Question

Question 2

1. For binary VLE systems, alpha = [ the relative volatility ], defined as the ratio of the pure-component vapour pressures at a particular temperature.

   For binary system AB: alpha(AB) = 20

   For binary system CD: alpha (CD) = 0.05

   Consider the following statement:

   System AB is more favourable for separation by distillation than CD

   Is this TRUE or FALSE

Answer 1

True,

The principle on which distillation works is the difference in relative volatility, i,e for a binary mixture to be separated by distillation their relative volatilities must have a value quite far 1, since for the system AB their RV (alpha) is much greater than 1

distillation is favourable for this system.