Solubility of Nitrogen in Water at 25" C. from 25 to 1000 Atmospheres R. WIEBE, I T . L. GADDY,AND CONRADHEINS,JR. Fertilizer and Fixed Nitrogen Investigations, Bureau of Chemistry and Soils, Washington, D. C. The solubility of nitrogen in water at 25" C.,from coefficient (cubic centimeters of gas at S. T. P. per 25 to 1000 atmospheres has been determined. At gram of liquid) of nitrogen in water at 25" c. and 100, 200, and 300 atmospheres two independent 1 atmosphere partial pressure is about 20 per cent mefhods were used. The agreement between the two less than that of hydrogen, but at 1000 atmospheres was within about 0.1 per cent. The absorption nitrogen is less than half as soluble as hydrogen.
G
OODMAN and Krase (3) and Frolich and collaborators
The agreement between the results obtained b y bubbling and shaking as shown in Table I1 is very good and is a good indication of the reliability of both methods.
( 2 ) have published measurements on the solubility of nitrogen in water a t 25" C. which are in disagreemeiit with each other. It seemed, therefore] desirable to repeat some of their work and also to extend their measurements to higher pressures. The present results agree with those of Frolich and associates through 100 atmospheres] but their curve extrapolated from 190 to 200 atmospheres gives a result about 10 per cent higher than that of the present writers a t 200 atmospheres. APPARATCSAKD PROCEDURE. The apparatxs and procedure for obtaining most of the data were identical with those used previously for hydrogen (6). A few additional measurements a t 100, 200, and 300 atmospheres were made by Wiebe and Tremearne in a shaking apparatus to be described in the near future in connection with other work. The nitrogen used was the best commercial obtainable and was further purified by passage over finely divided copper (reduced copper oxide) a t 300" C. This left the argon and traces of oxygen in the gas. The final purity of the gas was estimated to be about 99.9 per cent nitrogen ( 4 ) . TABLE I.
.-
G
c.
(Saturation obtained bv bubblind LOW-PRESSURE HIQH-PRESSURE NITROGER APPROACH A P P R oA c H PRESSURERuns Av. coefficient Runs Av coefficient FINALVALCES Atmospheres CC . Cc. cc . 12 0 . 3 4 8 f 0.000 0 . 3 4 8 I: 0.000 25 10 0 . 3 4 8 f 0 . 0 0 0 50 10 0 . 6 7 5 I: 0.001 0 . 3 7 4 f 0 . 0 0 2 10 0 . 6 7 3 i 0 . 0 0 1 100 10 1 . 2 6 2 f 0 . 0 0 1 7 1 . 2 6 8 f 0.001 1.265 i 0 . 0 0 4 200 6 2.253 f 0.002 6 2 . 2 6 0 i 0.002 2 . 2 5 7 i 0 . 0 0 6 300 10 3 . 0 5 6 i 0.002 3 . 0 5 7 I: 0 . 0 0 5 6 3 . 0 5 8 I: 0 . 0 0 4 600 11 4 . 4 3 1 A= 0 . 0 0 2 10 4 . 4 4 1 f 0.003 4 . 4 3 6 I: 0.008 6.13 f 0.01 15 6 . 1 3 f 0.00 800 5 6 . 1 3 j, 0.01 12 7 . 1 4 f 0.00 14 7 . 1 4 I: 0 . 0 1 7 . 1 4 I: 0.01 1000 0 Cubic centimeters of gas at S . T. P. per gram of water.
TABLE 11. ABSORPTIONCOEFFICIENTS~ OF NITROC~ES IS WATER AT
25'
c.
(Saturation obtained by shaking) NITROGEN PRESSURE RUNS A v . COEFFICIEST .&V, Fl%OM TABLE1 Atmospheres cc . CC . 1 . 2 6 5 I: 0 004 100 14 1 . 2 6 5 I: 0.001 200 13 2 . 2 6 0 I: 0.001 2 . 2 5 7 I: 0 . 0 0 6 300 14 3.059 & 0.002 3.057 i 0.005 Cubic centimeters of gas at S. T . P. per gram of water. ~
Q
DISCESSION OF RESULTS. The experimental results are shown in Tables I and I1 and in Figure 1. The values for the two approaches to equilibrium in the bubbling experiments are given separately in Table I. The errors are calculated from the equation:
E
=
0.674
4 1 n(n - 1)
100
200
300
400
600
500
700
000
900
IOCO
Pressure tn Atm. of Nitrogen
.4BSORPTION COEFFICIENTS" OF NITROGEN IN W a T E R AT 25'
FIGURE 1. SOLUBILITY OF NITROGEX AT VARIOUSPRESSURES X Goodman and Krase.
0 Wiebe, Gaddy, and Heins
Table I11 gives a comparison betu-een the results obtained by the different observers. TABLE 111. COMPARISON OF RESULTS OBTAINED BY DIFFERENT OBSERVERS NITROQEN FROLICH AND GOODMAN WIEBE,GADDY, P R E ssuR E ASSOCIATES" A N D KRlSE A N D HEINS Atmosvheres cc. cc. cc. 25 .. 0 348 50 0:65 0.674 1.265 100 1.28 1:07 2.257 2.76 200 2,50 3.25 300 3.057 500 4.436 6.13 800 7.14 1000 a Values were taken from a blue print sent by Frolich: the values therefore can be only estimates of the actual values obtained.
... .
Cassuto ( 1 ) has determined the solubility of nitrogen in water u p to approximately 10 atmospheres. His value a t 10 atmospheres is considerably lower than the present authors] value a t 25 atmospheres. LITER.4TURE
CITED
(1) Cassuto, Physilc. Z . , 5 , 233 (1904).
(2) Frolich, Tauch, Hogan, and Peer, ISD. ENG.CHEM.,23, 548 (1931). (3) Goodman and Krase, Ibid., 23, 401 (1931). (4) Leatherman and Bartlett. Ibid., 4nal. Ed., 1, 233 (1929). ( 5 ) Wiebe, Gaddy, and Heins, ISD.ESQ. CHEM.,24, 823 (1932) RECEIVED .March 21, 1932.
927
