Problem $3.(30pts)$ Liquid ethanol $(C_2{H}_{5}OH)$ at $25C,1$atm and a mass flow rate of $0\mathrm{.}015k\frac{g}{s}$ enters a combustor operating at steady state and burns completely with $25\%$ excess air entering at $327C,1$atm. The combustion products exit at $927C.$ Calculate: $($a$)$ the air$-$fuel ratio by mass, the mass flow rate of the air, in $\frac{m^3}{h},$ and $($b$)$ the rate of heat transfer from the furnace, in $k\frac{J}{h}r.$