QUESTION $1$: A fuel$/$air mixture is being prepared for combustion by mixing the gaseous fuel with compressed air. The product mixture is then sent for combustion. The fuel mixture consists of $80$mol$\%C_2{H}_8$ with the balance $C_4{H}_{10}.$ The air is supplied at a volumetric flowrate of $10m\frac{3}{m}in.$ At a pressure of $2$atm and temperature of $C.$ For $10mo\frac{l}{m}in$ of fuel:

$($a$)$ Carryout a degree of freedom analysis assuming air is an ideal gas.

$($b$)$ Find the composition of the mixed stream.

Hint: When carrying out the DOF analysis consider air as a single component $($since it is not changing in composition$)$ and use the ideal gas law as an additional relationship when carrying out DOF analysis.

QUESTION $2$: The gas mixture in Question $1$ is now ignited using a burner. If there is excess oxygen, the combustion reaction proceeds to completion for both fuels as:

$C_2{H}_8+5O_{2}3C{O}_2+4H_{2}O$

$C_4{H}_{10}+\frac{13}{2}{O}_{2}4C{O}_2+5H_{2}O$

$($a$)$ Draw and label a diagram representing this and carryout a degree of freedom analysis.

$($b$)$ Using the molecular species balance, determine the gas flowrate and composition.