18 CHEMICAL ENGINEERING VOLUME 1 SOLUTIONS
ideal gas is given by equation 2.25:
CvdTDPdvDdU.
PDRT/Mvand hence: dT/TD R/MCv dv/v
By definition: DCp/CvandCpDCvCR/M(from equation 2.27)
∴ R/MCvD1anddT/TD
1
dv/v
Integrating between conditions 1 and 2 gives:
ln
T 2 /T 1 D
1 ln v 2 /v 1 or
T 2 /T 1 D v 2 /v 1 ^1
P 1 v 1 /T 1 DP 2 v 2 /T 2 and hencev 1 /v 2 D
P 2 /P 1
T 1 /T 2
and:
T 2 /T 1 D
P 2 /P 1
^1 /
Using the symbols given, the final temperature,T 2 DT
P/P 0
^1 /