This preview shows pages 1–5. Sign up to view the full content.
Lecture No. 6
1
UNIVERSITY
OF
FLORIDA
Thermodynamics
What do we do if gases
cannot
be treated as ideal?
We use a “fudge factor” to make it work.
We call this factor the compressibility factor, z
The equation of state becomes:
Pv = zRT
Where z = v
actual
/v
ideal
,
z =1 for an ideal gas.
So how do we find the factor z?
Experimentally?
See section 3.7 of your text.
This preview has intentionally blurred sections. Sign up to view the full version.
View Full Document Lecture No. 6
2
UNIVERSITY
OF
FLORIDA
Thermodynamics
We use the concept of “reduced pressures” and “reduced
temperatures” to model compressibility factors.
P
r
= P/P
critical
and
T
r
= T/T
critical
Note: use absolute pressure and absolute temperatures
Through experimental observation, we have noted that the z
factor for all gases is approximately the same for the same
reduced pressure and temperature.
This is called the
“principle of corresponding states.”
See the figures in your text for this correlation.
Your text
emphasizes the use of fig. D.1 based on the work of Lee and
Kesler.
The next fig. is based on Nelson and Olbert’s work.
Lecture No. 6
3
UNIVERSITY
OF
FLORIDA
This preview has intentionally blurred sections. Sign up to view the full version.
View Full Document Lecture No. 6
This is the end of the preview. Sign up
to
access the rest of the document.
This note was uploaded on 08/03/2011 for the course EML 3100 taught by Professor Sherif during the Summer '08 term at University of Florida.
 Summer '08
 Sherif

Click to edit the document details