$($Elliott P$2\mathrm{.}12)$ In the following take $Cv=5$ and $Cp=7ca\frac{l}{m}ol-K$ for nitrogen

gas:

$($a$)$ Five moles of nitrogen at $100C$ is contained in a rigid vessel. How much

heat must be added to the system to raise its temperature to $300C$ if the

vessel has a negligible heat capacity? $($ANS$.5000$cal $)$

$($b$)$ Five moles of nitrogen at $300C$ is contained in a piston$/$cylinder ar$-$

rangement. How much heat must be extracted from this system, which

is kept at constant pressure, to cool it to $100C$ if the heat capacity of the

piston and cylinder is neglected? $($ANS$.7000$cal $)$