b AET. 11. — T. YAMAMOTO : THE FUSION CURVES 



would be very unstable. They would be dissociated to such 

 extent, that they might be left out of consideration without 

 afiecting the accuracy of the calculation. 



2. The Fusion Curve of Naphthalene. 



In the graphical representation of the fusion curve the com- 

 position of the solution, which is in equilibrium with the solid 

 phase, is taken as the abscissa and the temperature as the ordinate, 

 or vice versa. To express the composition it is usual to emj)loy 

 the molar fraction calculated by using the simplest molecular 

 formula. This may be called the empirical molar fraction in 

 contrast with the actual molar fraction, to calculate which the 

 quantities of all the chemical species must be taken into con- 

 sideration. 



When Ä stands for the number of gramme molecules of 

 naphthalene CioHg in the solution, and JV for the number of 

 gi'animc molecules of phenol calculated with the simplest molecular 

 formula CgHijO, then tlie empirical molar fraction of naphthalene 

 is expressed by the following equation : 



A 



X = 



A + N ' 



This can also be expressed in terms of actual molar fractions. 

 The actual molar fraction of naphthalene is I — C1—C3, because 

 the sum total of molar fractions is always unity. Hence 



^ 1 — Ci — 6 3 l — C-^—C^ / .X 



(i_6',-6y+6'j + 3 6'3 1 + 2 6*3 ^ ^ 



The actual molar fraction of naphthalene l — Ci—C-^ can be 



I 



