proportional to $V.$
Adiabatic process
$\mathrm{pV}^{\gamma}=$ constant
$\mathrm{p}\left(\frac{\mathrm{M}}{\rho}\right)^{\gamma}=\mathrm{constant}$
$\mathrm{p} \cdot \mathrm{M}^{\gamma} \cdot \rho^{-\gamma}=$ constant $\quad\left(\mathrm{M}^{\gamma} \text { is constant }\right)$
$\mathrm{p} \cdot \rho^{-\gamma}=$ constant


$V\propto {T^{\frac{2}{3}}}$ $[R = 1.99\ cal/mol-K]$
