1.30 72.72 70.53 68.24 65.80 1.39 1.36 1.34 1.31 73.22 71.02 68.69 66.24 1.41 1.37 1.34 1.31 K aT 1 in displayed have above, mentioned methods ’~21 3zS(1zaT)zX (6) the computed values of available beenvolumes fromFig.bothandthe 2.Available volume is found to increase with increasing Results and discussion The values of some thermoacoustical parameters obtained from expansivity data and the values of available volume obtained from both the methods (eqn. (7) and (8)) are displayed in Tables 1 and 2. The graphical representation of temperature, which seems obvious, as there is increase in molecular motion and decrease in intermolecular attraction at higher temperatures. The values of available volumes from both the methods seem to be in fair agreement. Best agreement is seen at moderate temperatures like 283.2 K for acetone, 293.2 K for methyl iodide, 293.2 K for hexane and 293.2 K for heptane. These results show the applicability of the Fig.2 Available volume in binary liquid mixtures of acetone (1) and methyl iodide (2). V�C1 7.76 7.78 7.81 7.87 1.273 1.271 1.268 1.263 7.65 7.66 7.69 7.76 1.283 1.282 1.279 1.273 7.54 7.56 7.59 7.66 1.294 1.291 1.288 1.282 7.44 7.47 7.50 7.55 1.305 1.301 1.298 1.293 7.35 7.38 7.41 7.47 1.316 1.312 1.308 1.302 7.27 7.30 7.34 7.39 1.327 1.322 1.317 1.311 7.22 7.26 7.30 7.35 1.334 1.328 1.322 1.316 (4) (7) X K Eqn. (7) S* 1.45 1.44 1.44 1.43 20.51 20.52 20.52 20.52 1.47 1.47 1.46 1.45 20.51 20.51 20.51 20.51 1.49 1.49 1.48 1.47 20.50 20.50 20.50 20.51 1.51 1.51 1.50 1.49 20.49 20.49 20.49 20.50 1.54 1.53 1.52 1.51 20.48 20.48 20.49 20.49 1.56 1.55 1.54 1.53 20.47 20.48 20.48 20.48 ’ 3.62 3.62 3.62 3.63 3.60 3.61 3.61 3.61 3.59 3.60 3.60 3.60 3.59 3.59 3.59 3.60 3.58 3.58 3.58 3.59 3.57 3.58 3.58 3.58 3.57 3.57 3.58 3.58 1.58 1.56 1.55 1.54 20.47 20.47 20.48 20.48 V T a~V{ V(1{ T )0:3 Va/1026 m3 mol21 Eqn.(8) 12.59 12.08 11.60 11.10 14.75 14.28 13.84 13.35 13.42 12.88 12.3 5 11.80 14.98 14.51 14.05 13.54 14.28 13.71 13.14 12.55 15.20 14.74 14.26 13.74 15.19 14.58 13.97 13.33 15.44 14.96 14.47 13.94 16.15 15.50 14.83 14.16 15.67 15.19 14.68 14.15 17.15 16.46 15.75 15.03 15.90 15.41 14.90 14.36 17.68 16.96 16.22 15.4 8 16.02 15.53 15.01 14.46 (8) cthermoacoustical parameter for the computation of available volume in pure liquids.In the binary liquid mixture of acetone and methyl iodide (as shown in Table 2 and Fig. 2), there is regular decrease in available volume with increase in mole fraction of methyl iodide. This result is obvious as methyl iodide as a pure component has lower value of available volume than that of acetone. These results prove the applicability of thermoacoustical parameters for the computation of available volume in binary liquid mixtures. References 1 B. K. Sharma, J. Acoust. Soc. Am., 1983, 73, 106–109. 2 B. K. Sharma, Acoust. Lett., 1986, 9, 101. 3 B. K. Sharma, Indian J. Pure Appl. Phys., 1987, 25, 262. 4 J. D. Pandey, N. Tripathi and G. P. Dubey, . Pure Appl. Phys., 1995, 33, 7–11. 5 J. D. Pandey, N Tripathi and R. Dey, Indian J. Phys., 1996, 70B(2), 147–155. 6 J. D. Pandey, G. P. Dubey and R. Dey, Acust. Acta Acust., 1997, 83, 90–92. 7 V. A. Tabhane, S. Ghosh and S. Agrawal, J Pure Appl. Ultrason., 1999, 21, 122–126. 8 D. I. R. Low and E. A. Moelwyn-Hughes, Proc. R. Soc. London, Ser. A, 1962, 267, 384. 9 V. K. Sachdeva and V. S. Nanda, J. Chem. Phys., 1981, 75(9), 4745. PhysChemComm , 2002, 5(6), 37-39 39
ISSN:1460-2733
DOI:10.1039/b109599d
出版商:RSC
年代:2002
数据来源: RSC