What is the specific enthalpy change when oxygen, which may be considered a perfect gas of molecular weight 32 is heated from 20°C to 50°C? For oxygen, c/c = 1.4. Ř= 8.3143 ki/kmol.

Respuesta :

Answer:

h=27.15 KJ/kg

Explanation:

We know that ,Enthalpy of perfect gas depends only on temperature it did not depends on the volume and pressure.But on the other hand enthalpy of real gas depends on the temperature and pressure.

So specific enthalpy(h) is given as follows

[tex]h=C_p\Delta T[/tex]

[tex]\dfrac{C_p}{C_v}=1.4[/tex]

[tex]C_p-C_v=R[/tex]

For oxygen

[tex]R=\dfrac{8.314}{32} \frac{KJ}{Kg-k}[/tex]

[tex]R=0.259\frac{KJ}{Kg-k}[/tex]

[tex]C_p=1.4C_v[/tex]

From above

[tex]C_p=0.905\frac{KJ}{Kg}[/tex]

So

[tex]h=0.905(50-20)[/tex]

h=27.15 KJ/kg