Distillation is the process of heating a liquid solution, or a liquid-vapour mixture, to derive off a vapour and then collecting and condensing this vapour. The products of a distillation process are most often limited to an overhead distillate and a bottoms, whose compositions differ from that of the feed.
Alcohol vapor is being absorbed from a mixture of alcohol vapor and water vapor by means of a nonvolatile solvent in which alcohol is soluble but water is not. The temp. is 97 ºC, and Pt=760 mmHg. The alcohol vapor can be considered to be diffusing through a film of alcohol-water- vapor mixture 0.1 mm thick The molal concentration of the alcohol vapor at the outside of the film is 80 %, and that on the inside is, next to the solvent is, 10 %. D Et-OH- water =0.15 cm 2 /sec at 25 ºC and 1 atm. Calculate the rate of diffusion of alcohol vapor in pounds per hour if the area of the film is 100 ft 2 .
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