Fluid Phase Equilibria, 60 (1990) 205-212 Elsevier Science Publishers B.V., Amsterdam

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TOTAL VAPOUR PRESSURES FOR BINARY LIQUID MIXTURES OF ACETONE WITH TETRACHLOROETHYLENE, TRICHLOROETHYLENE, METHYLENE CHLORIDE, 1,2-DICHLOROETHANE AND CYCLOHEXANE AT 273.15 K

JAGAN NATH * and ATMA PRAKASH DIXIT

Chew&v Department, Gorakhpur University, Gorakhpur-273009 (India)

(Received November 21,1988; accepted in final form April 26, 1990)

ABSTRACT

Nath, J. and Dixit, A.P., 1990. Total vapour pressures for binary liquid mixtures of acetone with tetrachloroethylene, trichloroethylene, methylene chloride, 1,Zdichloroethane and cyclohexane at 273.15 K. Fluid Phase Equilibria, 60: 205-212.

Total vapour pressures, P, have been measured for binary liquid mixtures of acetone with tetrachloroethylene (CCl,CC12), trichloroethylene (CHC1CC12), methylene chloride (CH2 Cl,), 1,Zdichloroethane (CH,ClCH,Cl) and cyclohexane (c-C,H,,) at 273.15 K, using a static method. The values of P have been used to calculate the values of the activity coefficients of the two components in the various systems and those of the excess Gibbs free energies, gE, for the various mixtures, using Barker’s method. The values of gE are monotonic in each mixture: in order of relative magnitude they are positive for c-C,H,,, CCl,CCl, and CHClCCl,, and negative for CH,Cl, and CH,ClCH,Cl. The results indicate the existence of a specific interaction between acetone and CR&l,, CH,CICH,Cl, CHClCCl, and CCl,CCl, in the liquid state.

INTRODUCTION

Binary systems of acetone with tetrachloroethylene (CCl,CCl,), trichloro- ethylene (CHClCCl,), methylene chloride (CH,Cl,), 1,2-dichloroethane (CH,ClCH,Cl) and cyclohexane (c-C,H,,) are of considerable interest from the viewpoint of the existence of specific interaction between the compo- nents. Recently, (Nath and Dixit, 1984a) measurements of excess volumes, ultrasonic velocities and adiabatic compressibilities for the systems acetone + CCl,CCl,, acetone + CHClCCl,, acetone + CH,C12, acetone + CH,Cl- CH,Cl and acetone + C-C,H,, have been made at different temperatures.

* To whom correspondence should be addressed.

0378-3812/90/$03.50 0 1990 - Elsevier Science Publishers B.V.

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Further measurements of viscosities (Nath and Dixit, 1984b), and dielectric constants and refractive indices (Nath and Dixit, 1985) for these systems have also been made at 303.15 K. These studies have indicated the existence of a specific interaction between acetone and CH,Cl,, CH,ClCH,Cl, CHCl- Ccl, and CCl,CCl, in the liquid state. In order to obtain conclusive evidence about the existence of these specific interactions we have made measurements of total vapour pressures for binary liquid mixtures of acetone with these chloro compounds and with c-C,H,, at 273.15 K, as the specific interactions between the components are expected to be predominant at lower temperatures, and the results of these measurements are interpreted in this paper. Isobaric vapour-liquid equilibrium studies for binary systems of acetone with c-C,H,,, CHClCCl,, CCl,CCl,, CH,ClCH,Cl and CH,Cl, at 760 torr have been made by various workers: acetone with cyclohexane (Kurmanadharao and Rao, 1957) trichloroethylene (Acharya and Rao, 1953) tetrachloroethylene (Dakshinamurty and Rao, 1955) 1,2-dichloro- ethane (Fordyce and Simonsen, 1949) and methylene chloride (Iino et al., 1971).

EXPERIMENTAL

Methylene chloride (E. Merck) of spectral grade was placed over anhydrous calcium chloride to remove any traces of moisture and then subjected to fractional distillations. 1,2_Dichloroethane (B.D.H.) was washed with an aqueous solution of sodium bicarbonate, dried over anhydrous calcium chloride and then fractionally distilled over phosphorus pentoxide. Trichloroethylene (S. Merck) of electronic grade and tetrachloroethylene (E. Merck) of spectral grade were placed over anhydrous calcium chloride overnight and then distilled. Cyclohexane (B.D.H.) of reagent grade was purified by following the procedure described by Adcock and McGlashan (1954). Acetone (Rechem) of electronic grade was fractionally distilled over phosphorus pentoxide. The purities of the various components were checked by measurements of densities, which were found to be in good agreement with the available data (Timmermans, 1950; Riddick and Bunger, 1970).

The total vapour pressures were measured at 273.15 + 0.01 K by placing each of the prepared mixtures in a small bulb (capacity about 20 cm3) which was attached to one limb of a mercury U-tube manometer through a high-vacuum three-way stopcock and a glass side tube. The two upper ends of the manometer were connected to a vacuum system through high-vacuum stopcocks. The liquid sample in the bulb was then frozen to low tempera- tures by surrounding the bulb with liquid nitrogen, and the bulb and the manometer assembly were then completely evacuated. The bulb containing the sample whose vapour pressure was to be measured was disconnected

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from the manometer. The two limbs of the manometer were further evacuated and then disconnected from the vacuum system by closing the stopcocks attached to the two upper ends of the manometer, while ensuring that the mercury in the limbs of the manometer stood at the same level. The bulb containing the sample was then placed in melting ice at 273.15 + 0.01 K contained in an evacuated jacket, and it was then connected to the manome- ter by opening the stopcock. When equilibrium had been attained, the heights of the mercury levels in the two limbs of the manometer were noted using a cathetometer accurate to +O.Ol mm. The measured values of the vapour pressures were corrected for standard gravity: this was of the order of 0.2%. The uncertainty in the mole fractions of the components is of the order of f 0.0005.

RESULTS AND DISCUSSION

The values of the vapour pressures of the various pure liquids at 273.15 K determined here are compared with the literature values in Table 1; there is good agreement between the two sets of values. The experimental values of the total vapour pressures, P, for the various liquid mixtures of acetone at 273.15 K are given in Table 2. The experimental values of P for the systems acetone + CH,Cl, and acetone + CHClCCl, have been plotted against mole fraction, x1, of acetone in Fig. 1, and those for acetone + c-C,H,,, acetone + CH,ClCH,Cl and acetone + CCl,CCl, have been plotted against x1 in Fig. 2. The total vapour pressure/composition data have been used to calculate the values of the activity coefficients of the components of the various systems and those of excess Gibbs free energies, gE, for acetone + CH,Cl,, acetone + CH,ClCH,Cl, acetone + CHClCCl,, acetone + CCl,CCl, and acetone + c-C~H~~, by following Barker’s method (Barker,

TABLE I

Values of vapour pressures, P, for the various pure liquids at 273.15 K

Liquid P (torr)

This work Literature values

Acetone Methylene chloride 1,2-Dichloroethane Trichloroethylene Tetrachloroethylene Cyclohexane

a Reid et al. (1977). b Ha et al. (1976).

70.30 70.51 a 145.25 144.38 a 21.05 21.03 = 20.13 20.43 a

4.19 4.12 = 27.26 27.284 b

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TABLE 2

Experimental values of total vapour pressures, P, for the various systems of acetone at 273.15 K

a Xl

a

flO@

x1

;4,,r)

Acetone + CH,Cl 2 Acetone + CH,ClCH,Cl 0.0000 145.25 0.0000 21.05 0.1145 127.26 0.1625 26.20 0.2063 113.75 0.2489 29.67 0.2316 110.78 0.3323 32.94 0.3618 95.42 0.3568 34.30 0.4640 87.47 0.4351 38.66 0.5470 81.78 0.5047 41.38 0.6296 77.36 0.5610 44.14 0.7792 70.94 0.6279 47.52 0.8654 69.92 0.7042 50.94 0.9439 69.55 0.8161 57.60 1.0000 70.30 0.8935 62.31

1.0000 70.30

Acetone + CHClCCl 2 Acetone + CC1 &Cl z 0.0000 20.13 0.0934 28.33 0.1878 33.28 0.2827 37.91’ 0.3587 41.34 0.4593 45.39 0.5310 49.04 0.5908 51.53 0.6420 53.99 0.7288 58.20 0.8028 61.38 1 .oooo 70.30

Acetone + c-GH,, 0.0000 0.1522 0.2361 0.2775 0.4126 0.5601 0.6611 0.7211 0.8261 0.9368 0.9628 1.0000

27.26 69.38 75.19 76.52 79.79 80.29 80.51 80.94 80.01 76.26. 74.34 70.30

o.oooo 4.19 0.1250 35.09 0.2178 44.35 0.4143 52.00 0.4649 53.93 0.5645 55.62 0.6625 58.05 0.6980 58.26 0.8596 62.63 0.9485 66.75 1.0000 70.30

a x1 refers to the mole fraction of acetone.

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0.0 0.2 04 06 08 1.0

3

Fig. 1. Plot of the values of the total pressures, P, against mole fraction of acetone, xl, the various systems at 273.15 K. O, acetone+CH,Cl,; 0, acetone+CHClCC12.

for

1953) assuming the vapour phase to behave ideally. Accordingly, gE is expressed as

where a, b and c are constants characteristic of a system at a given

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0.0 0.2 0.4 0.6 68 I.0 Xl

Fig. 2. Plot of the values of the total vapour pressures, P, against mole fraction of acetone, xl, for the various systems at 273.15 K. El, acetone+CH,ClCH,CI; V, acetone+CCl,CCl,; A, acetone+ c-GH,,.

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TABLE 3

Values of the constants a, b and c of eqn. (1) for the various systems of acetone at 273.15 K

System

Acetone + CH,Cl, Acetone + CH,ClCH,Cl Acetone + CC1 &Cl 2 Acetone + CHClCCl, Acetone + c-qH12

a b

(J mol-‘) (J mol-‘)

- 2090.3 474.9 - 900.0 - 32.39 3607.2 - 263.4

697.7 - 426.5 4468.4 - 72.67

6 mol-‘)

- 557.8 - 844.9

- 36.8 307.5 295.7

temperature, and x1 and x2 refer to the liquid phase mole fractions of components 1 and 2, respectively. The values of the constants a, b and c of eqn. (1) with x1 for acetone, as evaluated from the total vapour pressure/ composition data for acetone + CH,Cl,, acetone + CH,ClCH,Cl, acetone + CHClCCl,, acetone + CCl,CCl, and acetone + C-C,H,, at 273.15 K are given in Table 3.

1200

1000 1 8OC

600

,-

, -

I-

l-

b-

/

c

0

-200

-400

-600 I I I I

V cl.2 04 06 0.8 1.0 Xl

Fig. 3. Plot of the experimental values of the excess Gibbs free energies, gE, against mole fraction of acetone, x1, for the various systems at 273.15 K. a, Acetone+c-GH,,; b, acetone + CC1 &Cl *; c, acetone + CHClCCl 2; d, acetone + CH,ClCH,Cl; e, acetone + CH&l,.

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The values of gE for the various systems as obtained from eqn. (l), using the constants a, b and c of Table 3, are represented graphically in Fig. 3. The data show that the values of gE are highly positive for acetone + c-C,H,,. For acetone + CCl,CCl,, gE is less positive than that for acetone + C-C6Hi2, and gE for acetone + CHClCCl, is much less positive than that for acetone + c-C,H,, and acetone + CC1 &Cl,. The values of gE are negative throughout the whole range of composition for acetone + CH,ClCH,Cl and acetone + CH,Cl,. At any fixed composition, the values of gE for the various systems have the sequence:

&+,H,, > &,cc1, ’ g&cc,* ’ g&CH,CI > g&I*

The low positive values of gE for acetone + CHClCCl, and the negative values of gE for acetone + CH,ClCH,Cl and acetone + CH,Cl, show that there exists a specific interaction leading to the formation of molecular complexes between the components of these systems.

ACKNOWLEDGEMENTS

The authors are extremely grateful to Prof. S. Giri, Head of the Chemistry Department, University of Gorakhpur, Gorakhpur, for providing laboratory facilities and to Miss Renu Saini for her help during the investigation. Thanks are also due to the Council of Scientific and Industrial Research, New Delhi, India, for financial support.

REFERENCES

Acharya, M.V.R. and Rao, C.V., 1953. Vapour-liquid equilibria of non-ideal solutions. Part I. Binary systems: (i) acetone-carbon tetrachloride, (ii) acetone-trichloroethylene and (iii) carbon tetrachloride-trichloroethylene. Trans. Indian Inst. Chem. Eng., 6: 129-136.

Adcock, D.S. and McGlashan, M.L., 1954. Heats of mixing. Proc. R. Sot. London Ser. A, 226: 266-282.

Barker, J.A., 1953. Determination of activity coefficients from total vapour pressure measure- ments. Aust. J. Chem., 6: 207-210.

Dakshinamurty, P. and Rao, C.V., 1955. Vapour-liquid equilibria. Systems:-Acetone-tetra- chloroethylene, chloroform-tetrachloroethylene. Trans. Indian Inst. Chem. Eng., 8: 57-66.

Fordyce, C.R. and Simonsen, D.R., 1949. Cellulose ester solutions. Evaporation in binary solvent mixtures. Ind. Eng. Chem., 41: 104-111.

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Iino, M., Nakae, A., Sudoh, J., Hirata, M. and Hirose, Y., 1971. Removal of a small amount of methylene chloride in acetone by extractive distillation employing salt as separating agent. J. Chem. Eng. Jpn., 4: 22-26.

Kurmanadharao, K.V. and Rao, C.V., 1957. Binary vapour-liquid equilibria of the systems methyl ethyl ketone-cyclohexane and acetone-cyclohexane. Chem. Eng. Sci., 7: 97-101.

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Nath, J. and Dixit, A.P., 1984a. Ultrasonic velocities in, and adiabatic compressibilities and excess volumes for, binary liquid mixtures of acetone with tetrachloroethylene, trichloro- ethylene, methylene chloride, 1,2dichloroethane and cyclohexane. J. Chem. Eng. Data, 29: 313-316.

Nath, J. and Dixit, A.P., 1984b. Binary systems of acetone with tetrachloroethylene, trichloro- ethylene, methylene chloride, 1,Zdichloroethane and cyclohexane. 2. Viscosities at 303.15 K. J. Chem. Eng. Data, 29: 317-319.

Nath, J. and Dixit, A.P., 1985. Binary systems of acetone with tetrachloroethylene, trichloro- ethylene, methylene chloride, 1,Zdichloroethane and cyclohexane. Part 3-Dielectric properties and refractive indices at 303.15 K. J. Chem. Sot. Faraday Trans. 2, 81: 11-19.

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Riddick, J.A. and Bunger, W.B., 1970. Techniques of Chemistry Vol. II. Organic Solvents, Physical Properties and Methods of Purification, 3rd edn., Wiley-Interscience, New York.

Timmermans, J., 1950. Physico-Chemical Constants of Pure Organic Compounds. Elsevier, Amsterdam.