BIBLIOGKAPHY 41 



in C and T balance each other. In the simple form of reaction 

 P B = K . P A , illustrated in the diagram (p. 36), this is quite clear, for 



T> 



increase in T will cause similar increase in the expression RT log v,? 



^AJ 



and hence will place each point on the curved line farther 

 from the base line, and so bring the equilibrium point, that is, the 

 point where the curved and horizontal line lie at an equal distance 

 from the base line XX', nearer to the mid point. Accordingly 

 increase of temperature acts like low value of chemical energy and 

 increases reversibility. 



In the more complex forms of reaction, such as P B = K . P 2 A , &c.-, 

 the form of the curved line representing change in osmotic energy 

 varies ; it is still asymptotic at both ends, but no longer crosses the 

 zero line at the mid point between X and X'. Hence increases from 

 zero in the value of C in one definite direction only, will up to a 

 certain limit bring the point of crossing nearer the mid point, and 

 so increase reversibility. Similarly, if the value of C is taken as 

 fixed, increases in T up to a fixed limit will decrease the reversibility, 

 but later for higher values will increase it. Hence in those cases 

 where the number of molecules is altered in the reaction there is 

 at a certain given point in each case of change in or change in T, 

 a reversal in the effect. For higher values of C or T, however, 

 effects of increase of C to high positive or negative values is to 

 throw the crossing farther along towards the asymptotic portion of 

 the line at either end, and so diminish the reversibility ; while 

 effects of increase of T at higher values, C being fixed and 

 moderately low, is to throw the crossings further from either end 

 point and so to increase reversibility. 



BIBLIOGRAPHY 



Nernst, Theoretische Chemie, 3 te Aufl., F. Enke, Stuttgart (1900), trans- 

 lation by Palmer. 



Van't Hof, Vorlesungen iiber Theoretische and Physikalische Chemie 

 Vieweg, Braunschweig (1901-1903). 



Ostwald, Lehrbuch der Allgem. Chemie; Grundriss der Allgem. Chemie. 

 Ueber Katalyse, Vortrag, Naturforsch-Versamm., Hamburg (1901), Hirzel, 

 Leipzig (1902). 



Croft-Hill, Journ. of Chem. Soc., Lond., vol. Ixxiii. (1898), p. 634 ; ibid., 

 vol. Ixxxiii. (1903), p. 578 ; Ber. d deut. chem. Gesellschaft, vol. xxxiv. (1901), 

 p. 1380. 



