calculate the enthalpy and entropy of saturated isobutene vapor at 360 k from the following...
DESCRIPTION
Enthalpy and Entropy by Graphical Evaluation of Residual PropertiesTRANSCRIPT
Problem:
Calculate the enthalpy and entropy of saturated isobutene vapor at 360 K from the following information:1. compressibility-factor data for isobutene vapor.2. The vapor pressure of isobutane at 360 K is 15.41 bar.3. and for the ideal gas reference state at 300 K and 1 bar.4. The ideal-gas heat capacity of interest is:
Solution:
Compressibility Factors Z for Isobutane
P (bar)340 K350 K360 K370 K380 K
0.10.99770.997190.997370.997530.99767
0.50.987450.98830.989070.989770.9904
20.958950.962060.964830.96730.96953
40.924220.930690.936350.941320.94574
60.887420.898160.907340.915290.92223
80.845750.862180.875860.887450.89743
100.796590.821170.840770.856950.87061
120.77310.801030.823150.84134
140.755060.785310.80923
15.410.71727
Solving for in every pressure at 360 K:
P (bar) (bar-1)
0(0.031500)
0.10.026300
0.50.021860
20.017585
40.015913
60.015443
80.015518
100.015923
120.016581
140.017496
15.410.018347
*Value(s) in parenthesis are found by extrapolation
Plotting at each pressure:
At bar,
Graphing from 350 K to remove decreasing side:
At bar,
At bar,
At bar,
At bar,
At bar,
At bar,
At bar,
At bar,
Differentiating each trend line equation at and dividing each by corresponding pressure gives:
P (bar) (K-1bar-1)
0(1.757 x 10-4)
0.11.700 x 10-4
0.51.474 x 10-4
21.320 x 10-4
41.342 x 10-4
61.446 x 10-4
81.608 x 10-4
101.838 x 10-4
122.093 x 10-4
142.387 x 10-4
15.41(2.594 x 10-4)
*Value(s) in parenthesis are found by extrapolation
Plotting vs. : ,
Graphing : and
Abellar, Rodgie JohnAssignmentAries, Allen JerryChE Thermodynamics 2Belnas, Katrina LynJanuary 27,2014BSChE-4
20.0175850.03517
20.0160.032
20.01550.031
20.01550.031
20.0160.032
20.0165
20.01750.035
1.410.0183470.025869
Summary: