AUGUST, 1955
TEXTBOOK ERRORS1 111: The Solubility of Gases in Liquids
KAROL J. MYSELS University of Southern California, Los Angeles, California
RISINGtemperature is generallyZ said to reduce the solubility of gases in liquids. The facts,3 however, disagree with any such generalization which is not even true for water, although it summarizes the behavior of many systems. An increased solubility with rising temperature seems generally to be observed for Hz, Nz, CO, He, and Ne in a variety of organic liquids, such as CCL, CsHs, (CH&CO, etc. To quote a few high examples: Lannung4 found the solubility of He to increase by 16.5 per cent in acetone between 15 and 25°C. and by 34 per cent in benzene between 15 and 27°C. For Hz, Horintis found an increase of 43 per cent in CC14 between 0 and 5g°C., and Maxted and Moon' of 38 per cent in benzene between 0.5 and 40°C. A spectacular increase in solubility has been reported for the inorganic system Oz gas in liquid SOz where Dornte 1 Suggestions of material suitable for this column are eagerly sought and will he acknowledged. They should be sent with as many details as possible to K. J. M. a t the above address. 2 Since the purpose of this column is to prevent the spread and continuation of errors and not the evaluation of individual texts, the source of the errors discussed will not be cited. The error must occur in s t least two independent stsndard books to he presented. a Most of the examples quoted and many others may be found in SEIDEL,A,, ''Solubilities of Inorganic and Metal Organic Compounds," D. Van Nostrand Ca., New York, 1940. For a diaH. S., AND M. W. EVANS, eussion of the thermodynamics, FRANK, J. Chern. Phys., 13,507 (1945). 'LANNUNG, A,, J. Am. Chem. Soc., 52, 68 (1930). HORI-, J., Sei. Papers Inst. Phys. Chem. Res. (Tokyo), 17,
125 (1931). 8
MAXTED,E. G.,
i 6 9 (1936).
AND
C. H. MOON,Trans. Faraday Soc., 32,
and Ferguson7 report a 23-fold change between -20 and +30°C. If the solubility is measured not a t constant partial pressure of the gas (Bunsen coefficient) but a t constant concentration in the vapor phase (Ostwald coefficient), the increases become even larger and oxygen in organic solvents joins the list of systems for which they are observed. In case of water, the situation is somewhat less simple. Early measurements as summarized in the "Critical Tables"8 show several increases, some quite large, of solubility with temperature at 760 mm. Hg. These were not confirmed, however, .by more careful work4* and any increase seemed t o be within the experimental uncertainty. Measurements a t high pressure have shown, however, that the solubilities of N2,l0 Hz," and HeL2pass through pronounced minima a t about 70,55, and 30°C., respectively, leaving no doubt that the situation is the same a t 760 mm. Hg or below. Thus, the solubilities of gases in liquids, like other solubilities, may increase or decrease or change sign with temperature. 7
DORNTE, R. W.,
AND
C. V. FERGUSON, Ind. Eng. Chem., 31,
112 (1939).
"'International Clitioal Tables," McGraw-Hill Book Co., Inc., New York, 1928, Val. 111, p. 225, H, He, Ne. O CADY, H. P., H. M. ELSEY,AND E. V. BERGER,J . Am. Chem. Soe., 44, 1 4 5 6 1 6 (1922). WIEBE,R., V. L. GADDY, AND C. HEINS, JR.,ibid., 55, 947 A. W., A N D N. W. KRASE, ibid., 56, 353 (1933); SADDINGTON, (1934). WIEBE,R., AND V. L. GADDY, ibid., 56,76 (1934). 11 WIEBE,R., A N D V. L. GADDY, a i d . , 57,847 (1935).
