- (GTR ) = ARN.- --4 Rex lol - A) (b) We now let the droplet radius R be a function of time, and treat the problem as a quasi-steady one. Then the rate of decrease of moles of A within the drop can be equated to the instantaneous rate of loss of mass across the liquid-gas interface (19B.7-3) where is the molar density of pure liquid A. Show that when this equation is integrated from t ='0 tot = t, (the time for complete evaporation of the droplet), one gets R2 (193.7-4) 2c In[1/(1-XAR) Does this result look physically reasonable? AB