$[15$ Pts$]4m4m3m$ room filled with air and is initially at $30C$ and $100$ kPa $.$ The room

is thermally in contact with a cooling system using R$-134$a$,$ which goes between saturated liquid

at $-25C$ and a binary mixture with $90\%$ quality $(x)$ at $-25C.$ Assume the control volume

containing R$-134$a can freely expand and contract without friction. Treat air as an ideal gas.

$($a$)$ How much heat do you have to remove from the room to cool it down

to $25C?$ Assume no air leaves or enters the room. $[5$ Pts$]$

$($b$)$ What is the total mass of R$-134$a in the cooling system? $[7$ Pts$]$

$($c$)$ Draw R$-134$a$`$s thermodynamic process on a $P-v$ diagram. Include

important coordinates and the direction of the process. $[3$ Pts$]$

LOOK UP VALUES IN THE THERMODYNAMICS CHART DO NOT TELL ME TO LOOK