All Problems

Second law of thermodynamics, entropy

Problem 2.146

One mole of an ideal gas with heat capacity \(C_{V}\) goes through a process in which its entropy \(S\) depends on \(T\) as \(S=\alpha / T,\) where \(\alpha\) is a constant. The gas temperature varies from \(T_{1}\) to \(T_{2} .\) Find: (a) the molar heat capacity of the gas as a function of its temperature; (b) the amount of heat transferred to the gas; (c) the work performed by the gas.

Reveal Answer
 (a) C=α/T (b) Q=αln(T1/T2) (c) A=αln(T1/T2)+CV(T1T2)\text { (a) } C=-\alpha / T \text { (b) } Q=\alpha \ln \left(T_{1} / T_{2}\right) \text { (c) } A=\alpha \ln \left(T_{1} / T_{2}\right)+C_{V}\left(T_{1}-T_{2}\right)