All Problems

First law of thermodynamics, heat capacity

Problem 2.45

Find the molar heat capacity of an ideal gas in a polytropic process \(p V^{n}=\) const if the adiabatic exponent of the gas is equal to \gamma. At what values of the polytropic constant \(n\) will the heat capacity of the gas be negative?

Reveal Answer
Cn=R(nγ)/(n1)(γ1);Cn<0 for 1<n<γC_{n}=R(n-\gamma) /(n-1)(\gamma-1) ; C_{n}<0 \text { for } 1<n<\gamma