The Physical Properties of the Ternary System Ethyl Alcohol–Glycerin

by various experimenters. The binary system ethyl alcohol-water has been investigated by Bose (6),who determined specific heats, and by. Winkler (22) ...
1 downloads 0 Views 381KB Size
THE PHYSICAL PROPERTIES OF THE TERNARY SYSTEM ETHYL ALCOHOL-GLYCERIN-WATER1 R. C. ERNST, C. H. WATKINS, AND H. H. RUWE Chemical Engineering Laboratories, University of Louisville, Louisville, Kentucky Received January 2, 1936 INTRODUCTION

This and a previous investigation (10) were undertaken to obtain data to be used in the study of distillation of ternary mixtures. The densities, surface tensions, viscosities, refractive indices, and specific heats for the ternary system ethyl alcohol-glycerin-water are reported in this paper. A later paper will contain latent heats, boiling points, vapor pressures, and liquid-vapor composition data for the two ternary systems. Densities (4),specific heats (13), refractive indices (ll), and viscosities (19) of the binary system glycerin-water have been determined previously by various experimenters. The binary system ethyl alcohol-water has been investigated by Bose (6), who determined specific heats, and by Winkler (22) for density. This investigation includes the determination of densities, surface tensions, viscosities, refractive indices, and specific heats of the ternary system ethyl alcohol-glycerin-water. EXPERIMENTAL

Materials. Glycerin of the C.P. grade was purified by repeated distillation under reduced pressure. C.P. ethyl alcohol was treated successively with metallic calcium, sodium hydroxide, and finally with metallic sodium, and distilled after each addition. The water was treated with potassium permanganate and distilled ; then treated with barium hydroxide and distilled repeatedly. The physical constants of the purified materials are given in table 1. Preparation of samples. The samples were prepared on a weight per cent basis in increments of 10 per cent. The composition of these samples is shown in table 2. Apparatus. Densities were determined by using a Geissler pycnometer. An Ostwald-Poiseuille viscosimeter (23) was employed for the determination of viscosities. The surface tension was measured by means of the 1 Presented before the Division of Physical and Inorganio Chemistry at the Mid-West Regional Meeting of the American Chemical Society, October 31 to November 2, 1935.

627 TBE JOURNAL OF PEYBICAL CBEYIBTRY, VOL.

40, NO, 5

628

R. C . ERNST, C. H. WATKINS, AND H. H. RUWE

rise in a capillary tube (21). An Abbe refractometer (1) was used in obtaining refractive indices. Specific heats (17) were determined by introducing a measured quantity of electricity into the liquid and recording the temperature rise. ii portable watt-second meter (Sangamo Electric Co.) and a thermometer with 0.1" graduations were used to determine these values. A carbon resistor was used as a heating element. This apparatus was inclosed in a silver-plated glass tube surrounded by an evacuated jacket. TABLE 1

Physical constants o j purijed materials MATERIAL

DENSITY

I

VISCOSITY

SURFACE TENSION

1

REFRACTIVE INDEX

SPECIFIC H E A T

Ethyl alcohol

0.7851* 0.78506 (14)t 0.78510 (22)

1.10+ 1.101 (9)

22.0* 22.03 (3)

1.3596* 1.35941 (2)

0.536* 0.54 (16)

Glycerin

1,2580* 1.2580 (4) 1,25802 (5)

934* 945 (19)

62.5* 63.0 (8)

1.4729* 1.4730 (11)

0.555*

0.99707 0.99707 (20) 0.99707 (7)

0,893 0.894 (12) 0.893 (18)

72'0 72.0 (16)

1.3332* 1.3325 (15) 1.3333 (10)

1.oo

Water

* Author's

1

0.541 (13) 0.589 (13)

experimental values.

t The numbers in parentheses refer t o the bibliography. DISCUSSION

Theresultsof theexperimentalworkareshownin table 3. From the data obtained, both binoidal and triangular diagrams have been drawn for each physical property. The binoidal curves are plotted with the composition of the sample on the abscksa versus the particular property under consideration as the ordinate. The constant property lines on the triangular diagrams were prepared from the binoidal curves. Relative density. Figure 1 is a binoidal graph of the relative densities against composition. The line representing the densities of the ethyl alcohol-water system curves upward, indicating a decrease in volume upon mixing. These values agree with those of Winkler (22). The densities of the ethyl alcohol-glycerin system lie between the values €or alcohol and glycerin, but likewise show a decrease in volume upon mixing. The water-glycerin curve slopes downward, denoting a slight increase in volume when mixed, agreeing with Bosart and Snoddy (4). The constant per cent glycerin curves and the constant per cent ethyl alcohol curves show a curvature similar to the ethyl alcohol-water and the

TERNARY SYSTEM ETHYL ALCOHOL-GLYCERIN-WATER

629

glycerin-water curves, respectively. The characteristic curvature of the lines on the triangular diagram (figure 2) is to be expected because of the change in volume when the different components are mixed.

TABLE 2 Composition of the samples SAMPLE NUMBER

WEIGHT

PER CENT 3LYCERlN

,EIGHT PEE DNT ETHYL ALCOHOL

HEIGHT PER ENT WATER

SAMPLE NUMBER

WEIGHT PER CENT GLYCERIN

VEIQHT PEE ENT ETHYI ALCOHOL

50 40 30 20 10 70 60

10 10

WEIGHT PER CBNT WATER

~~

1 2 3 4 5 6 7 8 9

100

100 10 20 30 40 50 60

10

70

11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33

80 90

100 90 80

70 60 50 40 30 20 10

90

10

80

20 30 40 50 60 70 80 90

70 60 50 40 30 20 10

10 20 30 40 50

60 70 80 90 80

70 60

90 80 70 60 50 40 30 20 10 10 10 10

10 20 30

34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 E4

55 56 57 58 59 60 61 62 63 64 65 66

50

40 30 20 10 60 50 40 30 20 10 50 40 30 20 10 40 30 20 10 30 20 10 20 10 10

10

10 10 20 20 20 20 20 20 20 30 30 30 30 30 30 40 40 40 40 40 50 50 50 50

60 60 60 70 70 80

40 50 60 70 80 10 20 30 40 50 60 70 10

20 30 40 50 60 10

20 30 40 50 10 20 30 40 10

20 30 10 20 10

Surface tension. The curve (figure 3) representing the binary system ethyl alcohol-glycerin is smooth but rises abruptly from the 80 per cent glycerin composition. The constant per cent water lines have the same characteristic curvature. The surface tensions of the water-glycerin mixtures are between the

630

R. C. ERNST, C. H. WATKINS, AND H. H. RUWE

TABLE 3 Physical properties SAMPLE NUMBE

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46

DENSITY

YISCOSITY

0.7851 1 .2627 1.oooo 0.9833 0.9692 0.9535 0.9342 0.9125 0.8895 0.8659 0.8415 0.8160 1.2356 1,2089 1,1819 1,1545 1.1272 1.1003 1.0738 1 0484 1.0237 0.8199 0.8566 0.8947 0.9368 0.9806 1.0288 1,0797 1.1366 1.1932 1,1724 1.1484 1.1212 1.IO04 1.0776 1.0514 1,0270 1.0025 1.1165 1.0988 1,0753 1.0525 1.0318 1.0101 0.9882 1.0618

1.10 934.0 0.893 1.33 1.76 2.13 2.34 2.33 2.24 2.04 1.72 1.41 155.6 55.8 18.5 9.38 5.34 3.18 2.14 1.54 1.09 1.52 2.23 3.49 5.83 10.4 20.6 45.3 103.3 254.0 74.6 26.2 14.1 7.42 4.75 3.13 2.22 1.69 41.1 16.9 9.29 5.91 4.04 2.92 2.20 19.50

SURFACE TENSION

REFRACTIVE INDEX

22.0 62.5 72.0 46.6 37.7 32.3 29.6 28.3 26.9 26.1 25.2 24.4 64.5 65.7 66.5 66.9 67.4 67.9 68.5 69.5 70.5 22.9 23.9 24.2 25.4 26.1 27.7 29.6 32.7 38.9 40.4 39.9 40.4 41.3 42.7

1.3596 1.4729 1,3332 1,3399 1,3453 1.3510 1,3552 1,3587 1.3610 1.3628 1.3630 1,3624 1,3472 1.4435 1.4281 1.4145 1.3992 1.3858 1.3708 1.3582 1,3451 1,3701 1.3799 1,3898 1.4005 1.4109 1.4226 1.4344 1,4470 1,4597 1,4462 1.4321 1.4193 1.4063 1.3917 1,3769 1,3639 1.3511 1.4343 1.4220 1.4096 1.3961 1,3827 1.3705 1.3573 1.4235

44.0 45.4 46.4 32.7 33.5 34.6 34.9 35.1 35.9 37.0 30.4

SPECIFIC HEAT

0.537 0.555 1.Ooo 1.036 1.040 0.995 0.964 0.915 0.859 0.784 0.700 0.618 0,579 0.610 0.665 0.715 0.770 0.810 0,870 0.930 0.967 0.550 0.550 0.549 0.548 0.550 0.549 0.549 0.551 0.552

0.581 0.622 0.675 0.741 0.790 0.856 0.921 0.966 0.588 0.635 0.681 0.735 0.810 0.885 0.953 0.591

63 1

TERNARY SYSTEM ETHYL ALCOHOL-GLYCERIN-WATER

TABLE 3-Concluded SAMPLE N U Y B E U

47 48 49 50

51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66

1

DENSITY

1.0460 1 ,0273 1.oO90 0.9888 0.9690 1.0149 0.9984 0.9821 0.9655 0.9486 0.9670 0.9553 0.9430 0.9272 0.9282 0.9143 0.9016 0.8889 0.8796 0,8505

1

VIBCOSITY

10.80 6.63 4.60 3.47 2.69 12.3 7.04 4.73 3.57 2.84 6.63 4.59 3.52 2.78 4.26 3.26 2.59 2.88 2.36 2.00

SURFACE TBNSION

30.1 31.3 31.6 32.0 32.8 28.8 28.9 28.9 29.6 29.9 27.2 28.0

27.5 28.3 26.3 26.3 27.0 24.5 25.6 24.6

REFRACTIVE INDEX

SPECIFIC EDAT

1.4112 1.3990 1.3871 1.3749 1.3631 1.4120 1.4006 1.3900 1.3787 1.3672 1.4011 1.3907 1 .3810 1.3700 1.3911 1.3817 1.3717 1.3812 1 ,3721 1.3720

AQLYCLRINE

WElOHT PERCENT WATER

FIQ.1 FIQ.2 FIQ.1. Relative density glycerin-ethyl alcohol-water a t 25°C. FIG.2. Relative density glycerin-ethyl alcohol-water a t 25'C'

0.644 0.690 0.754 0.831 0.910 0.592 0.642 0.702 0.775 0.860 0.591 0.648 0.720 0.809 0.582 0.660 0.741 0.610 0.677 0.616

632

R. C . ERNST, C . H. WATKINS, AND H. H. RUWE

68

t 60 /XOLYCERINE

0:

2 52 u)

Y

E

44

13s w

2 28

f

20' 100

I I I i 80 60 40 20 0 WEIGHT PERCENT GLYCERINE

WATER

ETHYL ALCOHOL

FIQ.3 FIQ.4 FIG.3. Surface tension glycerin-ethyl alcohol-water a t 25°C. FIG.4. Surface tension glycerin-ethyl alcohol-water a t 25°C.

WEIGHT PERCENT ETHYL ALCOHOL

WATER

ETHYL ALCOHOL

FIG.5 FIQ.6 FIG,5. Refractive index glycerin-ethyl alcohol-water a t 25'C. FIG.6. Refractive index glycerin-ethyl alcohol-water a t 25°C.

TERNARY SYSTEM ETHYL ALCOHOL-GLYCERIN-WATER

633

A

OLYCERINE

WEIQHT

PERCENT

E T W L ALCOHOL

WATER

ETHYL ALCOHOL

FIQ.7 FIQ.8 FIG.7. Viscosity glycerin-ethyl alcohol-water a t 25'C. FIG.8. Viscosity glycerin-ethyl alcohol-water at 25'C.

FIQ.9 FIG.10 FIQ.9. Specific heat glycerin-ethyl alcohol-water a t 2 5 T . FIG.10. Specific heat glycerin-ethyl alcohol-water at 25°C.

634

R . C. ERKST, C. H. WATKINS, AND H. H. RUWE

values for the pure components; they lie on a smooth curve but not in a straight line. In figure 4 the line representing compositions having a surface tension of 34.0 is a straight line. The lines on either side are convex with respect to this constant property line. Refractive indez. The refractive indices are shown graphically in figure 5 and figure 6. The values of the alcohol-water mixtures lie on a smooth curve reaching a maximum a t 80 per cent alcohol. The constant per cent glycerin lines show similar maximum points. The glycerin-water values curve slightly but are intermediate between the refractive indices of the pure components. The constant per cent water lines have the same curvature as the glycerin-alcohol curve. The constant property lines in figure 6 show a similar curvature throughout. Viscosity. Because of the high viscosity of glycerin, namely 945 centipoises (19), when compared to that of alcohol and water, the curves showing viscosities include only those samples whose glycerin percentages are below 40 per cent. I n figure 7 the alcohol-water mixtures have maximum viscosity at 50 per cent alcohol. The constant per cent glycerin curves show similar maximum points. These maxima explain the shape of the lines in figure 8. Specific heat. Figure 9 shows the specific heat of the system plotted against composition. The specific heat of the water-alcohol system reaches a maximum at 80 per cent water and drops on a smooth curve to pure alcohol. The glycerin-alcohol line is almost straight. The constant per cent glycerin lines show similar curvature, but approach straight lines a t 60 per cent glycerin. The slopes of the lines on the ternary diagram (figure 10) are explained by the constant per cent glycerin lines reaching a maximum. CONCLUSION

Densities, surface tensions, viscosities, refractive indices, and specific heats for the ternary system glycerin-ethyl alcohol-water have been determined. Both binoidal curves and ternary diagrams have been prepared for each property and are included in this paper. REFERESCES

(1) A B B ~E.: , Cads Repertarium der Physik 15, 643 (1879). (2) ANDREWS:J. Am. Chem. Sac. 30,353 (1905). (3) BIRCUMSHAW: J. Chem. Sac. 121, 887 (1922). (4) BOSART AND SNODDY: Ind. Eng. Chem. 19, 506 (1927). (5) BOSARTAND SNODDY: Ind. Eng. Chem. 20, 1377 (1928). (6) BOSE:Z. physik. Chem. 58, 585 (1907). (7) CHAPPIUS:Travaux et memoirs du bureau international des poids e t memure8 13: D 40 (1907).

TERNARY SYSTEM ETHYL ALCOHOL-QLYCERIN-WATER

635

(8) DRUCKER: 2. physik. Chem., Stoiohiometrie und Verwandtschaftslehre 62, 041 (1905). (9) DUNSTAN AND THALE: J. Chem. Soo. 96, 1556 (1909). ' (10) ERNST,LITKENHOUS, AND SPANYER: J. Phys. Chem. 36,842 (1932). (11) IYERAND USHER:J. Chem. Soo. 127,841 (1925). (12) JAYNER:J. Chem. SOC.121, 1511 (1922). (13) MAGIE:Phys. Rev. 16, 381 (1903). (14) OSBORNE, MCKELYY, AND BEARCE: Bur. Standards Bull. 9, 327 (1913). Ann. Physik 44,774 (1891). (15) QUINCKE: AND CARVER: J. Am. Chem. SOC. 43, 827 (1921). (16) RICHARDS AND GUCKER: J. Am. Chem. Soo. 47, 1876 (1925). (17) RICHARDS Ind. Eng. Chem. 24, 1061 (1932). (18) SHEELY: (19) SHEELY:Ind. Eng. Chem. 24, 1063 (1932). (20) THEISSEN, SCHEEL, AND DIESSELHORBT: Wiss. Abhandl. physik. tech. Reichsanstalt 2, 68 (1900). (21) Trans. Chem. SOC.63, 1089 (1873). Ber. S8, 3612 (1905). (22) WINKLER: (23) Wiss. Abhandl. physik. tech. Reiohsanstalt 4,241 (1901).