article taoufik 2015

Density, Speed of Sound, and Refractive Index Measurements for theBinary Mixture (1, 4Dioxane + Isobutyric Acid) at T = (295.15, 298.15,301.15, 304.15, 307.15, 310.15, and 313.15) KTaoufik Kouissi,*, Adel Toumi, and Moncef Bouanz,

Unite de Recherche de Physique des Liquides et dOptique Non Lineaire, Departement de Physique, Faculte des Sciences de Tunis,Campus Universitaire, 2092 El Manar, TunisiaLaboratoire de Physique des Liquides Critiques, Departement de Physique, Faculte des Sciences de Bizerte, Universite de Carthage,7021 Zarzouna, Tunisia

ABSTRACT: Density, speed of sound, and refractive index for the binarymixture (1,4-dioxane (1) + isobutyric acid (2)) were measured over thewhole composition range at temperatures T = (295.15, 298.15, 301.15,304.15, 307.15, 310.15, and 313.15) K and at the atmospheric pressure.From the experimental data, excess molar volume VE, excess isentropiccompressibility S

E, excess speed of sound cE, excess refractive index nE, molarrefraction R, and deviation in molar refraction R were calculated. Theseresults have been fitted to the RedlichKister polynomial equation. Theexcess molar volume, excess isentropic compressibility, and deviation inmolar refraction were found to be negative, whereas excess speed of soundand excess refractive index were found to be positive for all temperatures.The thermodynamic properties have been discussed in terms of nature ofmolecular interactions between the components of the mixture.

1. INTRODUCTION

1,4-Dioxane and isobutyric acid have the same molecularformula, C4H8O2. They are important organic solvents that canbe used in industrial applications. The determination andprediction of excess thermodynamic properties of liquidmixtures have a great interest for the convenient design ofindustrial processes like distillation and fluid phase separation.1

Moreover, they provide useful information on molecularinteractions required for optimizing thermodynamic modeldevelopment as well as their applications in some branches ofscience. Considerable progress has been made in the theoreticalunderstanding of liquidliquid mixtures.25 It is important toknow the volumetric and ultrasonic properties together withthe refractive index.In this work, the densities, the speed of sound, and refractive

indices for the binary mixture (1,4-dioxane (1) + isobutyric acid(2)) have been measured over the entire composition rangeand in the temperatures range (295.15 to 313.15) K at 3 Kintervals. In addition, to our knowledge, there are no otherpublished data that are available in the literature. From theseexperimental data, excess molar volume, isentropic compressi-bility, excess isentropic compressibility, refractive indexdeviation, excess refractive index, molar refraction, and molarrefraction deviation have been calculated over the entirecomposition range and at each temperature. Excess molarvolume, excess isentropic compressibility, excess speed ofsound, excess refractive index, and molar refraction deviationdata have been correlated using the RedlichKister equation.The thermodynamic properties have been discussed in terms of

the nature of molecular interactions between the componentsof the mixture. This work is a continuation of our researchgroups studies on thermodynamic, transport, and criticalproperties of liquidliquid mixtures.616

2. EXPERIMENTAL PROCEDURE

2.1. Chemicals. 1,4-Dioxane and isobutyric acid wereobtained from Merck with mass purity >99%. All liquids wereused without further purification as indicated in Table 1. Theexperimental values of density, speed of sound, and refractiveindex of pure liquids at temperature T = 298.15 K werecompared with values available in the literature1725 and arelisted in Table 2, which leads to a satisfactory agreement.

2.2. Apparatus and Procedure. All mixtures of 1,4-dioxane and isobutyric acid have been prepared by mixingknown masses of the pure components. The mass is performedby using a digital electronic balance (Sartorius BP 221S) with aresolution of 104 g. The experimental uncertainty in molefractions did not exceed 0.0005. Some care was taken intoconsideration to avoid moisture and dust in the final sample,namely, baking the cells overnight under vacuum and preparingthe mixtures in a dust-free area. The cell, in which theisobutyric acid and 1,4-dioxane were mixed together, wasimmersed in a thermally stabilized water bath with thermal

Received: November 23, 2014Accepted: June 10, 2015

Article

pubs.acs.org/jced

XXXX American Chemical Society A DOI: 10.1021/je5010643J. Chem. Eng. Data XXXX, XXX, XXXXXX
pubs.acs.org/jcedhttp://dx.doi.org/10.1021/je5010643http://pubs.acs.org/action/showImage?doi=10.1021/je5010643&iName=master.img-000.jpg&w=186&h=134

regulation in the order of 103 K over hours. The temperaturewas measured by using a quartz thermometer (HP 2804 A)giving a resolution of 103 K and was calibrated on an absolutescale within 0.01 K. For pure liquid isobutyric acid, the gapbetween the measured value of the speed of sound attemperature T = 298.15 K and that found in the literature isthe order of 47 ms1. This may be due to the measuringinstrument. It is interesting to note that to our knowledge thereis no other value of literature for comparison.2.3. Measurements. Density. Densities of the pure

components and their compositions were measured with anAnton-Paar oscillating U-tube densimeter (DMA 4500 model).The U-cell of the apparatus was calibrated with dry air andtwice-distilled water at atmospheric pressure. The estimateduncertainties are 0.00005 gcm3 for the density and 0.01 K forthe temperature over a wide temperature range.Speed of Sound. Speeds of sound were determined by a

multifrequency ultrasonic interferometer M-81 F (MittalEnterprises, model M-81 F, New Delhi) working at 3 MHz,which was calibrated with water, methanol, and benzene attemperature T = 298.15 K. The precision of the speed of soundmeasurements was estimated to be better than 0.1 ms1. Theestimated uncertainty is better than 0.2 ms1.Refractive Index. Refractive indices of the pure liquids or

mixtures were measured with a thermostatic digital Abberefractometer (Atago, 3T, Tokyo, Japan) at the wavelength ofthe D-line of sodium, 589.3 nm, and atmospheric pressure. Theprecision of the measure is estimated to 104. Temperaturewas controlled by circulating water into the refractometerthrough a thermostatically controlled bath with the digitaltemperature control unit in order to maintain the desiredtemperature within 0.01 K.

3. RESULTS AND DISCUSSION

The experimental values of density for the binary mixture(1,4-dioxane (1) + isobutyric acid (2)) at temperatures T =(295.15, 298.15, 301.15, 304.15, 307.15, 310.15, and 313.15) Kas a function of 1,4-dioxane mole fraction x1 have beenreported in Table 3. The results for the density of the mixtureshow that it decreases with temperature and increases with 1,4-dioxane mole fraction, but the determined isentropiccompressibility increases with temperature and decreases with1,4-dioxane mole fraction.

3.1. Volumetric Properties. The excess molar volumes VE

have been calculated from the experimental density values usingthe following relation:

=

+ V

x M x M x M x M( )E 1 1 2 2 1 11

2 2

2 (1)

where x1, x2; M1, M2; 1 and 2 represent the mole fractions,molecular masses, and densities of components 1 and 2,respectively, is the density of the binary mixture (1,4-dioxane(1) + isobutyric acid (2)). The values of excess molar volumesVE at each temperature from (295.15 to 313.15) K are listed inTable 3.The VE values at each studied temperature obtained from eq

1, have been correlated by the following type of RedlichKisterpolynomial equation at each temperature:26

= =

Y x x A x x( )k

kkE

1 21

1 2(2)

where YE represents an excess or deviation property, subscripts1 and 2 represent the pure components, k is the number offitted parameter and Ak represents the coefficients. Adjustableparameters of Ak were evaluated by least-squares method, andthe values of standard deviation were obtained by the flowingequation:

Table 1. Detailed Description of Chemical Compounds Used

Table 2. Comparison of Experimental and Literature Density (), Refractive Index (n), and Speed of Sound (c) of PureComponents with Available Literature Values at T = 298.15 K and Atmospheric Pressure p = 101.32 kPaa

compd

/(gcm3) n c /ms1

exptl lit. exptl lit. exptl lit.

1,4-dioxane 1.03077 1.028617 1.4197 1.420317 1344.8 134517

1.030518 1.418119 1344.418

1.0246319 1.420120 134320

1.0276020 1.420524

1.0279224 1.41994840

isobutyric acid 0.94222 0.9431921 1.3907 1.3911521 1086 1133.421

0.943122 1.391323

aStandard uncertainties (u) are u() = 0.00005 g.cm3, u(n) = 0.0001, u(c) = 0.2 m.s1, u(T) =0.01 K and u(p) = 0.05 kPa.

Journal of Chemical & Engineering Data Article

DOI: 10.1021/je5010643J. Chem. Eng. Data XXXX, XXX, XXXXXX

B
http://dx.doi.org/10.1021/je5010643http://pubs.acs.org/action/showImage?doi=10.1021/je5010643&iName=master.img-001.png&w=363&h=112

Table 3. Density (), Excess Molar Volume (VE), Speed of Sound (c), Excess Speed of Sound (cE), Isentropic Compressibility(S), and Excess Isentropic Compressibility (S

E) for Various 1,4-Dioxane Mole Fractions x1 of the Binary Mixture (1,4-Dioxane(1) + Isobutyric Acid (2)) at Temperatures T = (295.15, 298.15, 301.15, 304.15, 307.15, 310.15, and 313.15) K andAtmospheric Pressure p = 101.32 kPaa

x1 /gcm3 VE/(cm3mol1) c/(ms1) cE/(ms1) 1010S /(Pa

1) 1010SE/(Pa1)

T = 295.15 K0.0000 0.94528 0 1100.20 0 8.7397 00.1000 0.95563 0.2357 1119.60 140.4949 8.3480 2.59530.2000 0.96546 0.4006 1140.00 241.6894 7.9699 4.92090.3000 0.97508 0.5272 1161.70 318.2238 7.5993 6.89770.4000 0.98420 0.5907 1184.50 375.3356 7.2418 8.37540.5000 0.99305 0.6147 1208.80 417.0557 6.8916 9.27920.6000 1.00152 0.5913 1234.70 442.6543 6.5496 9.46820.7000 1.00956 0.5181 1262.30 447.7030 6.2164 8.79430.8000 1.01723 0.4024 1291.80 421.2622 5.8910 7.13720.9000 1.02438 0.2335 1323.60 327.4653 5.5722 4.29041.0000 1.03086 0 1357.70 0 5.2625 0

T = 298.15 K0.0000 0.94222 0 1086.00 0 8.9989 00.1000 0.95265 0.2469 1105.40 117.8016 8.5907 2.20010.2000 0.96263 0.4289 1125.90 208.7570 8.1948 4.21200.3000 0.97212 0.5456 1147.50 279.3945 7.8122 5.91790.4000 0.98118 0.6056 1170.50 333.7634 7.4389 7.21300.5000 0.98997 0.6259 1194.90 374.0642 7.0748 8.01840.6000 0.99846 0.6059 1220.80 399.6193 6.7202 8.22890.7000 1.00650 0.5338 1248.60 405.5811 6.3729 7.68750.8000 1.01412 0.4152 1278.30 381.2155 6.0345 6.27310.9000 1.02130 0.2490 1310.30 295.8569 5.7030 3.83701.0000 1.02759 0 1344.80 0 5.3810 0

T = 301.15 K0.0000 0.93916 0 1072.10 0 9.2638 00.1000 0.94987 0.2778 1091.50 103.3727 8.8367 1.97760.2000 0.95966 0.4446 1111.90 185.9356 8.4285 3.78260.3000 0.96921 0.5688 1133.60 252.7012 8.0290 5.34840.4000 0.97818 0.6225 1156.60 304.4227 7.6421 6.52920.5000 0.98693 0.6412 1181.10 343.5928 7.2634 7.28160.6000 0.99531 0.6131 1207.20 368.3266 6.8942 7.47700.7000 1.00343 0.5494 1235.00 375.6204 6.5340 7.03950.8000 1.01108 0.4337 1264.90 353.9318 6.1816 5.79180.9000 1.01824 0.2666 1297.10 274.9503 5.8372 3.58941.0000 1.02432 0 1331.90 0 5.5033 0

T = 304.15 K0.0000 0.93610 0 1058.20 0 9.5399 00.1000 0.94687 0.2875 1077.60 95.3919 9.0948 1.88590.2000 0.95670 0.4604 1098.00 173.6014 8.6700 3.62240.3000 0.96621 0.5841 1119.70 237.7226 8.2551 5.13290.4000 0.97519 0.6407 1142.80 288.2373 7.8518 6.28620.5000 0.98397 0.6632 1167.30 326.9898 7.4585 7.03630.6000 0.99236 0.6376 1193.40 351.9363 7.0755 7.25330.7000 1.00047 0.5742 1221.50 360.3312 6.6990 6.86160.8000 1.00810 0.4580 1251.50 340.6816 6.3334 5.68230.9000 1.01519 0.2848 1283.90 265.5399 5.9757 3.55151.0000 1.02105 0 1319.00 0 5.6294 0

T = 307.15 K0.0000 0.93304 0 1043.40 0 9.8446 00.1000 0.94394 0.3042 1062.80 93.8659 9.3789 1.94170.2000 0.95370 0.4731 1083.40 170.9358 8.9333 3.72390.3000 0.96319 0.5974 1105.10 234.1617 8.5013 5.27300.4000 0.97214 0.6532 1128.30 284.1221 8.0802 6.45490.5000 0.98102 0.6877 1152.90 323.4818 7.6690 7.25710.6000 0.98941 0.6630 1179.30 348.9275 7.2673 7.49440.7000 0.99753 0.6015 1207.50 358.2099 6.8754 7.11190.8000 1.00512 0.4821 1237.90 339.9070 6.4925 5.9086



C
http://dx.doi.org/10.1021/je5010643

=

Y Y

n p

( )expE

calE

2 1/2

(3)

where YexpE , Ycal

E , n and p are, respectively, the experimental, thecalculated data, the number of experimental points, and numberof considered parameters. Adjustable parameters of RedlichKister equations Ak and standard deviation values arepresented in Table 4. In this case, the optimum number ofcoefficients Ak was determined from an examination of thevariation of standard deviation, the best fit was obtained byusing only four adjustable fitting coefficients in eq 2.For the binary mixture (1,4-dioxane (1) + isobutyric acid

(2)), the obtained excess molar volume VE values are negativeover the whole composition range at the studied temperatures,as depicted in Figure 1. The sign of excess molar volume VE

depends upon the relative magnitude of contractive andexpansive effects that arise on mixing of the components.27,28

The factors that cause contraction on mixing can be analyzedqualitatively in terms of strong specific interaction, usually akind of chemical interaction, strong physical interaction andgeometrical contributions.28,29 The physical interactionscomprise mainly dispersion forces giving a positive contribu-tion30 such as dipoledipole or dipoleinduced dipoleinteraction between the mixing components.31 The geometricalcontribution is due to the differences in free volumes and molarvolumes between the components.29 The chemical interactionscontribute negatively to the excess molar volume.32,33 Thefactors that causes expansion of volume on mixing of thecomponents can be explained in the terms of dissociation ofone component or both of the components, steric hindrance

due to branching of chains, geometrical mismatch of molecules,and formation of weaker solutesolvent bond than solutesolute and solventsolvent bonds, solventsolvent bonds.31The studied system shows negative excess molar volumes

that increase in magnitude with temperature and with minimadisplayed at the composition x1 = 0.5, as observed in Figure 1.This behavior is explained by the existence of chemicalinteraction (hydrogen bonding) between unlike molecules ofmixture that makes the contraction of solution volume.

3.2. Acoustic Properties. The speed of sound c, excessspeed of sound cE, isentropic compressibility s, and excessisentropic compressibility S

E for the mixture (1,4-dioxane (1) +isobutyric acid (2)) at temperatures T = (295.15, 298.15,301.15, 304.15, 307.15, 310.15, and 313.15) K as a function of1,4-dioxane mole fraction have been reported in Table 3.The analyses for the speed of sound of the mixture show that

this parameter increases with a decrease in the temperature orwith an increase of mole fraction of 1, 4-dioxane; nevertheless,the obtained isentropic compressibility increases with temper-ature and decreases with an increase of 1,4-dioxane molefraction.Through, the use of the speed of sound and density data, the

isentropic compressibilities (S) have been calculated using theLaplaceNewton equation:34

=c1

S 2 (4)

The values of excess isentropic compressibility SE and excess

speed of sound cE have been calculated using the followingrelations:3436

= S S SE id

(5)

Table 3. continued

x1 /gcm3 VE/(cm3mol1) c/(ms1) cE/(ms1) 1010S /(Pa

1) 1010SE/(Pa1)

0.9000 1.01187 0.2806 1270.70 260.9875 6.1205 3.60181.0000 1.01778 0 1306.20 0 5.7587 0

T = 310.15 K0.0000 0.92998 0 1030.80 0 10.1199 00.1000 0.94103 0.3229 1050.10 98.6038 9.6368 2.14100.2000 0.95089 0.5050 1070.60 178.4429 9.1752 4.10810.3000 0.96024 0.6171 1092.30 242.4407 8.7284 5.78480.4000 0.96924 0.6797 1115.40 293.3085 8.2929 7.08360.5000 0.97807 0.7114 1139.90 332.7435 7.8686 7.94340.6000 0.98645 0.6869 1166.30 358.5580 7.4525 8.19840.7000 0.99454 0.6245 1194.50 368.1794 7.0470 7.77650.8000 1.00210 0.5037 1224.90 350.4529 6.6510 6.46900.9000 1.00886 0.3033 1257.70 273.3597 6.2663 3.99651.0000 1.01451 0 1293.30 0 5.8931 0

T = 313.15 K0.0000 0.92692 0 1015.20 0 10.4678 00.1000 0.93811 0.3416 1034.60 108.0344 9.9587 2.50240.2000 0.94793 0.5217 1055.10 192.3067 9.4762 4.773260.3000 0.95722 0.6314 1076.90 258.4557 9.0082 6.69190.4000 0.96621 0.6954 1100.20 310.5789 8.5504 8.17120.5000 0.97503 0.7272 1125.00 350.6963 8.1036 9.13470.6000 0.98345 0.7081 1151.60 377.3253 7.6673 9.42120.7000 0.99162 0.6542 1180.10 388.2674 7.2413 8.95390.8000 0.99914 0.5296 1210.90 370.9913 6.8259 7.44130.9000 1.00592 0.3315 1244.20 295.4479 6.4218 4.66101.0000 1.01124 0 1280.40 0 6.0319 0

aStandard uncertainties (u) are u(x1) = 0.0005, u() = 0.00005 gcm3, u(c) = 0.2 ms1, u(T) = 0.01 K, and u(p) = 0.05 kPa.



D

= c c cE id (6)

the superscript id represents ideal mixture, the values of idealisentropic compressibility S

id and ideal speed of sound cid arecalculated using the following relations:34

= + +

+

T

V

C

V

C

V

C

( ) ( ) ( )

S S S

m p

pm

m p

pm

m p

pm

id1 ,1 2 ,2

1 ,1 ,12

,1

2 ,2 ,22

,2

id id 2

id(7)

= c ( )Sid id id 1/2

(8)

= +id 1 1 2 2 (9)

where the values of the ideal molar volume Vmid, the ideal molar

isobaric heat Cpmid , the ideal isobaric expansivity p

id and the idealdensity id of studied mixture have been calculated respectivelyby the following relations:34

= +V x V x Vm m mid

1 ,1 2 ,2 (10)

= +C x C x Cpm pm pmid

1 ,1 2 ,2 (11)

Table 4. Coefficients Ai and Standard Deviations , Obtained for the Binary Mixture (1,4-Dioxane (1) + Isobutyric Acid (2)) atTemperatures T = (295.15, 298.15, 301.15, 304.15, 307.15, 310.15, and 313.15) K

T/K A0 A1 A2 A3

VE(cm3mol1) 295.15 2.4551 0.0295 0.1963 0.0428 0.00732298.15 2.5071 0.0764 0.3784 0.0945 0.00743301.15 2.5522 0.1063 0.6429 0.0711 0.01205304.15 2.6363 0.0511 0.7498 0.0654 0.01192307.15 2.7255 0.1270 0.7705 0.3848 0.01424310.15 2.8149 0.1061 0.9697 0.3568 0.01071313.15 2.8779 0.1834 1.2244 0.3913 0.01561

cE/(ms1) 295.15 1640.5956 600.1780 1321.6368 1036.5724 8.4370298.15 1473.0577 592.6079 1136.9428 953.0811 7.3444301.15 1352.4609 581.1639 1030.2637 907.3161 6.7161304.15 1286.6539 581.3487 987.1178 892.3238 6.4959307.15 1273.8091 602.1946 974.5676 838.0429 5.5357310.15 1308.4435 596.2466 1049.2407 919.9724 6.5290313.15 1376.2851 597.1285 1184.9375 1042.4277 8.0556

1010SE/(Pa1) 295.15 37.1020 11.2171 1.6948 0.8612 0.0065

298.15 32.0687 10.3009 2.1105 1.5031 0.8729301.15 29.0804 9.7005 2.6056 2.2607 0.0134304.15 28.0903 9.8729 3.0094 2.5556 0.0202307.15 28.9890 10.816 2.9673 1.2505 0.0121310.15 31.7151 11.5205 3.6932 2.1388 0.0068313.15 36.4705 12.8750 4.9438 3.1644 0.0148

nE 295.15 0.0085 0.0002 0.0022 0.0039 0.00002298.15 0.0080 0.0003 0.0031 0.0033 0.00003301.15 0.0076 0.0001 0.0037 0.0039 0.00002304.15 0.0071 0.0001 0.0035 0.0042 0.00001307.15 0.0069 0.0002 0.0039 0.0034 0.00002310.15 0.0064 0.0012 0.0035 0.0009 0.00009313.15 0.0063 0.0013 0.0044 0.0001 0.00010

R/(cm3mol1) 295.15 0.1844 0.0200 0.1361 0.1872 0.00285298.15 0.2167 0.0103 0.2210 0.1715 0.00432301.15 0.2458 0.0073 0.3120 0.1967 0.00347304.15 0.2854 0.0060 0.3285 0.2031 0.00491307.15 0.3143 0.0495 0.3560 0.0632 0.00485310.15 0.3577 0.0909 0.3802 0.0534 0.00514313.15 0.3799 0.1150 0.4844 0.0987 0.00526

Figure 1. Curves of excess molar volume VE against the mole fractionof 1,4-dioxane x1, for the binary mixture (1,4-dioxane (1) + isobutyricacid (2)) at different temperatures (, 295.15 K; red , 298.15 K;blue , 301.15 K; blue , 304.15 K; pink , 307.15 K; green ,310.15 K; blue , 313.15 K). The solid lines represent the valuescalculated from the RedlichKister equation.



E
http://dx.doi.org/10.1021/je5010643http://pubs.acs.org/action/showImage?doi=10.1021/je5010643&iName=master.img-002.jpg&w=239&h=171

= +p p pid

1 ,1 2 ,2 (12)

= +id 1 1 2 2 (13)

where 1, 1, c1, S,1, Vm,1, Cpm,1 , and p,1 are, respectively, thevolume fraction, the density, the speed of sound the isentropiccompressibility, the molar volume, the molar isobaric heat andthe isobaric expansivity of pure 1,4-dioxane, 2, 2, c2, S,2, Vm,2,Cp m,2, and p,2 are the corresponding quantities of pureisobutyric acid. The values of isobaric expansivity have beencalculated from the temperature dependence of the density dataof pure liquids using the relation ((1/)(/T)p) and themolar isobaric heat of pure 1,4-dioxane and pure isobutyric acidat studied temperatures have been estimated by interpolationfrom the literature data.3739

The volume fraction was calculated from the individual puremolar volume Vi and the corresponding mole fraction xi usingthe following relation:

=

x Vx Vii i

i i (14)

The results of excess speed of sound cE versus mole fractionx1 exhibit positive deviations over the entire composition rangeof 1,4-dioxane and temperature as shown in Figure 2. Thepositive deviation in cE indicated the presence of significantinteractions between the molecule of 1,4-dioxane and isobutyricacid.

At a fixed composition, the isentropic compressibility Sincreases systematically with temperature. The mixturebecomes more compressible due to an increase in thermalagitation.21

As shown in Table 3, at a fixed temperature, the isentropiccompressibility values for the binary mixture (1,4-dioxane +isobutyric acid (2)) decrease with an increase 1,4-dioxanecompositionAs depicted in Figure 3, for the studied binary system, the

excess isentropic compressibility values over the entire

composition range are negative. As mentioned in theliterature,34,35,40 the negative values of excess isentropiccompressibility S

E suggest the presence of the dispersion forcesor weak interactions between the component molecules in themixture. Strong molecular interactions occur through chargetransfer, dipoleinduced dipole, and dipoledipole interac-tions, interstitial accommodation, and oriental ordering and alllead to a more compact structure, which makes S

E negative.41,42

In the present studied binary system, the negative SE values may

indicate clustering of isobutyric acid molecules in the presenceof 1,4-dioxane. Furthermore, S

E values decrease with in increasein temperature at fixed 1,4-dioxane composition.

3.3. Optic Properties. The experimental values of therefractive index n, their calculated deviation n, the excessrefractive index values nE, for the binary mixture (1,4-dioxane(1) + isobutyric acid (2)) at temperatures T = (295.15, 298.15,301.15, 304.15, 307.15, 310.15, and 313.15) K as a function of1,4-dioxane composition have been reported in Table 5.The obtained refractive index of the studied binary mixture

increase with the mole fraction of 1, 4-dioxane and decreaseswith the temperature. As mentioned in the literature, theincrease of the refractive indices for the mixture of solvents isexplained as the result of both energetic and structural effects inwhich the enhancement of London disperse forces play animportant role, centered in the dissimilar molecules of themixture.43,44

Refractive index deviation n of mixture has been calculatedusing the suggestions of Fialkov and Fernerly45,46 by means ofthe following equation:

= +n n n n( )1 1 2 2 (15)where n is the refractive index of the mixture, n1 and n2 are,respectively, the refractive indices of 1,4-dioxane and isobutyricacid.The ideal refractive index nid, the ideal refractive index

deviation nid of mixing and the excess refractive index nE, arerespectively defined by43

Figure 2. Curves of excess speed of sound cE against the mole fractionof 1,4-dioxane x1, for the binary mixture (1,4-dioxane (1) + isobutyricacid (2)) at different temperatures (, 295.15 K; red , 298.15 K;blue , 301.15 K; blue , 304.15 K; pink , 307.15 K; green ,310.15 K; blue , 313.15 K). The solid lines represent the valuescalculated from the RedlichKister equation.

Figure 3. Curves of excess isentropic compressibility SE against the

mole fraction of 1,4-dioxane x1, for the binary mixture (1,4-dioxane (1)+ isobutyric acid (2)) at different temperatures (, 295.15 K; red ,298.15 K; blue , 301.15 K; blue , 304.15 K; pink , 307.15 K;green , 310.15 K; blue , 313.15 K). The solid lines represent thevalues calculated from the RedlichKister equation.



F
http://dx.doi.org/10.1021/je5010643http://pubs.acs.org/action/showImage?doi=10.1021/je5010643&iName=master.img-003.jpg&w=239&h=180http://pubs.acs.org/action/showImage?doi=10.1021/je5010643&iName=master.img-004.jpg&w=239&h=188

Table 5. Refractive Index (n), Refractive Index Deviation (n), Excess Refractive Index (nE), Molar Refraction (R) and MolarRefraction Deviation (R) for Various 1,4-Dioxane Mole Fractions x1 of the Binary Mixture (1,4-Dioxane (1) + Isobutyric acid(2)) at Temperatures T = (295.15, 298.15, 301.15, 304.15, 307.15, 310.15, and 313.15) K and Atmospheric Pressure p = 101.32kPaa

x1 n n nE R/(cm3mol1) R/(cm3mol1)

T = 295.15 K0.0000 1.3919 0 0 22.1884 00.1000 1.3955 0.0009 0.0008 22.1266 0.01430.2000 1.3988 0.0014 0.0013 22.0630 0.02960.3000 1.4021 0.0019 0.0018 22.0049 0.03830.4000 1.4052 0.0021 0.0020 21.9493 0.04380.5000 1.4082 0.0022 0.0021 21.8956 0.04650.6000 1.4110 0.0021 0.0020 21.8415 0.04880.7000 1.4137 0.0018 0.0017 21.7927 0.04520.8000 1.4161 0.0011 0.0011 21.7385 0.04620.9000 1.4185 0.0005 0.0004 21.6960 0.03501.0000 1.4211 0 0 21.6770 0

T = 298.15 K0.0000 1.3907 0 0 22.1999 00.1000 1.3942 0.0008 0.0008 22.1312 0.02080.2000 1.3974 0.0013 0.0012 22.0591 0.04390.3000 1.4007 0.0018 0.0017 22.0041 0.04910.4000 1.4038 0.0020 0.0019 21.9498 0.05260.5000 1.4068 0.0021 0.0020 21.8973 0.05340.6000 1.4096 0.0020 0.0019 21.8427 0.05560.7000 1.4122 0.0016 0.0015 21.7892 0.05600.8000 1.4146 0.0010 0.0009 21.7361 0.05540.9000 1.4171 0.0005 0.0004 21.6975 0.03961.0000 1.4197 0 0 21.6826 0

T = 301.15 K0.0000 1.3895 0 0 22.2116 00.1000 1.3929 0.0007 0.0007 22.1311 0.03190.2000 1.3961 0.0012 0.0011 22.0633 0.05020.3000 1.3993 0.0016 0.0015 22.0020 0.06100.4000 1.4024 0.0019 0.0018 21.9497 0.06200.5000 1.4054 0.0020 0.0019 21.8981 0.06130.6000 1.4082 0.0019 0.0018 21.8459 0.06050.7000 1.4107 0.0014 0.0014 21.7859 0.06680.8000 1.4132 0.0010 0.0009 21.7368 0.06150.9000 1.4156 0.0003 0.0003 21.6940 0.04931.0000 1.4183 0 0 21.6882 0

T = 304.15 K0.0000 1.3883 0 0 22.2232 00.1000 1.3916 0.0007 0.0006 22.1361 0.03760.2000 1.3948 0.0012 0.0011 22.0672 0.05590.3000 1.3979 0.0015 0.0014 22.0018 0.06980.4000 1.401 0.0018 0.0017 21.9493 0.06990.5000 1.4039 0.0019 0.0018 21.8923 0.07360.6000 1.4067 0.0018 0.0019 21.8399 0.07190.7000 1.4093 0.0014 0.0014 21.7848 0.07210.8000 1.4117 0.0009 0.0008 21.7314 0.06990.9000 1.4141 0.0003 0.0002 21.6902 0.05511.0000 1.4168 0 0 21.6892 0

T = 307.15 K0.0000 1.3872 0 0 22.2400 00.1000 1.3904 0.0006 0.0005 22.1444 0.04500.2000 1.3936 0.0011 0.0010 22.0770 0.06080.3000 1.3967 0.0015 0.0014 22.0120 0.07320.4000 1.3997 0.0017 0.0016 21.9551 0.07660.5000 1.4026 0.0018 0.0017 21.8957 0.08140.6000 1.4054 0.0017 0.0016 21.8432 0.07870.7000 1.4079 0.0013 0.0013 21.7832 0.08270.8000 1.4103 0.0008 0.0007 21.7307 0.0785



G

= +n n n[ ( ) ( ) ]id 1 12

2 22 1/2

(16)

= +

=

+ + +

n n n n

n n

n n n n

( )

( )

[ ( ) ( ) ]

id id1 1 2 2

1 2 1 22

1 1 2 2 1 12

2 22 1/2

(17)

= n n nE id (18)

In view of eqs 15 and 17, eq 18 leads to the following equation:

= n n nE id (19)

The excess refractive index nE versus mole fraction x1 aregraphically represented in Figure 4. The corresponding curvehas a maximum for all temperatures in composition region 0.3

the result of the ability of the molecules to deform in thepresence of the electric field and the orientation of themolecular dipoles under this field.49 Equation 22 shows thatmolar refraction R, which is directly related to dispersion forces,can be interpreted by the hard core volume for a mole ofmolecules.50 The obtained values of R, listed in Table 5, showthat the mean polarizability of the studied mixture which isweakly affected by temperature, decreases with an increase inconcentration of 1,4-dioxane. The molar refraction thermalbehavior is in agreement with the literature.10,21

The molar refraction deviation R has been calculated usingthe following equation:

= +R R R R( )1 1 2 2 (23)where R1 and R2 are the molar refraction of 1,4-dioxane andisobutyric acid, respectively. The R deviation represents theelectronic perturbation of the molecular orbitals during mixingof the pure liquids; its sign and magnitude give indication aboutthe mixing phenomenon.51,52

The results in molar refraction deviation R for the binarymixture (1,4-dioxane (1)+ isobutyric acid (2)) at temperaturesT = (295.15, 298.15, 301.15, 304.15, 307.15, 310.15, and313.15) K are reported in Table 5 and represented in Figure 5.

This shows that the molar refraction deviation R versus molefraction x1 are negative highlighting the presence of strongintermolecular interactions between the compounds ofmixture.53,54

The variation of excess speed of sound cE, excess isentropiccompressibility S

E, excess refractive index nE, and molarrefraction deviation R were correlated with the RedlichKister equation (eq 2), for the studied mixture. The coefficientsAk, and standard deviations , obtained for this system atdifferent temperatures are reported in Table 4. In all cases, theoptimum number of coefficients Ak was determined from anexamination of the standard deviation variation, and the best fitwas obtained by using only four adjustable fitting coefficients ineq 2.

4. CONCLUSIONIn this paper, density , speed of sound c, and refractive index nhave been measured over the whole composition range attemperatures T = (295.15, 298.15, 303.15, 308.15, and 313.15)K for the binary mixture (1,4-dioxane (1) + isobutyric acid(2)). From these experimental data, excess molar volume VE,excess speed of sound cE, isentropic compressibility S, excess ofisentropic compressibility S

E, deviation in refractive index n E,molar refraction R, and deviation in molar refraction R werecalculated and correlated with the RedlichKister polynomialequation to derive the coefficients Ak, and standard deviations.The excess molar volume, excess isentropic compressibility,

and deviation in molar refraction are negative over the entirerange of composition at all temperatures, but excess speed ofsound and excess refractive index are positive.The excess or derivation functions are used to interpret the

thermodynamic properties in terms of intermolecular inter-actions between the components of the studied binary mixture.The interactions, which are expected to occur between 1,4-dioxane and isobutyric, may be the hydrogen bonding betweenthe oxygen atoms of 1,4-dioxane and the hydrogen atoms of theOH groups of isobutyric acid molecules, dipoledipoleinteraction between unlike molecules, and dispersion forcesthat likely exist within the system.

AUTHOR INFORMATIONCorresponding Author*E-mail: [email protected] (T.K.).NotesThe authors declare no competing financial interest.

REFERENCES(1) Rathnam, M. V.; Ambavadekar, D. R.; Nandini, M. Densities,viscosities, and sound speed of binary mixtures of hexyl acetates withtetrahydofuran, 1, 4-dioxane, anisole, and butyl vinyl ether. J. Chem.Eng. Data 2013, 58, 33703377.(2) Rajgopal, K.; Chenthilnath, S. Study on excess thermodynamicparameters and theoretical estimation of ultrasonic velocity of 2-methyl 2-propanol with nitriles at different temperatures. J. Chem. Eng.Data 2010, 18, 806816.(3) Anil, K. N. Ultrasonic and viscometric study of molecularinteractions in binary mixtures of aniline with 1-propanol, 2-methylpropanol at different temperatures. Fluid Phase Equilib. 2007, 259,218227.(4) Shahla, P.; Divya, S.; Shashi, S.; Singh, K. P.; Manisha, G.; Shukla,J. P. Ultrasonic velocity, density, viscosity and their excess parametersof the binary liquid mixtures of tetra hydro Furan with methanol ando- crysol at varying temperatures. Appl. Acoust. 2009, 70, 507513.(5) Rajgopal, K.; Chenthilnath, S. Excess parameters studies onbinary liquid mixtures of 2-methyl 2-propanol with aliphatic nitriles atdifferent temperatures. J. Mol. Liq. 2011, 160, 7280.(6) Kouissi, T.; Bouanz, M.; Ouerfelli, N. KCl-Induced phaseseparation of 1, 4-dioxane + water mixtures studied by electricalconductivity and refractive index. J. Chem. Eng. Data 2009, 54, 566573.(7) Kouissi, T.; Bouanz, M. Transport properties in 1,4-dioxane +water + saturated KCl critical mixture by measuring viscosity andelectrical conductivity. J. Chem. Eng. Data 2010, 55, 320326.(8) Toumi, A.; Bouanz, M. Critical behavior of the binary-fluidisobutyric acid-water with added ion (K+, Cl). Eur. Phys. J. E 2000, 2,211216.(9) Toumi, A.; Bouanz, M.; Gharbi, A. Coexistence curves of thebinary mixture isobutyric acid-water with added ions (K+, Cl). Chem.Phys. Lett. 2002, 362, 567573.

Figure 5. Curves of molar refraction deviation R against the molefraction of 1,4-dioxane x1, for the binary mixture (1,4-dioxane (1) +isobutyric acid (2)) at different (, 295.15 K; red , 298.15 K; blue, 301.15 K; blue , 304.15 K; pink , 307.15 K; green , 310.15K; blue , 313.15 K). The solid lines represent the values calculatedfrom the RedlichKister equation.



I
mailto:[email protected]://dx.doi.org/10.1021/je5010643http://pubs.acs.org/action/showImage?doi=10.1021/je5010643&iName=master.img-006.jpg&w=239&h=178

(10) Toumi, A.; Bouanz, M. Volumetric and refractive indexproperties of isobutyric acid- water binary mixtures at temperaturesranging from 300.15 to 313.15 K. J. Mol. Liq. 2008, 139, 5560.(11) Toumi, A.; Bouanz, M. Effect of the (K+, Cl) ions on the orderparameters and on the LorentzLorenz relation in the isobutyricacidwater critical mixture. J. Mol. Liq. 2005, 122, 7483.(12) Hadded, N.; Bouanz, M. Excess molar heat capacity of isobutyricacidwater binary liquid mixtures near and far away from the criticaltemperature. J. Mol. Liq. 2007, 130, 1114.(13) N. Ouerfelli, N.; Kouissi, T.; Zrelli, N.; Bouanz, M. Competitionof viscosity correlation equations in isobutyric acid + water binarymixtures near and far away from the critical temperature. J. SolutionChem. 2009, 38, 9831004.(14) Ouerfelli, N.; Kouissi, T.; Iulian, Olga The relative reducedRedlich-Kister and Herraez equations for correlating viscosities of 1,4-dioxane +water mixtures at temperatures from 293.15 to 323.15 K. J.Solution Chem. 2010, 39, 5775.(15) Hafaiedh, N.; Toumi, A.; Bouanz, M. Dynamic viscosity study ofbinary mixtures triethylamine + water at temperatures ranging from(283.15 to 291.35) K. J. Chem. Eng. Data 2009, 54, 21952199.(16) Toumi, A.; Hafaiedh, N.; Bouanz, M. Thermodynamicproperties of triethylamine +water liquid mixture from shear viscositymeasurements. Fluid Phase Equilib. 2009, 278, 6875.(17) Baragi, J. G.; Aralaguppi, M. I.; Aminabhavi, T. M.;Kariduraganavar, M. Y.; Kulkarni, S. K. Density, viscosity, refractiveindex, and speed of sound for binarymixtures of 1,4-dioxane withdifferent organic liquids at (298.15, 303.15, and 308.15) K. J. Chem.Eng. Data 2005, 50, 917923.(18) Rajesh, K. D.; Mahendra, N. R. Study on solutionsolutioninteractions prevailing in some liquid mixtures by volumetric,viscometric and acoustic measurements. Phys. Chem. Liq. 2014, 52,5577.(19) Nayak, J. N.; Aralaguppi, M. I.; Naidu, B. V. K.; Aminabhavi, T.M. Thermodynamic properties of water + tetrahydrofuran and water +1,4-dioxane mixtures at (303.15, 313.15, and 323.15) K. J. Chem. Eng.Data 2004, 49, 468474.(20) Nayak, J. N.; Aralaguppi, M. I.; Aminabhavi, T. M. Density,viscosity, refractive index and speed of sound in the binary mixture of1,4-dioxane + ethanediol, + hexane, + tributylamine, or + triethylamineat (298.15, 303.15 and 308.15) K. J. Chem. Eng. Data 2003, 48, 11521156.(21) Indra, B.; Nirmala, D.; Paramespri, N.; Deresh, R. Density speedof sound and refractive index measurements for the binary systems(Butanoic acid + Propanoic acid or 2-Methyl-propanoic acid) at T =(293.15 to 3313.15) K. J. Chem. Thermodyn. 2013, 57, 203211.(22) Letcher, T. M; Redhi, G. G. Thermodynamic excess propertiesfor binary mixtures of (Benzonitrile + a carboxylic acid) at T =298.15K. Fluid Phase Equilib. 2002, 198, 257266.(23) Letcher, T. M; Redhi, G. G. Phase equilibria for liquid mixturesof (Butanenitrile + Carboxylic acid + Water) at T = 298.15K. FluidPhase Equilib. 2002, 193, 123133.(24) Ciocirlan, O.; Croitoru, O.; Iulian, O. Density and refractiveindex of binary mixtures of two 1-Alkyl-3-methylimidazolium ionicliquids with 1,4-dioxane and ethylene glycol. J. Chem. Eng. Data 2014,59, 11651174.(25) Giner, B.; Lafuente, C.; Villares, A.; Haro, M.; Lopez, M. C.Volumetric and refractive properties of binary mixtures containing 1,4-dioxane and chloroalkanes. J. Chem. Thermodyn. 2007, 39, 148157.(26) Redlich, O.; Kister, A. T. Algebraic representation ofthermodynamic properties and the classification of solutions. Ind.Eng. Chem. 1948, 40, 345348.(27) Almassi, M. Densities and viscosities of the mixtures(formamide + 2-alkanol): Experimental and theoretical approaches.J. Chem. Thermodyn. 2014, 69, 101106.(28) Muhammad, A. S.; Shamim, A.; Shamsuddin, M. A.;Mohammad, H. U. Excess Molar Volumes and Thermal Expansivitiesof Aqueous Solutions of Dimethylsulfoxide, Tetrahydrofuran and 1,4-Dioxane. Phys. Chem. Liq. 2002, 40, 621635.

(29) Rathnam, M. V.; Ambavadekar, D. R.; Nandini, M. Densities,viscosities and sound speed of binary mixtures of hexyl acetate withtetrahydofuran, 14-dioxane, anisole and butyl vinyl ether. J. Chem. Eng.Data 2013, 58, 33703377.(30) Contreras, M. Densities and Viscosities of Binary Mixtures of1,4-Dioxane with 1-Propanol and 2-Propanol at (25, 30, 35, and 40)C. J. Chem. Eng. Data 2001, 46, 11491152.(31) Jain, P.; Signh, M. Density, viscosity of binary liquid mixtures ofpropylene carbonate with polar and nonpolar solvents. J. Chem. Eng.Data 2004, 49, 12141217.(32) Dubey, G. P.; Kumar, K. Densities, viscosities and speeds ofsound of binary liquid mixtures of ethylenediamine wih alcohols atT=(293.15 to 313.15) K. J. Chem. Eng. Data 2011, 56, 29953003.(33) Estrada-Baltazar, A.; Iglesias-Silva, G. A.; Caballero-Ceron, C.Volumetric and Transport Properties of Binary Mixtures of n-Octane+Ethanol, + 1-Propanol, + 1-Butanol, and + 1-Pentanol from (293.15to323.15) K at Atmospheric Pressure. J. Chem. Eng. Data 2013, 58,33513363.(34) Douheret, G.; Davis, M. L.; Reis, J. C. R.; Blandamer, M. J.Isentropic compressibilities- experimental origin and the quest for theirrigorous estimation in thermodynamically ideal liquid mixtures.ChemPhysChem 2001, 2, 148161.(35) Douheret, G.; Morau, C.; Viallard, A. Excess thermodynamicquantities in binary systems of non electrolytes: Different ways ofcalculating excess compressibilities. Fluid Phase Equilib. 1985, 22,277287.(36) Douheret, G.; Davis, M. L.; Reis, J. C. R. Excess isentropiccompressibility and excess ultrasound speed in binary and ternaryliquid mixtures. Fluid Phase Equilib. 2005, 231, 246249.(37) Ricardo, F. C.; Pedro, L. O. V. Measurements of the Molar HeatCapacities and Excess Molar Heat Capacities for Water + OrganicSolvents Mixtures at 288.15 to 303.15 K and Atmospheric Pressure. J.Solution Chem. 2010, 39, 259276.(38) Biros, J.; Sikora, A.; Zivny, A.; Pouchly, J. Heat capacity ofmonomer models of some hydrophilic polymers in aqueous solutionfrom 20 to 60C. Collect. Czech. Chem. Commun. 1982, 47, 26922701.(39) Konicek, J.; Wadso, I. Thermochemical properties of somecarboxylic acids, amines and N-substituted amides in aqueous solution.Acta Chem. Scand. 1971, 25, 15411551.(40) Kumar, H.; Sharma, S. Acoustical studies of binary liquidmixtures of cylopentane with 1-Alkanol at different temperatures anddifferent approaches for ideal mixing lows. J. Solution Chem. 2010, 39,967986.(41) Victor, P. J.; Das, D.; Hazra, D. K. Excess molar volumes,viscosity deviations and isentropic compressibility changes in binarymixtures of N,N-dimethylacetamide with 2-methoxy ethanol and waterin the temperature range 298.15 to 318.15 K. J. Indian Chem. Soc.2004, 81, 10451050.(42) Pal, A.; Kumar, H.; Maan, R. M.; Sharma, H. K. Volumetric andultrasonic studies of molecular interactions in n-Alkoxypropanols +Alkyl Acetates mixture at different temperatures. J. Chem. Eng. Data2013, 58, 31903200.(43) Reis, J. C. R.; Lampreia, I. M. S.; Santos, A. F. S.; Moita, M. L. C.J.; Douheret, G. Refractive index of liquid mixtures: Theory andexperiment. ChemPhysChem 2010, 11, 37223733.(44) Marlon, M. R.; Eliseo, A. G.; Wilfred, G. J. Experimental Studyand Modelling of the Refractive Indices in Binary and TernaryMixtures of Water with Methanol, Ethanol and Propan-1-ol at 293.15K. J. Solution Chem. 2015, 44, 206222.(45) Fialkov, Yu. Ya.; Fenerli, G. N. Use of volume properties in thephysicochemical analysis of binary liquid systems. Russ. J. Inorg. Chem.1964, 9, 12051209.(46) Fialkov, Yu. Ya. Molar-additive properties in the physicochem-ical analysis of binary liquid systems. Russ. J. Phys. Chem. 1967, 41,398400.(47) Aleksandra, Z. T.; Bojan, D. D.; Dusan, K. G. Use of mixingrules in predicting refractive indices and specific refractivities for somebinary liquid mixtures. J. Chem. Eng. Data 1992, 37, 310313.



J

(48) Born, M.; Wolf, E. Principles of Optics; Pergamon Press: Oxford,1983.(49) Teodorescu, M.; Secuianu, C. Refractive Indices Measurementand Correlation for Selected Binary Systems of Various Polarities at25C. J. Solution Chem. 2013, 42, 19121934.(50) Encina, C.; Adela, P.; Mercedes, P.; Ramon, B.; Alfredo, A.Refractive Indices and Surface Tensions of Binary Mixtures of 1,4-Dioxane + 1-Alkanols at 298.15 K. J. Chem. Eng. Data 2001, 46, 692695.(51) Adela, P.; Encina, C.; Mercedes, P.; Alfredo, A.; Ramon, B.Refractive Indices and Surface Tensions of Binary Mixtures of 1,4-Dioxane + n-Alkanes at 298.15 K. J. Chem. Eng. Data 2000, 45, 682685.(52) Tejraj, M. A.; Hemant, T. S. P.; Rajashekhar, S. K.; Bindu, G.;Keith, C. H. Densities, refractive indices, speeds of sound, and shearviscosities of diethylene glycol dimethyl ether with ethyl acetate,methyl benzoate, ethyl benzoate, and diethyl succinate in thetemperature range from 298.15 to 318.15 K. J. Chem. Eng. Data1994, 39, 251260.(53) Bahadur, I.; Deenadayalu, N.; Naidoo, P.; Ramjugernath, D.Volumetric, acoustic and refractive index for the binary system(Butyric acid + Hexanoic acid) at different temperatures. J. SolutionChem. 2014, 43, 787803.(54) Gupta, M.; Vibhu, I.; Shukla, J. P. Refractive index, molarrefraction deviation and excess molar volume of binary mixtures of 1,4-dioxane with carboxylic acids. Phys. Chem. Liq. 2010, 48, 415427.



K

article taoufik 2015

Documents