OF THE SYSTEM NAPHTHALENE-PHENOL. 7 



represented as a function of temperature. As all the chemical 

 species of the system are supposed to fulfill the conditions of the 

 ideal solution, the following relation must hold : 



l_(7,--6'3 = e^^2; t)^ (5) 



in which Q is the molecular heat of fusion of naphthalene, and 

 Tq is its melting point. Q is supposed to be independent of 

 temperature, which is not quite exact, but may be assumed as a 

 tolerable approximation. 



(Ö) 



Putting this value of (/; in (4) and substituting for ^v and @ 

 the expressions given in (3) and (6), we have, 



— -— ) 



Q_( 1 



R 



1 + 



IV 2 +V 4 + 27 



+ V 2 "V ^ 4-^^^ -^7^)-^'^ 



This is the equation sought, for it expresses the empirical molar 

 fraction of naphthalene as an explicit function of temperature, 

 and thus represents the fusion curve. 



