Question $3$

A volume of air $($ideal gas$)$ of $15$ liters at atmospheric pressure $P_1=1013$hPa$(1,{01310}^5(Pa))$ and at $T_1=15C$ undergoes the following two transformations:

Transformation $1-2$: isochoric compression. The air is heated to temperature $T_2$ untill is pressure is equal to $P_2=4^{**}{P}_1.$

Transformation $2-3$: isobaric expansion. The air is heated until its temperature reaches $T{I}^{?}=950C.$

We given for the air :

Mw$=29$g$$mol$^-1,$R$=8\mathrm{.}32$j$$mol$^-1$kg$-1$ and Cv$=708$J$$k$^-1$kg$-1.$

$1-$ represent the $2$ transformations in clapeyron coordinaties $.$

$2-$what is the temperature T$2$ reached by the air at the end of transformation $1-2?$

$3-$ calculate the mass m of air and deduce the change in internal energy of the air in the transformation $1-2.$

$4-$ what is the volume occupied by air at the end of transformation $2-3?$

$5-$ calculate the change in internal energy of air in transformation $2-3.$