Question

Molar specific heat capacity for a polytropic process

Answer 1

Consider an ideal gas. For a polytropic process we have P V n = c o n s t PVn=const. Different values of n n will represent different processes; for example isobaric ( n = 0 n=0), isothermal ( n = 1 n=1), and isochoric ( n = ∞ n=∞). The Wikipedia article on polytropic processes states that the specific heat for a polytropic process is given by C n = C v γ − n 1 − n Cn=Cvγ−n1−n where γ = C P C v γ=CPCv We can see that this expression for C n Cn reduces to what we expect for the different values of n.. For example if n = 0 n=0 (isobaric) we have C 0 = C v γ 1 = C v C P C v = C P C0=Cvγ1=CvCPCv=CP.