Problem: Two insulated tanks are connected by a valve. One tank initially contains $2\mathrm{.}11$ lb of air at $230F,39\mathrm{.}0a,$ and the other contains $1\mathrm{.}90$ lb of air at $95F,25\mathrm{.}4a.$ The valve is opened and the two quantities of air are allowed to mix until equilibrium is attained.

Employing the ideal gas model with $k=1\mathrm{.}220,$ determine:

a$.$ The final temperature, in $F$

b$.$ The final pressure, in psia

c$.$ The amount of entropy produced, in $Bt\frac{u}{}R$

$($hint: because volume and mass are changing, use specific volume$)$