Q$6(20$ points$)$ Ammonia and preheated air are mixed to form a gas containing $10\mathrm{.}0$mole$\%$

$N{H}_3$ at $600C.$ The ammonia enters the gas blending unit at $25C$ at a rate of $520k\frac{g}{h}$ and

heat is lost from the mixer to the environment at a rate of $7\mathrm{.}00kW,$ determine the temperature

to which the air must be preheated. $($see example $8\mathrm{.}3-6$ Energy balance on a waste heater boiler$)$

$(A$:$690C)$ See flow chart below

Basis: