232 



Tables 256-257. 



LATENT HEAT OF VAPORIZATION. 



TABLE 255. — Formulae for Latent and Total Heats of Vapors. 



r = latent heat of vaporization at t° C; U = total heat from fJuid at o° to vapor at t° C. 

 scale. Same units as preceding table. 



T' refers to Kelvin 



TABLE 256. — Latent Heat of Vaporization of Ammonia. 

 CALORIES PER GRAM. 



Osborne and van Dusen, Bui. Bureau Standards, 14, p. 439; 1918. 



TABLE 257. — " Latent Heat of Pressure Variation " of Liquid Ammonia. 



When a fluid undergoes a change of pressure, there occurs a transformation of energy into heat or vice versa, which 

 results in a change of temperature of the substance unless a like amount of heat is abstracted or added. This change 

 expressed as the heat so transformed per unit change of pressure is the "latent heat of pressure variation." It is ex- 

 pressed below as Joules per gram per kg cm', Osborne and van Dusen, he. cit., p. 433, 1918. 



