Five moles of an ideal gas at 1 bar and 298k is expanded

$\mathrm{C}_{\mathrm{v}}\left(\mathrm{T}_{2}-\mathrm{T}_{1}\right)$

$-\mathrm{RT} \ln \mathrm{V}_{2} / \mathrm{V}_{1}$

$-\mathrm{RT}\left(\mathrm{V}_{2}-\mathrm{V}_{1}\right)$

zero