We want to find the change in u for carbon dioxide between 600 K and 1200 K.
a. Find it from a constant Cv0 from Table A.5.
b. Find it from a Cv0 evaluated from the equation in Table A.6. at the average T.
c. Find it from the values of u listed in Table A.8.
TABLE A.5
Properties of Various Ideal Gases at 25°C, 100 kPa*(SI Units)
Gas 
ChemicalFormula 
Molecular Mass(kg/kmol) 
R(kJ/kgK) 
ρ (kg/m3) 
Cp0(kJ/kgK) 
Cv0(kJ/kgK) 

Steam 
H2O 
18.015 
0.4615 
0.0231 
1.872 
1.410 
1.327 
Acetylene 
C2H2 
26.038 
0.3193 
1.05 
1.699 
1.380 
1.231 
Air 
— 
28.97 
0.287 
1.169 
1.004 
0.717 
1.400 
Ammonia 
NH3 
17.031 
0.4882 
0.694 
2.130 
1.642 
1.297 
Argon 
Ar 
39.948 
0.2081 
1.613 
0.520 
0.312 
1.667 
Butane 
C4H10 
58.124 
0.1430 
2.407 
1.716 
1.573 
1.091 
Carton dioxide 
CO2 
44.01 
0.1889 
1.775 
0.842 
0.653 
1.289 
Carton monoxide 
CO 
28.01 
0.2968 
1.13 
1.041 
0.744 
1.399 
Ethane 
C2H6 
30.07 
0.2765 
1.222 
1.766 
1.490 
1.186 
Ethanol 
Solution 130HP
Part (a)
Step 1 of 6:
We are going to find the change in the internal energy of Carbon dioxide gas for constant specific heat found in the table A.5.
The temperature T1 = 600 K
The temperature T2 = 1200 K
The value of specific heat at constant volume from the table (Cv0) = 0.653 kJ/kg.K
The change in the internal energy is given by
Inserting the values
The change in the internal energy is 391.8 kJ/kg.K.
Part (b)
Step 2 of 6:
We are going to find the specific heat from the equation given in the table A.6. The temperature is the average temperature from the part (a).
The temperature Tave
The average temperature is 900 K.
The equation for Cv0 is given by
Step 2 of 6:
The value θ is expressed as
The values of C0, C1, C2, and C3 are taken from the table A.6
C0 = 0.45
C1 = 1.67
C2 = 1.27
C3 = 0.39
From the table A.5, The gas constant for CO2 (R) = 0.1889 kJ/kg.K
Step 3 of 6:
Putting the numerical values in the equation (2)
The specific heat for constant volume is given by