Question $3$

$3\mathrm{.}1.$ Air is heated from $25C$ to $150C$ prior to entering a combustions furnace. The change in specific enthalpy associated with this transition is $3640\frac{J}{m}ol.$ The flow rate of air at the heater outlet is $125\frac{m^3}{m}in$ and the air pressure at this point is $122$kPa absolute$.$

$3\mathrm{.}1\mathrm{.}1.$ Calculate the heat requirement in $kW,$ assuming ideal gas behavior and that kinetic and potential energy changes from the heater inlet to the outlet are negligible.

$3\mathrm{.}1\mathrm{.}2.$ Would the value of $E_k$ be positive or negative, or would you need more information to be to tell the latter, what additional information would be needed?

$3\mathrm{.}2.$ Oxygen at $150K$ and $41\mathrm{.}64$atm has a tabulated specific volume of $4\mathrm{.}684c\frac{m^3}{g}$ and a specific internal energy of $1706\frac{J}{m}ol.$ Calculate the specific enthalpy of $O_2$ in this state.

Take $R=\frac{8\mathrm{.}314\frac{J}{\text{m}\text{o}\text{l}\text{.}K}}{0\mathrm{.}08206(L)\frac{\text{a}\text{t}\text{m}}{\text{m}\text{o}\text{l}\text{.}K}}$

$[20$ Marks$]$