Chemical Forums

Chemistry Forums for Students => Physical Chemistry Forum => Topic started by: material on August 09, 2005, 11:00:11 AM

Title: Fugacity
Post by: material on August 09, 2005, 11:00:11 AM

Pls, I need the explanation of the physical property,called fugacity.

Title: Re:Fugacity
Post by: Donaldson Tan on August 09, 2005, 11:32:51 AM

think fugacity as a pseudo pressure.

isothermal change for a perfect gas: dg = v dp = RT (dp/p)

the Gibbs free energy of a real gas is therefore: dg = v dp = RT (df/f) where f is fugacity

notice that p is replaced with f in the real gas function.

fugacity is a measure of deviation of real gas from the ideal gas model.

Title: Re:Fugacity
Post by: Mitch on August 09, 2005, 03:14:19 PM

Basically, its how much the data needs to be "fudged" in order replicate theory.

Title: Re:Fugacity
Post by: ppithermo on September 12, 2005, 05:42:55 PM

 ;D
Fugacity has the dimension of a pressure.

the ratio of the fugacity  to the pressure is the fugacity coefficient.

It gives a measure of "how much" a gas deviates from an ideal gas.

For an ideal gas, fugacity and pressure are identical