Chemistry. — "In-, mono- and divariant equilibria" , XXII. By 



Prof. F. A. H. SCHREINEMAKEHS. 



(Communicated at the meeting of October 28, 1922). 



Equilibria of n components in n -\- 1 phases, when the quantity of 



one of the components approaches to zero. The inflnence 



of a new substance on an invariant equilibrium. 



For the equilibrium : 



E=L\ + i'\ + .-..-} i^,.+i ...... (1) 



of n components in n -\- 1 phases, as we have seen furtherlj, are 

 valid the equations: 



^Zi dZi 



Zi-'^i-. yi~-....=K (2) 



Oxi Oyi 



. (n + 1) 



ÖZ„_|_i._ 



^7 .... (3) 



^yn+i 



to which still must be added the corresponding equations for the 

 variables Zj e, . . . u^ u^ . . . etc. As it is apparent from the number 

 of equations (viz. ?i* -j- n) and the number of variables (viz. n' + ^^ ~i~ 1)» 

 this equilibrium is monovariant, consequently, in the P, ^'-diagram 

 we represent it by a curve, which we call E. 



When in this equilibrium E all phases with constant composition 

 contain together only n — 1 of the n components, so that in these 

 phases one of the components f.i. X is missing, then, in the phases 

 with variable composition the quantity of tiiis component X may 

 approach to Zero. 



Then the equilibrium E passes into an equilibrium, that we call 

 E{x=zO) which consists of n — 1 components in n + 1 phases and 

 that, consequently is invariant; in the /^ jf'-diagi-ani it is represented 

 therefore, by a point which we shall call z(.i' = 0). This point is 

 the invariant terminating — or beginning — point of curve E. 



22 



Proceedings RoyaJ Acad. Amsterdam. Vol. XXV. 



