of Miscible Liquids by Distillation. 

 ' dA 



637 



the net flow be -~rr °f substance A, the net flow o£ substance B 

 being zero, the flow past any point must satisfy the equations 

 dV a +dL a =dA 

 and dV b + dL b = dB = ; 



Fig. 1. 



Mixture of Benzene and Toluene. 



The Composition of Phases in Equilibrium at Atmospheric Pressure 

 for different Temperatures. 



VAPOUR 



50 

 55 PER CFNT 



100 BENZENE 

 O TOLUENE 



moreover, since the flow of each component in the liquid or 

 vapour is proportional to the amount present in that phase, 



dh a __ L a 

 dLi& L& 



dV a V a 



and 



dVb ~ V 



