Change in internal energy in air

[S1CkFiSh]

If we apply 300 kJ of heat to 2500 moles of air at constant pressure, what is the change in internal energy?

So far i think I use the equation: (f/x)nkT, but I don't know how to calculate the degrees of freedom and whether I do or not, and whether or not to calculate the number of moles by n=2500/6.022 x 10^23 (avogadro's constant), or if I just plug 2500 moles into n?

 

[Andrew Mason]

If we apply 300 kJ of heat to 2500 moles of air at constant pressure, what is the change in internal energy?

So far i think I use the equation: (f/x)nkT, but I don't know how to calculate the degrees of freedom and whether I do or not, and whether or not to calculate the number of moles by n=2500/6.022 x 10^23 (avogadro's constant), or if I just plug 2500 moles into n?

Look up the Cp for air. It consists mainly of diatomic molecules (N2, O2), if you want to figure it out.

AM

 

[S1CkFiSh]

ok, thank you very much its appreciated