Investigation of acoustical excess parameters and FTIR studies for binary liquid mixtures of tetrachloroethylene and cyclopentanone at different temperatures.

Speed of sound (U), Density (ρ), and viscosity (η) values of liquid mixtures of Tetrachloroethylene with Cyclopentanone and pure liquids were determined at regular intervals of molar range at different temperatures (303.15, 308.15, 313.15, 318.15) K. From the experimentally determined values, thermo-acoustic parameters such as excess molar volume (VE) and excess free length (Lf E), excess Gibb’s free energy (ΔGE) and excess enthalpy (HE) have been estimated. The variations of the above parameters discussed based on intermolecular interactions existing in this binary mixture. The computed values of sound speed in the mixture from various theories are compared with experimentally calculated values and have a clear check to validate the theories for the present system, and FTIR studies provide detailed analysis of molecular interactions.


Introduction
The volumetric and viscometry survey together with Speed of sound of liquid mixtures are of significant parameters and play a vital role in realizing the intermolecular interactions obtained in and around the molecules of finding large usage in various manufacturing technological industries 1,2 .Diverse scholarly articles found with density, viscosity, and speed of sound calculations for huge range of binary liquid mixtures contain ketones as one of the components [3][4][5][6][7][8] and these tracts were construed in terms of specific and nonspecific interactions.
Ketones are tinted for dipoledipole interactions and hydrogen bonding.Ketones have a key role for their applications in chemistry, biology and interaction studies of hydrogen and other liquid bindings.This study reveals that ketone molecules play a vital role in forming hydrogen bonding among molecules.In depth investigation of molecular association in liquids related to aromatic functional group with various functional groups is carried out in this study.The study of thermodynamic properties of multi component mixtures and other different computational models are beneficiary for pharmaceutical and other industries applications 9 .
The functional parameters of thermodynamics were sensitively depending on various intermolecular IOP Publishing doi:10.1088/1742-6596/2765/1/012012 2 forces and on size and shape 10 .From the determined values of speed of sound and viscosity and density, we will extract the excess thermo-acoustic parameters like excess ultrasonic velocity (U E ), excess adiabatic compressibility (β ad E ), excess molar volume (V E ), excess free length (Lf E ), excess Gibb's free energy (G E ) and excess enthalpy (H E ).Now this current epilogue shows the speed of sound and viscosity values had been a huge empirical bondage in the liquid.In this study the results were discussed for liquid mixtures of tetrachloroethylene with cyclopentanone at temperatures of (303.15,308.15, 313.15 and 318.15)K. FT-IR spectra of binary mixtures were obtained at room temperature for different compositions and pure liquids.The FT-IR spectroscopy is one of the tools to identify the strength of interactions, type of bonding and existence of hydrogen bond with shape of the absorption peaks and frequency shift of the band.

Materials
Tetrachloroethylene (TCE) with cyclopentanone is used in this study which was AR grade obtained from Merck Co. Inc., Germany, by 99% purity with a standard purified method 11 .

Measurements
By amalgamation of all these chemical mixtures were kept in observation in air tight bottles for 72 hours' for viscosity, velocity and density measurements.Viscosity was measured by using Ostwald viscometer.The uncertainty in viscosity measurement is up to 0.001mPa-s.For measurement of density was accurately using 10 ml specific gravity bottles.The average uncertainty in the measured density is ±0.001 kg/m 3 .The speed of sound is measured with a single crystal variable path interferometer operating at a frequency of 2MHz that had been calibrated tetrachloroethylene with and cyclopentanone used for collecting the different temperatures.The FT/IR-6000 FT-IR spectrometer was used to get the data of binary mixtures.

Computational Details
The values of experimentally determined density and speed of sound for the binary mixtures of tetrachloroethylene with cyclopentanone at 303.15 K, 308.15 K, 313.15 K, and 318.15K for different compositions.
In the present work under study by using formulas excess values were calculated by using the expressions given in literature 12 as follows,

Excess free length
Lf E = Lf -KT (Ks)

Results and discussion
The comparison experimental values and literatures of speed of sound(u), density(ρ) and viscosity (η) in case of the binary liquid mixture (Tetrachloroethylene + Cyclopentanone) under study at temperatures, T =303.15K are given in Table 1.From the above Table1 stated the literature survey and from Table 2 and Table 3 we get the value of parameters and also excess parameters of binary mixtures contain tetrachloroethylene with From Figure-1, the presence of strong interactions in these mixtures is confirmed through the negative values.This sign of the excess ultrasonic velocity (U E ) plays a significant role in the compactness of association among molecules in liquid mixtures through charge transfer, dipoledipole interaction between different molecules of different shapes and size stated by fort et al 20 .
Figure-2 indicates the corresponding graphs against the binary liquids of tetrachloroethylene with cyclopentanone can be visualised the action of binary mixtures at various temperatures.As it was stated that more negative variation of excess adiabatic compressibility(β ad E ) 21 is observed.Jacobson observed the alteration in free length by the values adiabatic compressibility assigned to strong interaction.The dispersion forces indicate the vigour interaction had stated by fort and more 22 .
Figure-3 shows the excess enthalpy (H E ) which designates the behaviour of fluids in clarifying the internal structure.The complex information of H E is important in chemistry, and other biological branches.It also reveals the depth and type of the molecular collaborations and signifies the energy of the hydrogen bonding.Positive values of H E indicates vital interactions among the components in liquids 23,24 .Increasing content of TCE marks that dispersion compels in the liquids and molecules 25 and confirms the significance of feeble dipole-dipole interactions in this system 26 .
From figure-4, in a keen observation it reveals that L f E values had negative pattern corresponding to what observed in the study U E .The negative values of L f E indicate particular interactions among dissimilar molecules 27 .The variation of excess molar volume (V m E ) with the mole fraction X1 is mentioned in figure 5.This intermolecular association will be explained by using the magnitude and sign of V m E .In this case study the V m E values are highly negative and might be attributed to the establishment of hydrogen bond and breaking of alcohol self-association.It is a clear result of geometrical fitting of molecules of different size and structure of different components within the mixture.These intermolecular forces of attraction in a molar volume can be affected by temperature increase is connected to the presence of weakening of forces 28 by Garcia et all 29,30 and similar corresponding works were observed by previously observed due to thermal agitation.
From Figure-6, the excess Gibb's free energy of activation (G E ) shows positive changes with changes in mole fraction and increasing values with temperature.G E variation indicates the presence of hydrogen bonding among constituent component molecules under study 31 .This property was used in desulfurization of sulphur coals, since the removal rate of organic sulphur become higher in Tetrachloroethylene solvents 32 .
Computed values of speed of sound in the liquid mixtures with various relations like Impedance dependence relation, Nomoto's relation, Junjie's theory, Ideal mixing relation, Rao's specific velocity relation and free length theory over the whole mole fraction range of tetrachloroethylene at certain temperatures are given in Table 5.It is observed that the positive percentage deviation for Rao's theory and in other theoretical values it is negative.Thus, experimental data of free length theory is well suited for this mixture.In all the theories, the deviations of ultrasonic velocity represent strong interactions.The occurrence of negative deviations in five models confirms the presence of strong hydrogen bonding between the components.From Fig. 7 the interaction parameter also positive denotes the strong possible interactions.The value of U exp 2 /U imx 2 disperses with temperature and the interaction between dissimilar molecules reduces with increasing temperature.

FT-IR Studies on Tetrachloroethylene with Cyclopentanone binary mixtures
The solution structure and physical information about intermolecular interactions can be investigated using the spectroscopic technique like IR which also gives information about the functional groups that are influenced by the surrounding condensed medium 33 .The infrared spectra are recorded for the one binary mixture Cyclopentanone at room temperature of 298.15K as a function of the composition of TCE to study of interactions of the molecules between the binary liquid mixtures.It is observed from the recorded infrared spectra of TCE that the C=C Bending band is at 902.77 cm -1 with the C-Cl stretching at 775.10 cm -1 .Continuous change is observed in the frequency of IR bands varies on mixing Tetrachloroethylene + Cyclopentanone binary liquid mixture for different concentrations.
The observed band frequency value of C=O stretching is changed from 1728 cm -1 and maximum frequency deviation is observed at equal composition of constituent liquids.It is observed that strong interactions exist between tetrachlorethylene and Cyclopentanone binary liquid mixture.The variation of excess thermodynamic factors discussed on focussing the interactions is confirmed by the IR data [32][33][34][35] .

Conclusions
In the present study, it reveals that all the excess parameters like U E , V m E , β ad E , L f E .and H E , G E is computed from the determined speed of sound(u), density(ρ) and viscosity(η) values and the creation of hydrogen bonds among the molecules of all mixtures is identified.The excess molar volume had slightly changed from positive to negative for the binary system.This is an apt sign for the proximity of hydrogen bonding with that of other, various theories that were correlated with the experimental values.Speed of sound values was obtained with free length theory relation is in good agreement with the experimental value.As a common conclusion, it can be said that the FTIR spectral analysis in the liquid mixtures of Tetrachlorethylene studied are supported well by the experimental results from excess acoustical and thermodynamic techniques.This is confirmed by the presence of strong interactions.

Acknowledgements
The author expresses his gratitude to Prof. K. Samatha, for continuous support in carrying out experimental work and conveys special thanks to HOD, Department of Physics for providing Lab facilities.