What is the Constant Volume Specific Heat for Diatomic Gases?

[melanie]

Just trying to locate specific heat constants with constant volume (not pressure), any ideas where to find this?

 

[abercrombiems02]

If you have a thermodynamic set of property tables it would be in the column with Cv (v should be a subscript) if you are looking at Cp that is the specific heat at constant pressure. They should be fairly close in most non-extreme conditions so becareful what your looking at

 

[Dr.Brain]

C_p : Specific Heat at constant pressure
C_v : Specific Heat at constant volume

Also C_p - C_v = R

\frac {C_p}{C_v} = lamda

where lamda = 1 + \frac {2}{f}

Where f=degrees of freedon

for monoatomic gas , f=3
for diatomic gas , f=3

You can solve for two expressions at the top to get Cp

BJ

 

[quark]

One correction to Dr.Brain's post. f for diatomic gases is 5

 

[siddharth]

One correction to Dr.Brain's post. f for diatomic gases is 5

And that's only at around room temperature's where the vibrational degree of freedom is absent. At high temperatures, f will be 7 for diatomic gases.