All Problems

Kinetic theory of gases. Boltzmanns Law and Maxwell distribution

Problem 2.72

Find the number of degrees of freedom of molecules in a gas whose molar heat capacity (a) at constant pressure is equal to \(C_{p}=29 \mathrm{~J} /(\mathrm{mol} \cdot \mathrm{K})\); (b) is equal to \(C=29 \mathrm{~J} /(\mathrm{mol} \cdot \mathrm{K})\) in the process \(p T=\) const.

Reveal Answer
\[ \text { 2.72. (a) } i=2\left(C_{p} / R-1\right)=5 ; \text { (b) } i=2[C / R+1 /(n-1)]= \] \(=3,\) where \(n=1 / 2\) is the polytropic index.