Densities, Speeds of Sound, Excess Molar Enthalpies, and Heat

Article pubs.acs.org/jced

Densities, Speeds of Sound, Excess Molar Enthalpies, and Heat Capacities of o-Chlorotoluene and Cyclic Ether Mixtures V. K. Sharma* and R. Dua Department of Chemistry, Maharshi Dayanand University, Rohtak 124001, India S Supporting Information *

ABSTRACT: The densities, ρ, speeds of sound, u, and excess heat capacities, CEP data of binary mixtures formed by o-chlorotoluene with 1,3-dioxolane or 1,4-dioxane or tetrahydropyran at (298.15, 303.15, and 308.15) K and excess molar enthalpies, HE, of the same mixtures at 308.15 K have been measured over the entire composition range at atmospheric pressure. The excess molar volumes, VE, and excess molar isentropic compressibilities, κES , data have been calculated from experimental densities and speeds of sound data. The VE, κES , and HE values for o-chlorotoluene (1) + 1,3-dioxolane or 1,4-dioxane (2) mixtures are positive, and those for o-chlorotoluene (1) + tetrahydropyran (2) mixture are negative over whole range of composition. However, CEP values for the studied mixtures are positive over the entire range of composition. The VE, κES , HE, and CEP data have been estimated in terms of graph and Prigogine−Flory−Patterson (except CEP data) theories. The results indicate that VE, κES , HE, and CEP values estimated via graph theory are in agreement with experimental values.

1. INTRODUCTION Thermodynamic properties of liquid mixtures provide information about the nature and extent of molecular interactions existing in mixtures along with their use in the development and design of chemical engineering processes. The increasing use of cyclic ethers in many industrial processes like pharmaceuticals, cosmetics, and separation processes in chemical plants has enhanced the need of thermodynamic data on mixtures of cyclic ethers and organic solvents.1,2 Oxygenated liquids are generally added to gasoline to improve octane number and reduce pollution.3 o-Chlorotoluene is used in the production of chlorobenzyl chloride, 2-chlorobenzaldehyde, and 2-chlorobenzoic acid which in turn are used as precursors in the production of optical brighteners, dyes, pharmaceuticals, and fungicides.4 Any process like simulation of the synthesis, purification, or gasoline blending, prior to the design stage needs a thermodynamic model for the description of the physical behavior. The thermodynamic properties of liquid mixtures are required to improve the various parameters involved in thermodynamic models. Our research group is carrying out a research project on thermodynamic and topological characterization of multicomponent mixtures containing cyclic ether as an oxygenated additive5−8 with organic solvent with the purpose of providing thermodynamic data and testing of thermodynamic models for the solutions. A literature survey showed that no data on thermodynamic properties for the mixtures of o-chlorotoluene (1) + 1,3-dioxolane or 1,4-dioxane or tetrahydropyran (2) were reported. In the present studies, we report here excess molar volumes, VE, excess molar enthalpies, HE, excess isentropic compressibilities, κES and excess heat capacities, CEP for the investigated mixtures. © 2014 American Chemical Society

2. EXPERIMENTAL SECTION o-Chlorotoluene (o-CT) (Fluka, mass fraction, 0.990), 1,3dioxolane (D) (Fluka, mass fraction, 0.992), 1,4-dioxane (D/) (Fluka, mass fraction, 0.991), and tetrahydropyran (THP) (Fluka, mass fraction, 0.992) were purified by standard methods. o-CT was washed successively with concentrated sulfuric acid, water, 10% sodium carbonate, and water and then dried over calcium chloride and fractionally distilled.9 1,3-Dioxolane (D) was purified10 by refluxing with lead(IV) oxide, cooled, and filtered. Xylene and more lead(IV) oxide were added, and the mixture was fractionally distilled. The main fraction (collected at (70 to 71) °C) was treated with xylene, redistilled, and then dried over sodium wire, and finally the fraction (boiling at (74 to 75) °C) was collected. 1,4-Dioxane (D/) was purified11 by heating with concentrated HCl and water (for about (6 to 12) h by passing a slow stream of nitrogen) and then treated with KOH pellets, refluxed, and finally fractionally distilled over sodium. Tetrahydropyran (THP) was purified10 by repeated vacuum distillation, and the middle fraction was collected each time. Details of studied chemicals, the source, purification method, initial purity, final purity, and analysis method are presented in Table 1. The densities and speeds of sound values of the purified liquids are reported in Table 2.1,3,9,12−24 The densities and speeds of sound of pure liquids and their mixtures were measured using an Anton Paar vibrating tube digital density and sound analyzer (DSA-5000) in the manner as explained elsewhere.25,26 The measurements are based on Received: August 8, 2013 Accepted: January 30, 2014 Published: February 7, 2014 684

dx.doi.org/10.1021/je400722h | J. Chem. Eng. Data 2014, 59, 684−695

Journal of Chemical & Engineering Data

Article

The samples of (1 + 2) binary mixtures for IR studies were prepared by mixing components in 1:1 (w/w) ratio, and their IR spectra were recorded on Perkin-Elmer spectrum RX-1, FTIR spectrometer.

Table 1. Details of Studied Chemicals, Source, Initial Purity, Purification Method, Final Purity, and Analysis Method

a

chemical name

source

initial purity

purification method

final purity

analysis method

o-chlorotoluene

Fluka

0.985

0.990

GCa

1,3-dioxolane

Fluka

0.984

0.992

GC

1,4 dioxane

Fluka

0.983

0.991

GC

tetrahydropyran

Fluka

0.987

fractional distillation fractional distillation fractional distillation vacuum distillation

0.992

GC

3. RESULTS The experimental densities, ρ, and speeds of sound, u, data of o-CT (1) + D or D/ or THP (2) mixtures as a function of composition at (298.15, 303.15, and 308.15) K are listed in Table 3. Excess molar volumes, VE, isentropic compressibilities, κS, and excess isentropic compressibilities, κES , were estimated from the measured ρ and u data using the following eqs:

GC = gas chromatography.

2

VE =

measuring the period of oscillation of a vibrating U-shaped hollow tube filled with the sample. The calibration of the apparatus was carried out with the double-distilled, deionized water before each series of measurements. The uncertainties in the density and speed of sound measurements are 0.5 kg·m−3 and 0.1 m·s−1, respectively. The uncertainty in calculated VE values is 0.1 %. Molar heat capacities, CP, of the pure liquids, excess heat capacities, CEP , and excess molar enthalpies, HE, of present mixtures were measured by using a micro differential scanning calorimeter (model-μ DSC 7 Evo) supplied by M/S SETARAM instrumentation, France in the manner as described in the literature.27,28 The heat capacities of the pure liquids are reported (in Table 2) and also compared with their literature values.1,15,19,29−31 The uncertainty in the measured CEP and HE values are 0.3 % and 1 %, respectively.

⎡1

∑ ⎢⎢ i=1

⎣ρ

−

1⎤ ⎥xiMi ρi ⎥⎦

(1)

1 ρu 2

(2)

κSE = κS − κSid

(3)

κS =

where xi, Mi, and ρi are the mole fraction, molar mass, and density of pure component (i) respectively and ρ and u are the density and speed of sound of the mixture. The κidS values were obtained by employing Benson and Kiyohara32 eq κSid =

2

⎡

i=1

⎣

2 (∑ φα )2 Tviαi2 ⎤ ⎥ − T (∑ xivi) 2i = 1 i i CP , i ⎥⎦ (∑i = 1 xiCP , i) i=1 2

∑ φi⎢⎢κS ,i +

(4)

where φi, κS,i, vi, αi, and CP,i are the volume fraction, isentropic compressibility, molar volume, thermal expansion coefficient,

Table 2. Comparison of Densities, ρ, Speeds of Sound, u, and Heat Capacities, CP, of Pure Liquids with Their Literature Values at T/K = 298.15, 303.15, and 308.15 and p = 0.1 MPaa ρ/kg·m−3

u/m·s−1

CP/(J·K−1·mol−1)

components

T/K

exptl

lit.

exptl

lit.

exptl

lit.

o-chlorotoluene

298.15

1077.3

1298.7

1299.06d

178.21

177.79f

303.15

1072.5

1076.44b 1077.40c 1072.60c

1280.7

180.01

179.59f

308.15

1067.6

181.71

181.29f

298.15

1058.9

1279.33d 1282.00e 1261.82e 1266.00f 1338.20i 1338.80k

122.14

121.56r 122.20k

303.15 308.15

1052.6 1046.3

298.15

1027.9

303.15

1022.3

308.15

1016.6

1,3-dioxolane

1,4-dioxane

tetrahydropyran

298.15

879.13

303.15

873.99

308.15

868.83

1262.7 1058.81g 1059.29h 1046.20i 1046.30j 1027.92i 1027.97k

1016.59i 1016.80j 879.16l 879.20m 873.95n 874.20m 868.80o 869.20m

1338.7 1316.8 1294.7

123.11 124.07

1346.0

1345.50k

152.74

152.77s

1324.4

1324.00p 1325.00q

153.89

154.02s

1302.5 1269.8

155.14 1269.30l 1270.00q

149.62

1246.8

151.22

1224.4

153.08

149.60t 149.80l

Standard uncertainties u are u(T) (DSA) = ± 0.01 K; u(ρ) = ± 0.5 kg·m−3; u(u) = ± 0.1 m·s−1, u(CP) = 0.3 %; u(T) (DSC) = ± 0.02 K. bReference 12. Reference 9. dReference 13. eReference 14. fReference 15. gReference 16. hReference 3. iReference 17. jReference 18. kReference 19. lReference 1. m Reference 20. nReference 21. oReference 22. pReference 23. qReference 24. rReference 29. sReference 30. tReference 31. a c

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Table 3. Measured Densities, ρ, Excess Molar Volumes, VE, Speeds of Sound, u, Isentropic Compressibilities, κS, and Excess Isentropic Compressibilities, κES , Data for the Studied Mixtures as a Function of Mole Fraction, x1, of Component (1) at T/K = 298.15, 303.15, and 308.15 and p = 0.1 MPaa ρ x1

0.0902 0.1536 0.2167 0.2734 0.3169 0.3843 0.4301 0.4831 0.5278 0.5834 0.6265 0.6793 0.7315 0.7829 0.8242 0.8565 0.9013 0.9325 0.0902 0.1536 0.2167 0.2734 0.3169 0.3843 0.4301 0.4831 0.5278 0.5834 0.6265 0.6793 0.7315 0.7829 0.8242 0.8565 0.9013 0.9325 0.0902 0.1536 0.2167 0.2734 0.3169 0.3843 0.4301 0.4831 0.5278 0.5834 0.6265 0.6793 0.7315 0.7829 0.8242 0.8565

kg·m

VE −3

κS

u −1

cm ·mol 3

o-Chlorotoluene (1) T/K = 1061.1 0.030 1062.6 0.045 1064.0 0.056 1065.2 0.063 1066.1 0.066 1067.5 0.069 1068.4 0.070 1069.4 0.068 1070.2 0.066 1071.2 0.062 1071.9 0.058 1072.7 0.052 1073.6 0.045 1074.4 0.038 1075.0 0.031 1075.4 0.026 1076.0 0.018 1076.5 0.013 T/K = 1054.9 0.039 1056.4 0.058 1057.9 0.072 1059.3 0.080 1060.2 0.084 1061.7 0.087 1062.7 0.087 1063.7 0.086 1064.6 0.083 1065.7 0.079 1066.5 0.074 1067.4 0.068 1068.3 0.060 1069.1 0.051 1069.8 0.043 1070.3 0.037 1071.0 0.026 1071.5 0.019 T/K = 1048.7 0.042 1050.4 0.064 1052.0 0.081 1053.4 0.092 1054.4 0.098 1055.9 0.104 1057.0 0.105 1058.1 0.104 1059.0 0.102 1060.2 0.097 1061.0 0.091 1062.0 0.083 1063.0 0.074 1063.9 0.063 1064.7 0.053 1065.2 0.044

−1

m·s

TPa

Table 3. continued x1 0.9013 0.9325

κES −1

+ 1,3-Dioxolane (2) 298.15 1326.8 535.4 1320.0 540.2 1314.3 544.1 1310.1 547.0 1307.4 548.8 1303.8 551.1 1301.9 552.2 1300.1 553.2 1298.9 553.9 1297.8 554.3 1297.3 554.4 1296.8 554.4 1296.6 554.0 1296.7 553.6 1296.9 553.1 1297.1 552.7 1297.5 552.1 1297.8 551.5 303.15 1304.4 557.2 1297.8 562.0 1292.5 565.8 1288.8 568.4 1286.4 570.0 1283.5 571.8 1281.9 572.7 1280.3 573.5 1279.3 573.9 1278.4 574.1 1277.9 574.2 1277.4 574.1 1277.3 573.8 1277.4 573.3 1277.6 572.7 1277.8 572.2 1278.5 571.3 1279.0 570.5 308.15 1281.7 580.5 1275.2 585.5 1270.4 589.0 1267.0 591.4 1265.1 592.6 1262.7 594.0 1261.4 594.6 1260.3 595.0 1259.6 595.2 1258.7 595.3 1258.3 595.3 1258.0 595.0 1257.8 594.6 1257.9 594.1 1258.1 593.4 1258.5 592.7

TPa−1 0.0984 0.1643 0.2124 0.2837 0.3427 0.3918 0.4375 0.4864 0.5237 0.5765 0.6237 0.6801 0.7135 0.7737 0.8125 0.8635 0.9012 0.9415

6.3 9.6 12.1 13.6 14.4 15.2 15.2 15.0 14.6 13.7 12.8 11.5 10.0 8.4 6.9 5.8 4.1 2.8

0.0984 0.1643 0.2124 0.2837 0.3427 0.3918 0.4375 0.4864 0.5237 0.5765 0.6237 0.6801 0.7135 0.7737 0.8125 0.8635 0.9012 0.9415

7.4 10.9 13.4 14.8 15.6 16.0 15.9 15.6 15.1 14.2 13.4 12.2 10.8 9.2 7.8 6.7 4.8 3.4

0.0984 0.1643 0.2124 0.2837 0.3427 0.3918 0.4375 0.4864 0.5237 0.5765 0.6237 0.6801 0.7135 0.7737 0.8125 0.8635 0.9012 0.9415

8.7 12.6 15.1 16.5 17.0 17.2 17.0 16.5 15.9 15.1 14.3 13.1 11.8 10.3 9.0 7.8 686

ρ

VE

u

κS

κES

kg·m−3

cm3·mol−1

m·s−1

TPa−1

TPa−1

T/K = 308.15 1066.0 0.032 1259.3 591.5 1066.5 0.022 1260.1 590.5 o-Chlorotoluene (1) + 1,4-Dioxane (2) T/K = 298.15 1033.4 0.087 1338.2 540.4 1036.9 0.131 1333.2 542.6 1039.5 0.157 1329.9 544.0 1043.3 0.186 1325.3 545.7 1046.3 0.202 1321.8 547.0 1048.9 0.210 1319.1 547.9 1051.2 0.213 1316.8 548.6 1053.6 0.212 1314.5 549.3 1055.5 0.208 1312.8 549.7 1058.1 0.200 1310.7 550.2 1060.4 0.188 1308.8 550.5 1063.0 0.170 1306.9 550.8 1064.6 0.157 1305.8 550.9 1067.4 0.131 1304.0 551.0 1069.2 0.112 1302.9 551.0 1071.4 0.084 1301.7 550.9 1073.1 0.062 1300.8 550.8 1074.9 0.038 1299.9 550.6 T/K = 303.15 1027.7 0.097 1316.6 561.4 1031.3 0.144 1312.0 563.3 1033.9 0.170 1308.9 564.6 1037.8 0.197 1304.6 566.2 1040.9 0.210 1301.5 567.2 1043.5 0.216 1299.0 567.9 1045.9 0.218 1296.9 568.5 1048.4 0.216 1294.8 569.0 1050.3 0.212 1293.2 569.3 1052.9 0.202 1291.2 569.7 1055.2 0.191 1289.6 569.9 1057.9 0.174 1287.7 570.0 1059.5 0.162 1286.7 570.1 1062.3 0.137 1285.0 570.0 1064.1 0.118 1284.1 569.9 1066.4 0.091 1283.0 569.7 1068.1 0.068 1282.2 569.5 1069.9 0.042 1281.5 569.1 T/K = 308.15 1022.0 0.111 1295.1 583.4 1025.6 0.159 1290.8 585.2 1028.3 0.184 1287.9 586.3 1032.3 0.208 1284.0 587.6 1035.5 0.218 1281.2 588.4 1038.2 0.223 1279.0 588.9 1040.6 0.222 1277.0 589.3 1043.1 0.219 1275.1 589.6 1045.1 0.215 1273.8 589.8 1047.7 0.206 1271.9 590.0 1050.1 0.196 1270.4 590.1 1052.8 0.180 1268.7 590.1 1054.4 0.169 1267.8 590.1 1057.2 0.146 1266.3 589.9 1059.0 0.129 1265.4 589.7 1061.4 0.102 1264.4 589.3 1063.1 0.079 1263.8 589.0 1064.9 0.050 1263.3 588.5

5.8 4.2

2.4 3.6 4.3 5.2 5.6 5.9 6.0 5.9 5.9 5.6 5.3 4.8 4.5 3.7 3.2 2.4 1.8 1.1 2.6 3.9 4.6 5.4 5.8 6.0 6.1 6.1 6.0 5.8 5.5 5.0 4.7 4.0 3.5 2.7 2.0 1.3 2.9 4.3 4.9 5.7 6.0 6.1 6.2 6.1 6.0 5.8 5.5 5.1 4.8 4.2 3.7 2.9 2.3 1.4



Article

Table 3. continued x1

0.1156 0.1765 0.2342 0.2765 0.3305 0.3716 0.4235 0.4721 0.5216 0.5803 0.6317 0.6796 0.7216 0.7737 0.8219 0.8753 0.9064 0.9325 0.1156 0.1765 0.2342 0.2765 0.3305 0.3716 0.4235 0.4721 0.5216 0.5803 0.6317 0.6796 0.7216 0.7737 0.8219 0.8753 0.9064 0.9325 0.1156 0.1765 0.2342 0.2765 0.3305 0.3716 0.4235 0.4721 0.5216 0.5803 0.6317 0.6796 0.7216 0.7737 0.8219 0.8753 0.9064 0.9325

ρ

V

kg·m−3

cm3·mol−1

E

u

κS

κES

m·s−1

TPa−1

TPa−1

o-Chlorotoluene (1) + Tetrahydropyran T/K = 298.15 906.77 −0.086 1274.6 920.75 −0.120 1277.0 933.65 −0.146 1279.3 942.89 −0.160 1280.9 954.43 −0.175 1282.9 963.04 −0.183 1284.4 973.69 −0.188 1286.2 983.44 −0.189 1287.9 993.16 −0.187 1289.4 1004.4 −0.179 1291.2 1014.1 −0.169 1292.6 1022.8 −0.156 1293.9 1030.4 −0.142 1294.8 1039.6 −0.122 1296.0 1047.9 −0.101 1296.8 1057.0 −0.074 1297.7 1062.2 −0.057 1298.1 1066.5 −0.042 1298.3 T/K = 303.15 901.67 −0.092 1252.7 915.67 −0.127 1255.6 928.57 −0.152 1258.1 937.81 −0.167 1259.9 949.36 −0.180 1262.0 957.97 −0.188 1263.7 968.63 −0.193 1265.7 978.39 −0.193 1267.4 988.12 −0.191 1269.0 999.40 −0.184 1271.1 1009.1 −0.173 1272.7 1017.9 −0.160 1274.1 1025.4 −0.147 1275.3 1034.7 −0.127 1276.7 1043.0 −0.106 1277.8 1052.1 −0.079 1279.0 1057.3 −0.061 1279.5 1061.6 −0.046 1279.9 T/K = 308.15 896.57 −0.098 1230.7 910.57 −0.134 1233.7 923.48 −0.160 1236.6 932.73 −0.174 1238.6 944.29 −0.188 1241.0 952.90 −0.194 1242.9 963.56 −0.198 1245.0 973.33 −0.199 1247.0 983.08 −0.197 1249.0 994.39 −0.190 1251.1 1004.1 −0.180 1252.8 1012.9 −0.168 1254.5 1020.5 −0.154 1255.7 1029.7 −0.135 1257.3 1038.1 −0.114 1258.6 1047.2 −0.085 1260.0 1052.4 −0.067 1260.7 1056.7 −0.050 1261.4

Table 4. Measured Heat Capacities, (CP)12, and Excess Heat Capacity, CEP, Data for the Various Binary Mixtures as a Function of Mole Fraction, x1, of Component (1) at T/K = 298.15, 303.15, and 308.15 and p = 0.1 MPaa

(2) 678.8 666.0 654.5 646.4 636.6 629.4 620.8 613.1 605.7 597.2 590.2 584.0 578.9 572.7 567.4 561.8 558.8 556.3

−8.7 −12.1 −14.7 −16.2 −17.6 −18.4 −19.0 −19.1 −18.9 −18.3 −17.2 −16.0 −14.6 −12.7 −10.5 −7.8 −6.1 −4.5

706.7 692.8 680.4 671.7 661.3 653.7 644.5 636.3 628.4 619.3 611.9 605.2 599.6 593.0 587.2 581.1 577.8 575.0

−10.0 −13.7 −16.4 −18.0 −19.3 −20.1 −20.6 −20.6 −20.2 −19.5 −18.4 −17.0 −15.5 −13.5 −11.1 −8.3 −6.4 −4.8

736.5 721.5 708.1 698.8 687.6 679.4 669.5 660.7 652.1 642.5 634.5 627.4 621.5 614.3 608.1 601.5 597.8 594.8

−10.4 −14.4 −17.4 −19.1 −20.5 −21.4 −21.8 −22.0 −21.6 −20.6 −19.3 −17.9 −16.2 −14.0 −11.5 −8.4 −6.5 −4.8

x1

0.0865 0.1145 0.1386 0.1829 0.2145 0.2573 0.2965 0.3217 0.3506 0.3902 0.4216 0.4654 0.0865 0.1145 0.1386 0.1829 0.2145 0.2573 0.2965 0.3217 0.3506 0.3902 0.4216 0.4654 0.0865 0.1145 0.1386 0.1829 0.2145 0.2573 0.2965 0.3217 0.3506 0.3902 0.4216 0.4654

0.0903 0.1278 0.1654 0.2006 0.2343 0.2765 0.3004 0.3421 0.3876 0.4002 0.4327 0.4726

Standard uncertainties u are u(T) = ± 0.01 K; u(x1) = ± 1·10−4; u (ρ) = ± 0.5 kg·m−3; u(u) = ± 0.1 m·s−1, u(VE) = 0.1 %; u (κES ) = 0.2 %.

a

0.0903 0.1278 687

(CP)12

CEP

J·K−1·mol−1

J·K−1·mol−1

x1

(CP)12

CEP

J·K−1·mol−1

J·K−1·mol−1

o-Chlorotoluene (1) + 1,3-Dioxolane (2) T/K = 298.15 127.97 0.98 0.5007 153.78 129.85 1.29 0.5418 156.06 131.45 1.54 0.5905 158.68 134.37 1.97 0.6218 160.32 136.42 2.26 0.6630 162.44 139.17 2.61 0.6902 163.81 141.65 2.88 0.7118 164.88 143.22 3.04 0.7534 166.91 144.99 3.19 0.7927 168.78 147.38 3.36 0.8426 171.11 149.24 3.46 0.8914 173.35 151.78 3.55 0.9206 174.66 T/K = 303.15 129.15 1.12 0.5007 155.35 131.07 1.44 0.5418 157.66 132.71 1.71 0.5905 160.33 135.68 2.16 0.6218 162.01 137.77 2.46 0.6630 164.17 140.56 2.81 0.6902 165.56 143.06 3.08 0.7118 166.65 144.65 3.24 0.7534 168.72 146.45 3.39 0.7927 170.62 148.87 3.55 0.8426 172.98 150.75 3.65 0.8914 175.22 153.32 3.73 0.9206 176.53 T/K = 308.15 130.30 1.25 0.5007 156.88 132.27 1.60 0.5418 159.23 133.94 1.88 0.5905 161.94 136.97 2.36 0.6218 163.64 139.09 2.66 0.6630 165.83 141.91 3.01 0.6902 167.25 144.45 3.29 0.7118 168.36 146.05 3.44 0.7534 170.46 147.87 3.59 0.7927 172.38 150.31 3.75 0.8426 174.76 152.22 3.85 0.8914 177.00 154.82 3.93 0.9206 178.31 o-Chlorotoluene (1) + 1,4-Dioxane (2) T/K = 298.15 155.43 0.39 0.5117 167.43 156.54 0.54 0.5401 168.17 157.65 0.70 0.5915 169.49 158.69 0.84 0.6305 170.45 159.68 0.97 0.6721 171.46 160.90 1.12 0.7198 172.57 161.59 1.20 0.7401 173.03 162.78 1.33 0.7623 173.53 164.06 1.45 0.8004 174.36 164.41 1.48 0.8432 175.26 165.31 1.55 0.8856 176.11 166.39 1.61 0.9165 176.70 T/K = 303.15 156.69 0.44 0.5117 168.97 157.84 0.61 0.5401 169.73

3.57 3.54 3.43 3.32 3.13 2.97 2.83 2.53 2.20 1.73 1.22 0.91 3.75 3.73 3.62 3.52 3.33 3.18 3.04 2.74 2.41 1.92 1.39 1.04 3.95 3.93 3.83 3.73 3.55 3.40 3.26 2.96 2.62 2.12 1.55 1.17

1.66 1.68 1.68 1.66 1.60 1.50 1.44 1.38 1.23 1.04 0.81 0.62 1.71 1.74



Article

Table 4. continued x1 0.1654 0.2006 0.2343 0.2765 0.3004 0.3421 0.3876 0.4002 0.4327 0.4726 0.0903 0.1278 0.1654 0.2006 0.2343 0.2765 0.3004 0.3421 0.3876 0.4002 0.4327 0.4726

0.0897 0.1165 0.1429 0.1929 0.2376 0.2892 0.3218 0.3519 0.4019 0.4427 0.4817 0.5216 0.0897 0.1165 0.1429 0.1929 0.2376 0.2892 0.3218 0.3519 0.4019 0.4427 0.4817 0.5216 0.0897 0.1165 0.1429 0.1929 0.2376 0.2892 0.3218 0.3519

Table 4. continued

(CP)12

CEP

J·K−1·mol−1

J·K−1·mol−1

x1

(CP)12

CEP

J·K−1·mol−1

J·K−1·mol−1 1.75 1.73 1.68 1.59 1.54 1.47 1.33 1.14 0.90 0.69

T/K = 303.15 0.77 0.5915 171.09 0.91 0.6305 172.09 1.04 0.6721 173.13 1.19 0.7198 174.28 1.26 0.7401 174.76 1.39 0.7623 175.27 1.50 0.8004 176.13 1.53 0.8432 177.05 1.60 0.8856 177.92 1.67 0.9165 178.52 T/K = 308.15 158.03 0.49 0.5117 170.50 159.20 0.66 0.5401 171.28 160.36 0.83 0.5915 172.67 161.44 0.97 0.6305 173.70 162.46 1.09 0.6721 174.77 163.73 1.24 0.7198 175.95 164.44 1.31 0.7401 176.44 165.66 1.44 0.7623 176.97 166.99 1.55 0.8004 177.84 167.35 1.58 0.8432 178.78 168.28 1.65 0.8856 179.66 169.41 1.72 0.9165 180.26 o-Chlorotoluene (1) + Tetrahydropyran (2) T/K = 298.15 152.82 0.63 0.5549 168.00 153.77 0.82 0.5936 169.07 154.71 1.00 0.6215 169.81 156.46 1.33 0.6518 170.60 158.01 1.60 0.6902 171.57 159.77 1.88 0.7205 172.31 160.85 2.03 0.7515 173.04 161.84 2.16 0.7931 173.99 163.44 2.33 0.8156 174.49 164.71 2.43 0.8472 175.18 165.88 2.49 0.8831 175.93 167.05 2.52 0.9146 176.56 T/K = 303.15 154.40 0.59 0.5549 169.62 155.35 0.77 0.5936 170.69 156.28 0.95 0.6215 171.44 158.04 1.27 0.6518 172.23 159.59 1.53 0.6902 173.21 161.35 1.80 0.7205 173.96 162.44 1.95 0.7515 174.70 163.43 2.08 0.7931 175.66 165.03 2.24 0.8156 176.17 166.31 2.34 0.8472 176.87 167.49 2.40 0.8831 177.63 168.66 2.43 0.9146 178.29 T/K = 308.15 156.20 0.56 0.5549 171.30 157.14 0.73 0.5936 172.36 158.07 0.89 0.6215 173.11 159.80 1.20 0.6518 173.90 161.34 1.46 0.6902 174.87 163.09 1.73 0.7205 175.62 164.17 1.87 0.7515 176.36 165.15 2.00 0.7931 177.32 158.98 160.04 161.05 162.30 163.00 164.21 165.52 165.87 166.79 167.90

(CP)12

CEP

x1

J·K−1·mol−1

J·K−1·mol−1

0.4019 0.4427 0.4817 0.5216

166.75 168.01 169.19 170.35

x1

T/K = 308.15 2.16 0.8156 2.26 0.8472 2.32 0.8831 2.34 0.9146

(CP)12

CEP

J·K−1·mol−1

J·K−1·mol−1

177.83 178.52 179.30 179.96

1.40 1.19 0.93 0.70

a Standard uncertainties u are u(x1) = ± 1·10−4, u(T) = ± 0.02 K, and u(CEP) = 0.3 %.

1.77 1.79 1.82 1.81 1.77 1.69 1.64 1.57 1.44 1.24 0.99 0.77

Figure 1. Excess molar volumes, VE, at 298.15 K for (I) o-chlorotoluene (1) + 1, 3-dioxolane (2): ▲, expt.; , graph; ---, PFP; (II) o-chlorotoluene (1) + 1,4-dioxane (2): ●, expt.; , graph; ---, PFP; (III) o-chlorotoluene (1) + tetrahydropyran (2): ■, expt.; , graph; ---, PFP.

2.51 2.47 2.42 2.35 2.22 2.09 1.94 1.70 1.56 1.33 1.06 0.80 2.42 2.38 2.33 2.25 2.12 1.99 1.84 1.61 1.47 1.26 0.99 0.74

Figure 2. Excess isentropic compressibilities, κES , at 298.15 K for (I) o-chlorotoluene (1) + 1,3-dioxolane (2): ▲, expt.; , graph; ---, PFP; (II) o-chlorotoluene (1) + 1,4-dioxane (2): ●, expt.; , graph; ---, PFP; (III) o-chlorotoluene (1) + tetrahydropyran (2): ■, expt.; , graph; ---, PFP.

2.33 2.29 2.24 2.16 2.03 1.91 1.76 1.53

and molar heat capacity respectively of the pure component (i). The α values for pure liquids were calculated from the measured density data in the manner described elsewhere.33 The VE, κES , HE, and CEP values of the investigated mixtures are recorded in Table 3, Supplementary Table S1, and Table 4, respectively, and represented in Figures 1 to 4, respectively. 688



Article

Table 5. Binary Adjustable Parameters, Xn (X = V or H or κS or CP; n = 0 to 2) of eq 5 along with Their Standard Deviations, σ(XE) (X = V or κS or H or CP) of VE, κES , HE, and CEP at T/K = 298.15, 303.15, and 308.15 T/K parameter

Figure 4. Excess heat capacities, CEP, at 298.15 K for (I) o-chlorotoluene (1) + 1,3-dioxolane (2): ▲, expt.; , graph; ---, PFP; (II) o-chlorotoluene (1) + 1,4-dioxane (2): ●, expt.; , graph; ---, PFP; (III) o-chlorotoluene (1) + tetrahydropyran (2): ■, expt.; , graph; ---, PFP.

The VE, κES , HE, and CEP data for each mixture were fitted to eq34 X E(X = V or κS or H or CP) = x1x 2[X (0) + X (1)(2x1 − 1) (5)

(n)

where X (n = 0 to 2) etc. are the binary parameters and determined by least-squares optimizations. These parameters together with standard deviations, σ(XE) (X = V or κS or H or CP), defined by m E E σ(X E) = [ ∑ (Xexptl − Xcalc.eq5 )2 /(m − n)]0.5 1

303.15

o-Chlorotoluene (1) + 1,3-Dioxolane (2) V(0) 0.269 0.340 V(1) −0.095 −0.107 V(2) 0.020 0.065 σ(VE)/cm3·mol −1 0.001 0.001 κ(0) 59.4 61.8 S κ(1) −19.2 −21.6 S κ(2) 2.2 15.1 S σ(κES )/TPa−1 0.1 0.1 H(0) H(1) H(2) σ(HE)/J·mol−1 C(0) 14.27 15.01 P C(1) 0.01 0.08 P C(2) −2.65 −1.19 P σ(CEP)/J·K−1·mol−1 0.01 0.01 o-Chlorotoluene (1) + 1,4-Dioxane (2) V(0) 0.843 0.858 V(1) −0.171 −0.204 V(2) −0.009 0.115 σ(VE)/cm3·mol−1 0.001 0.001 κ(0) 23.7 24.1 S κ(1) −4.1 −4.2 S κ(2) −0.5 3.1 S σ(κES )/TPa−1 0.1 0.1 H(0) H(1) H(2) σ(HE)/J·mol−1 C(0) 6.58 6.81 P C(1) 2.07 2.20 P C(2) −0.29 0.57 P σ(CEP)/J·K−1·mol−1 0.01 0.01 o-Chlorotoluene (1) + Tetrahydropyran (2) V(0) −0.753 −0.770 V(1) 0.106 0.114 V(2) −0.005 −0.066 σ(VE)/cm3·mol −1 0.001 0.001 κ(0) −76.0 −81.9 S κ(1) 8.6 13.9 S κ(2) −3.3 −8.0 S σ(κES )/TPa−1 0.1 0.1 H(0) H(1) H(2) σ(HE)/J·mol−1 C(0) 10.03 9.67 P C(1) 1.48 1.35 P C(2) −1.57 −1.90 P σ(CEP)/J·K−1·mol−1 0.01 0.01

Figure 3. Excess molar enthalpies, HE, at 308.15 K for (I) o-chlorotoluene (1) + 1,3-dioxolane (2): ▲, expt.; , graph; ---, PFP; (II) o-chlorotoluene (1) + 1,4-dioxane (2): ●, expt.; , graph; ---, PFP; (III) o-chlorotoluene (1) + tetrahydropyran (2): ■, expt.; , graph; ---, PFP.

+ X (2)(2x1 − 1)2 ]

298.15

(6)

308.15 0.414 −0.098 0.031 0.001 65.2 −25.0 30.7 0.1 1580 −341 −111 2 15.80 0.17 0.18 0.01 0.870 −0.224 0.300 0.001 24.3 −4.8 7.4 0.1 1429 −564 −98 2 7.02 2.46 1.37 0.01 −0.792 0.114 −0.138 0.001 −87.1 16.0 −4.2 0.1 −875 −89 34 2 9.32 1.28 −2.15 0.01

4. DISCUSSION The VE, κES , HE, and CEP data of the studied mixtures are not available in the literature. The VE, κES , and HE values of o-CT (1) + D or D/(2) mixtures are positive, and those for

where m and n are the number of data points and number of adjustable parameters, respectively. XE(calc.eq 5) are the values determined by employing eq 5 and are presented in Table 5. 689



Article

Table 6. Comparison of Calculated VE, κES , and CEP at T/K = 298.15, 303.15, and 308.15 and HE at T/K = 308.15 Values from Appropriate Equations with Their Corresponding Experimental Values mole fraction of component property

0.1

0.2

VE(expt.)/cm3·mol−1 VE(graph)/cm3·mol−1 κES (expt.)/TPa−1 κES (graph)/TPa−1 CEP(expt.)/J·K−1·mol−1 CEP(graph)/J·K−1·mol−1

0.032 0.031 6.4 7.2 1.12 1.35

0.055 0.052 11.8 12.1 2.14 2.37


0.042 0.040 7.7 7.6 1.27 1.39

0.068 0.066 13.0 12.8 2.33 2.46

VE(expt.)/cm3·mol−1 VE(graph)/cm3·mol−1 κES (expt.)/TPa−1 κES (graph)/TPa−1 CEP(expt.)/J·K−1·mol−1 CEP(graph)/J·K−1·mol−1 HE(expt.)/J·mol−1 HE(graph)/J·mol−1

0.045 0.048 9.4 7.8 1.42 1.46 161 161

0.078 0.079 14.5 13.1 2.50 2.58 278 280


0.088 0.089 2.3 2.5 0.44 0.47

0.153 0.151 4.3 4.3 0.82 0.88


0.100 0.091 2.7 2.6 0.50 0.47

0.163 0.155 4.4 4.5 0.89 0.90


0.116 0.093 3.0 2.7 0.54 0.49 164 164

0.170 0.158 4.6 4.6 0.95 0.93 276 277


−0.075 −0.074 −7.8 −7.3 0.72 0.75

−0.134 −0.128 −12.9 −12.8 1.37 1.40

0.3

0.4

0.5

o-Chlorotoluene (1) + 1,3-Dioxolane (2) T/K = 298.15 0.066 0.070 0.068 0.064 0.069 15.5 15.7 14.4 14.9 14.9 2.88 3.47 3.62 3.07 3.57 T/K = 303.15 0.083 0.090 0.086 0.082 0.088 16.4 16.6 15.2 15.7 15.7 3.09 3.63 3.80 3.20 3.75 T/K = 308.15 0.099 0.109 0.103 0.097 0.104 17.2 17.4 16.5 16.3 16.8 3.33 3.82 3.98 3.37 3.95 356 394 395 356 394 o-Chlorotoluene (1) + 1,4-Dioxane (2) T/K = 298.15 0.188 0.208 0.208 0.189 0.208 5.3 6.0 6.0 5.5 5.9 1.15 1.49 1.68 1.23 1.65 T/K = 303.15 0.198 0.212 0.214 0.195 0.214 5.5 6.2 6.2 5.6 6.1 1.22 1.54 1.74 1.26 1.71 T/K = 308.15 0.207 0.215 0.218 0.198 0.218 5.7 6.4 6.3 5.8 6.3 1.29 1.59 1.80 1.30 1.77 344 370 357 344 358 o-Chlorotoluene (1) + THP (2) T/K = 298.15 −0.164 −0.183 −0.189 −0.165 −0.185 −16.5 −18.7 −19.2 −16.6 −19.3 1.90 2.28 2.50 1.90 2.48 690

0.6

0.7

0.059 0.061 12.7

0.048 0.051 10.2 9.6 2.85 2.90

0.035 0.037 7.6 5.9 2.09 2.16

0.019 0.020 4.4 2.5 1.16 1.19

0.063 0.065 11.1 10.0 3.10 3.08

0.047 0.047 8.3 6.2 2.30 2.31

0.028 0.025 5.3 2.6 1.31 1.28

0.077 0.078 12.4 11.3 3.35 3.25 300 300

0.057 0.056 9.3 7.4 2.52 2.44 216 214

0.034 0.030 6.1 3.3 1.46 1.35 111 111

0.166 0.162 4.5 4.4 1.57 1.58

0.118 0.119 3.5 3.1 1.20 1.28

0.062 0.065 1.8 1.6 0.73 0.77

0.170 0.167 4.7 4.5 1.65 1.65

0.124 0.122 3.7 3.2 1.30 1.35

0.068 0.067 2.1 1.7 0.81 0.81

0.178 0.170 4.8 4.6 1.72 1.71 250 250

0.134 0.125 3.7 3.3 1.40 1.39 168 168

0.078 0.068 2.4 1.7 0.90 0.84 82.4 81.0

−0.152 −0.153 −15.3 −15.7 2.24 2.26

−0.110 −0.115 −11.4 −11.8 1.67 1.80

−0.060 −0.063 −6.4 −6.5 0.90 1.05

3.37

0.076 0.079 13.4 3.56

0.093 0.093 14.6 3.75 362

0.198 0.192 5.3 1.69

0.203 0.198 5.5 1.76

0.209 0.202 5.7 1.82 316

−0.177 −0.178 −18.2 2.48

0.8

0.9



Article

Table 6. continued mole fraction of component property

0.1

0.2

0.3


−0.080 −0.075 −9.0 −8.1 0.67 0.74

−0.141 −0.130 −14.6 −14.2 1.31 1.37

−0.173 −0.168 −18.3 −18.2 1.85 1.86


−0.086 −0.076 −9.2 −9.1 0.62 0.73 −70.5 −72.1

−0.150 −0.133 −15.7 −15.6 1.26 1.33 −131 −131

−0.181 −0.171 −19.6 −19.8 1.79 1.80 −172 −176

0.4

0.5

T/K = 303.15 −0.190 −0.188 −20.3

−0.192 −20.8 −20.7 2.40 2.37

2.20 T/K = 308.15 −0.193 −0.192 −21.8

−0.196 −22.0 −21.9 2.30 2.28 −220 −219

2.12 −205

o-CT(1) + THP (2) mixtures are negative over entire mole fraction. While κES and HE data at equimolar composition vary in the order: D > D/ > THP; VE values follow the order: D/ > D > THP. Further CEP values for the studied mixtures are positive over entire composition range and for an equimolar composition vary as D > THP > D/. The HE values of (1 + 2) mixtures can be explained by assuming that (i) o-CT (1) is an associated molecular entity and D, D/, and THP (2) are characterized by dipole−dipole interactions; (ii) the formation of unlike contacts weakens 1−1 and 2−2 interactions to form their respective monomers; and (iii) monomers of (1) and (2) undergo interactions to form a 1:1 molecular complex. The HE data for these mixtures suggest that the contribution to HE due to factor (ii) far outweigh the contribution due to factors (i) and (iii), so that overall HE values for the mixtures are positive. The HE values for o-CT (1) + THP (2) mixtures are lesser than those of o-CT (1) + D or D/ (2) mixtures. This may be due to a higher dipole moment of THP (1.63D)10 which in turn yields strong interactions among the components of the (1 + 2) mixture. The HE values of o-CT (1) + D (2) mixtures are higher than those of o-CT (1) + D/ (2) in spite of higher dipole moment of D (1.47D)10 as compared to D/ (0.45D).10 This may be due to larger cyclic ring of D/ which in turn resists the approach of D/ molecules toward o-CT as compared to D. The VE and κES values of the investigated mixtures suggest that THP gives relatively more packed arrangement in o-CT as compared to D or D/. The magnitude and sign of CEP values is the cumulative effect of contributions, namely, (i) disruption of associated entities to give more random structure and (ii) formation of complexity among constituent molecules to yield nonrandom structure. The positive CEP values for (1 + 2) mixtures suggest that the contribution to CEP due to complexity far outweighs the contribution due to more random structures. The VE, κES , and HE data of (1 + 2) mixtures were analyzed in terms of graph as well as PFP theories. The CEP data of the investigated mixtures have also been estimated by employing graph theory.

0.6

0.7

0.8

0.9

−0.178 −0.181 −19.3

−0.158 −0.155 −16.3 −16.4 2.14 2.14

−0.115 −0.116 −12.2 −12.2 1.59 1.69

−0.065 −0.064 −6.8 −6.6 0.84 0.98

−0.160 −0.159 −17.1 −16.9 2.05 2.03 −192 −192

−0.124 −0.119 −12.3 −12.2 1.52 1.59 −145 −150

−0.071 −0.066 −7.0 −6.5 0.79 0.92 −83.5 −86.3

2.36

−0.190 −0.185 −20.2 2.25 −215

the constituent molecules which in turn changes with the addition of 1 to 2 or vice versa. The excess molar volumes, VE, is a packing effect and reflects change in the topologies of 1 or 2 in the mixed state; it was, therefore, considered to analyze the VE data of the present mixtures in terms of graph theory to obtain information about the state of components in pure and mixed states. According to graph theory,35 excess molar volumes, VE, are given by ⎡ x1 x2 ⎤ 1 ⎥ V E = α12⎢ 3 − − 3 3 ξ1 ξ2 ⎦ ⎣ x1( ξ1)m + x 2(3ξ 2)m

(7)

where x1 is the mole fraction of the component 1 and α12 is a constant characteristic of the (1 + 2) mixture. The (3ξ1) (1 = 1 or 2) and (3ξ1) m (1 = 1 or 2) are connectivity parameters of th ethird degree of a molecule and defined36 by 3

∑

ξ=

(δmνδnνδoνδpν)−0.5 (8)

m

Densities, Speeds of Sound, Excess Molar Enthalpies, and Heat

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