T H E J O U R N A L OF I N D U S T R I A L A N D ENGINEERING C H E M I S T R Y
May, 1919
WASHINGTON TABLFVIII-DATA c)N WEATHERCONDITIONS,
Total Averaee - - - - - RadiaP.re: Average - M e a n tion cipi- Days on Rela- Temper- Cals. tation which It tive Hu- ature per Sq. Inch Rained midity Deg. F. Cm. 45 16,588 0.136 18 64 52 4,856 0.006 1 56 50 4,183 0.331 7 75 58 6.758 0.137 6 60 69 9,061 0.086 5 66 75 7,514 0.085 5 73 .. 48,960 0:i34 66 55 43 7 3,111 81 75 0.084 4 3 622 4 68 76 0.087 4:085 71 4 60 0.061 3,627 0.010 69 2 61 6 465 67 69 0.080 5 6:935 0.128 6 63 72 6,941 7 74 78 0.130 34,786 69 i3 497 0 : 092 A". . .-
No. DATES Days Feb. 14-Mar. 2 7 . . . 42 10 Mar. 28-Apr. 6 . . Apr. 7-Apr. 20 ....... 14 14 Apr. 21-May 4 17 M a y 5-May 21.. 15 M a y 22-June 5 . . TOTAL 112 DAILYAVERAGE M a y 25-May 31. Tune I-Tune 7.. June 8-june 14. 7 June 15-June 21.. 14 June 22-July 5.. July 6-July 19.. 14 14 July 20-Aug. 2.. TOTAI 70 DAILYAVERAGE..
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TABLEIX-DATA
~
.. ..
..
..
WEATHERCONDITIONS, PENSACOLA, FLORIDA Average Averaqe Precipi- Days on Average Mean TemNo. tation which It Relative perature DATES Days Inch Rained Humidity Deg. F. 11 0.050 2 84 61 Feb. 18-Feb. 28 14 0.004 1 90 67 Mar. 1-Mar. 14... 7 0.011 1 70 61 Mar. 15-Mar. 21.. 25 0.231 6 79 62 Mar. 22-Apr. 15.. 20 0.415 6 85 66 Apr. 16-May 5 12 0.095 1 87 72 M a y 6-May 17.. 11 0.001 1 80 75 M a y 18-May 28.. 3 7P 79 M a y 29-June 11.. 14 0.058 67 DAILYAVERAGE,. 114 0.147 82 ON
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SUMMARY
With t h e exception of Kenyon Company fabrics, P-298, P-197, and P-198, t h e different. fabrics deteriorate only very slowly over a period of 100 days; there is a general relation between increase in acetone extract and increase in permeability; t h e
r
fabrics exposed from February t o June (average temperature 58' F.) deteriorate more slowly t h a n those exposed in the warmer weather from June t o August (average temperature 73 O F . ) ; fabrics exposed with rubber side down showed no appreciable deterioration over t h e whole period; fabrics exposed rubber up, b u t shielded from ultraviolet light, deteriorated at about t h e same rate as those exposed t o t h e direct rays of t h e sun; and there is no apparent relation between t h e results of weather aging and an accelerated aging test a t 130' C. Tensile strength of all fabrics is decreased about 1 5 per cent b y t h e exposure. Exposure t o high concentrations of phosgene for I j hrs. rots t h e fabric and rubber. Chemical analysis of t h e fabrics appears t o indicate t h a t over I O per cent bitumen is undesirable and t h a t as high as 2 0 per cent of carbon tends t o preserve t h e fabric, especially when exposed t o sunlight. Fabrics with a high percentage of gum are, in general, more resistant t o t h e effects of weather t h a n those containing a large amount of filler. Results indicate t h a t any of t h e fabrics tested, with t h e exception of t h e Kenyon Company fabrics, are satisfactory from t h e point of view of resistance t o weather. GAS MASK RESEARCHSECTION RESEARCHDIVISION, C. W. S , U. S. A. AMERICANUNIVERSITYEXPERIMENT STATION WASHINOTON, D. C.
I
ORIGINAL PAPERS
THE DETERMINATION OF THE FREEZING-POINT CURVES AND DENSITIES OF DENATURED ALCOHOL-WATER MIXTURES By CLARKEE. DAVIS AND MORTIMERT. HARVEY Received December 27, 1918 INTRODUCTION
The great importance of denatured alcohol as a means of protecting t h e radiator and cooling system of automobiles, air planes, and trucks from freezing has prompted t h e authors t o undertake a n investigation of t h e freezing-point curve of mixtures of completely denatured alcohol and water. This information is necessary in order t o determine how much denatured alcohol should be added in order t o secure protection t o a particular temperature. While t h e curve for mixtures of ethyl alcohol and water has been previously investigated, we have found no record of any work on completely denatured alcohol-water mixtures. The object of this investigation has been t o determine t h e temperatures at which equilibrium exists in systems in which t h e liquid phase is composed ofcompletely denatured alcohol and water and in which t h e solid phase is ice. H I ST ORICAL
Raoultl states t h a t mixtures of alcohol and water when subjected t o low temperatures congeal b u t never completely solidify. T h a t which solidifies con1
443
Compt. rend., 90 (1880). 865.
sists of plates of pure ice and can be freed from alcohol by simple mechanical means. Alcohol Volume in 100 g. Alcohol Water Per cent Grams 0.0 0.0 1.6 1.32 3 2 2.65 4.8 3.97 6.3 5.50 7.8 6.62 9.2 7.95 10.6 9.27 11.8 10.60 13.1 11.90 14.2 13.00 16.4 15.30 18.7 17.80 20.4 19.80
.
Temperature of Congelation Deg. C. -0.0 -0.5 -1.0 -1.5 -2.0 -2.5 -3.0 -3*5 1 -4.0 4 . 5
-5.0 -6.0 -7.0 -8.0
Volume Alcohol Per cent 21.9 23.3 26.4 29.1 31.3 33.8 36.1 t38.3 40.0 41.6 43.7 46.2 47.9
Alcohol in 100 g. Water Grams 21.90 23.60 27.60 31.30 35.10 39.00 42.80 46.60 50.60 54.80 59.20 64.40 70.00
Temperature of Congelation Deg. C. -9.0 -10.0 -12.0 -14.0 -16.0 -18.0 -20.0 -22.0 -24.0 -26.0 -28.0 -30.0 -32.0
These results are graphically represented by t h e curve of Fig. I . Pictetl gives t h e following results of t h e determination of t h e freezing points of mixtures of ethyl alcohol a n d water. Alcohol
Per cent
by Weight 2.5 4.8 6.8 11.3 13.8 16.4 17.5 18.8 20.3
Point of Crystallization Deg. C. -1.0 -2.0 -3.0 -5.0 -6.1 -7.5 -8.7 -9.4 -10.6
Alcohol Per cent b y Weight
Point of Crystallization Deg. C.
46.3
-33.9 -41.0 -51.3
56.1 71.9
The author noted t h e temperature a t the appearance of crystals while t h e mixture was being cooled. 1
Compt. rend., 119 (1894), 678
T H E J O U R N A L OF IiVDUSTRIAL A N D ENGINEERING C H E M I S T R Y
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Vol.
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No. 5
It is impossible t o see with accuracy t h e exact temperature a t which the solid phase appears or disappears. I t is more accurate t o determine t h e melting point t h a n the freezing point. It is still more accurate t o determine the melting point by measuring t h e resistance and determining, b y a series of readings a t slowly increasing temperatures, the break in t h e curve which indicates the change from t h e solid t o the liquid phase. EX P E R I hl E N T A L P R 0 C E D URE-A 40 PfRCfNTAGE
VOLUME COMPOSI rIoN
I
50
The temperature changes were all detected b y means of a nickel resistance thermometer, T, with three leads. The amount of inflection or increase in resistance due t o t h e melting was measured by t h e
I
FIG. 3-ARRANGEMEXT
10
20
FIG.2-l?REEZING-POINT
30
40
50
60
70
84
CURVE, ALCOHOL AND WATER, DETERMINED BY PICTET I N 1895
Above -3 j O mercury thermometers and below -3 j " toluene thermometers were used. The former were calibrated in the usual way and the latter by check2 ") ing against carbon dioxide-alcohol paste (-78. and pure ethyl acetate (-82.8 "). 1 2
J . Chem. SOL.,87 ( 1 9 0 5 ) 1 0 3 7 . J .4m Chem Soc., 38 (1916),1712.
OF
APPARATUS
standard Leeds and Northrup Wheatstone bridge, R. T and R, a d'Arsonval, two dry cells, agd a s h u n t box are connected, as shown in Figs. 3 and 4. The melting points of water and various concentrations of denatured alcohol by 2 1 / 2 or 5 per cent increments up t o g o per cent alcohol were determined. The freezing mixture was a paste of carbon dioxidealcohol which, after resting for a time, shows a definite This was contained in a temperature of - 7 8 . 2 O . l quart thermos bottle. The mixture of alcohol and water, made up volumetrically from calibrated burettes, was contained in a test tube 6 in. X I in. This was frozen by immersion in t h e carbon dioxide-alcohol paste. For t h e meltingthe test tube containing t h e frozen mixture was placed in a Janus bottle as shown in Fig. j. I n order t o make t h e rate of heating very slow, t h e neckless bottle, E,was made t o hold t h e loaded testtube. This allows t h e presence of a film of cold air between the melting solid and t h e cold bath, keeping Travers, PYOCR o y . SOC.,I4 (1905), 5 3 4 .
the t~iiiperatiue gradicnt ab IOU as p o s ~ i b l c TIic ch'inge of tempeiaturc was about o o j y per inin 1 The whole magma was kept constantly in iuotion hy a stirrer made of brass, 8 in long and 3 / i i i in in
motor The thiee id nickel remtniiLe thcrniomcter was c.rl~bratcc! aqainst hnunn teinpcr&tuics in orc!ier that interpolation might be ]practiced betwecn tliesc working limit? t o get t h c c x x t tcmperdtui c corrciponilmg t o any r e ~ i s t m c e ( 5 c e Fig 6 ) The points used m e n the melting points of I C C , melting point of mercury, and the coiibtant tcmperature of carbon dioxide-alcohol p:iste. Ice >lWC"*\
Cxbcm diovde alcohol p r i t e
1 lie results are gi\cn in Table 1. The mercury used was first nashed with nitric acld
yl alcohol possessed the following
The limits are The denatured alcohol n a s made in the following proportion .'
Ij
to
25
cc.
C#'%+.W7tM
c
100 pacts ethyl rlcoho! IO P a t . meihy: nleohol #/% part 1,enzoiene
This is known commercially as IJyro. The actual amounts used were z liters of ethyl alcohol, zoo cc. of methyl alcohol, and I O cc. of benzolcnc.
.
E X P E R I M E K T A L DATA SPECIIWATIONS O N XATEKIALS~-(~) The spccific gravity of the ethyl alcohol was 0.811 a t zoo C.
2
.
J. A m . Chem. Suc., Z. D h ? i i i . Chrm., S
firations required.
at
20'
C.
It should he
0.800
at
T E E J O U R N A L OF I N D U S T R I A L A N D ENGINEERING C H E M I S T R Y
446
I
I 100% WATER
Vol.
11,
No. 5
nb
94.
/2% ALCOHOL
4%
ALCOHOL
8% ALCOHOf
26%
ALCOHOL
30% ALCOHOL
90.
e2 8i2'9.0 0
10
20
30
40
$0
/O
6 2% ALCO~~OL
40% ALCOHOL
I
I
20
30
40
50
4
70 % A L coHOL
I
FIG. 7
point varied from I jo' t o 265' C. a t a pressure of 30.05 in. It should range from 150Oto 200' C. a t 30 in. A series of measurements of the melting curves was made a t 35 different concentrations. See Table I1 and the individual melting curves in Fig. 7, TABLE I-DATA -Mercury Time 11.20 11.21 11.22 11.221/2 11.23 11.231/8 11.24 11 .241/z 11.25 11.251/8 11.26 11.27 11.271/a 11 .28+ 11.29 11.291/2 11.30 11.31 11.32 11.33 11.34 11.35 11.36 11.38 11.39va 11.41 11.42
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ON CALIBRATION OF ResistanceOhms
75.0 75.7 78.6 79.1 79.7
.....
80.60 80.90 81.08 81.10 81.12 81.12 81.12 81.12 81.12 81.12 81.12 81.12 81.12 81.12 81.20 81.28 81.40 81.70 81.90 82.60 83.20
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Above 70 per cent of completely denatured alcohol the degree of accuracy of t h e melting points is somewhat less as it is impossible t o get t h e m. p. from t h e resistance, there being no break in the curve. Observation of t h e point of disappearance of crystals, however, enabled us t o get t h e melting point. T h a t NICKELRESISTANCE THERMOMETER they fall directly on t h e curve, Fig. 9, is evidence t h a t -Water ResistanceTime Ohms they are reasonably correct. 12.58'/2 12.591/~ Table I11 gives t h e per cent of denatured alco1.01 1.02 hol in water and t h e corresponding point of crystalliza1.03 1.04 1.05 1.06 1.07 1.08 1.09 1.10 1.11 1.12 1.13 1.14 1.15 1.16 $'1.17 -1.27 1.33 1.43 1.47 1 .50 1.56 2.00 2.03 2.05 2.08 2.10
....
,
Y5.ZU
A second series was made independently with such accuracy t h a t one curve coincides with the other (see Fig. 8). Fig. 8 shows t h e results of plotting the resistance in ohms a t the time of complete melting against t h e percentage composition.
tion, this temperature in degrees Centigrade being taken from the curve (see Fig. 6). Fig. g shows t h e curve obtained by plotting the melting point in degrees Centigrade against percentage composition.
T H E J O U R N A L OF I N D U S T R I A L A N D E N G I N E E R I N G C H E M I S T R Y
May, 1919
447
TABLE 11-DATA Water or 0 per cent Alcohol Resistance Ohms Time 8.01 91.02 92.80 8.021/s 93.10 8.03 8.031/n 93.18 93.20 8.04 93.23 8,04'/n 93.23 8.05 8.05 1/a 93.23 93.23 8.06 93.23 8.06'/a 93.23 8.07 93.23 8.07'/r 93.23 8.08 93.23 8.081/¶ 93.23 8.09 93.23 8.101/t 93.23 8.14 8.15 93.23 93.23 8.16 93.23 8.17 8.18 93.24 8.19 8.20 8.21 8.22 8.24 8.251/2 8.29 8.31 8.32% 8.331/2
14 Per cent Alcohol Resistance Time Ohms 90.50 3.24 90.68 5.25 90.68 90.68 90.70 3.29 90.72 3.30 3.33 90.74 3.35 90.79 3.41 3.43 3.45 3.47 3.49 3.53 3.55 3.59 4.03 91.22 4.05 4.10 91.27 A 1s 91.32 91.36 4.18 91.43 4.27 91.48 4.32 91.52 4.37 4.40 91 -54 91.57 4.44 91.57 4.45 91.58 4.46 91.59 4.47 91.61 4.49 91.62 4.50 91.63 4.51 91.65 4.52 91.70 4.53 91.77 4.54 91.85 4.55 91.92 4.56 92.08 4.57
4 Per cent Alcohol Resistance Time Ohms 91.68 9.33 9.34 91.78 9.37 91.95 9.38 92.03 9.39 92.07 9.40 92.10 92.14 9.41 92.18 9.42 9.43 92.21 92.22 9.44 9.45 92.25 9.46 92.28 92.30 9.47 9.48 92.35 9.49 92.38 92.40 9.50 92.44 9.51 92.48 9.52 92.50 9.53 92.52 9.54 92.54 9.55 92,56 9.56 0
