HENRY'S LAW 323 



TABLE XLIV 



Solubility of CO^ in Water at 15° C. 

 1'. V. v./p. 



where p = pressure in mm. of Ha; of CO.^, 



V = volume of CO., (measured at N.T.P.) absorbed by 1 c.c. of water 

 atl5°C. 



(The same volume of gas at constant temperature is absorbed by the fluid, 

 no matter what the pressure is. Increase of pressure proportionately increases 

 the weight of unit volume. Thus, if 1 volume of water dissolves 1 volume of 

 gas weighing 1 gram at 1 atmosphere pressure, then, if the pressure be raised 

 to 2 atmospheres, 1 volume of water would dissolve 1 volume of the gas 

 weighing 2 grams, or if reduced to normal pressure. 1 volume of water would 

 dissolve 2 volumes ot the gas w^eighing 2 grams.) 



Absorption coefficient (u.sually denoted by the Greek letter a). 



Uifi'erent gases, just like different solids, vary in their solu- 

 bilities. The vohime of gas (at N.T.P.) which dissolves in 1 c.c. 

 of water under a pressure of 1 atmosphere is termed its absorp- 

 tion coefficient, e.g. 1 c.c. of water will dissolve at N.T.P. 0-0489 c.c. 

 of oxygen, 0-0239 c.c. of nitrogen, and 1-713 c.c, of carbon-dioxide. 

 The volume of gas absorbed by 1 c.c. of water under any pressure 

 may be found by the following equation : 



L = aJJ, 

 where L = amount of gas dissolved, 

 a = absorption coefficient, 

 }) = pressure in atmospheres. 



Variations in temperature alter the amount of gas a fluid may 

 take up. 



The amount of gas absorbed by a fluid decreases as the tempera- 

 ture of the fluid (and gas) is increased and vice versa. 



TABLE XLV 



Absorption Coefficients at Various Temperatures 



40° C. 00231 0-0118 0-530 



Effect of solutes. 



Plasma, as we have seen, is a hydrophilic colloid in which a large 

 amount of water is dispersed through a hydrated protein-crystalloid 



21--2 



