Q.
An ideal gas with heat capacity at constant volume Cv undergoes a quasistatic process described by pVα in a p−V diagram, where a is a constant. The heat capacity of the gas during this process is given by
Process equation is pVα=constant (k) ⇒p=Vαk
Work done by the gas in given process is ΔW∫ViVfpdV =∫ViVfVαkdV=[1−αkV1−α]Vf =[1−αpV]ViVf=1−αp(Vf−Vi) =1−αpΔV=1−αnRΔT
The change of internal energy of gas inthis process will be ΔU=CVΔT
And if ΔQ is heat supplied to the gasthen, ΔQ=cΔT
Now, by first law of thermodynamics, wehave ΔQ=ΔU+ΔW ⇒CΔT=CVΔT+1−αnRΔT
Heat capacity of the gas is ⇒C=CV+1−αnR