$5($d$)\_$#$2$: A vapor$-$compression refrigeration system circulates Refrigerant $22$ at a rate of $12l\frac{b}{m}in.$ The refrigerant enters the compressor at $-40F,15lb\frac{f}{i}{n}^2,$ and exits at $80lb\frac{f}{i}{n}^2.$ The isentropic compressor efficiency is $67\%.$ There are no appreciable pressure drops as the refrigerant flows through the condenser and evaporator. The refrigerant leaves the condenser at $80lb\frac{f}{i}{n}^2,30F.$ Ignoring heat transfer between the compressor and its surroundings, determine

a$)$ the compressor power, in Btu$/$min$,$ and the refrigeration capacity, in tons. $(4\mathrm{.}89$ tons$)$

b$)$ the coefficient of performance. $(3\mathrm{.}1)$