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Hello everyone,

The problem goes like this:

I had calculated the activity coefficient for a particular multicomponent system at a temperature, lets say 60 C.
Thus I can obtain its relative volatility afterwards.

The question is would the relative volatility of this substance change or stays approximately the same when the T is being increased or decreased by let's say 30 C , considering that this system is a non ideal VLE system?

[MrShorty]

Relative volatility is definitely a function of temperature -- even for an ideal system. Assuming Raoult's law, the relative volatility reduces to the ratio of the pure component vapor pressures, and it should only take a vew minutes for you to verify that that ratio changes with temperature. In order to quantify the relative volatility correctly over a temperature range, you need some information on how the activity coefficient and other VLE parameters (like vapor pressure) vary with temperature.