$(35$ pt$)$ In a theoretical, single stage refrigeration cycle using ammonia, the liquid leaves the

condenser as a saturated liquid at $104$ deg F $.$ The refrigerant leaves the evaporator as a

superheated vapor at $18\mathrm{.}3$ psia and $0$ deg F $.$ The system produces $25$ tons of refrigeration. Assume

isentropic compression. The system is as shown in the figure below.

$1Bt\frac{u}{h}r=0\mathrm{.}0003930Hp.$

$($a$)(10pt)$ Calculate the enthalpy at the state points $1-4.(Bt\frac{u}{l}bm)$

$($b$)(5pt)$ Compute the refrigerant mass flow rate of the system in $1b\frac{m}{h}r.$

$($c$)(5pt)$ Compute the heat rejected in the condenser. $($Btu$/$hr$)$

$($d$)(5$ pt$)$ Compute the work of the compressor $($horsepower$)$

$($e$)(5$ pt$)$ Compute the coefficient of performance of the system.

$($f$)(5pt)$ Compute the horsepower$/$ton of refrigeration.