$[25]$ Butane $(C_4{H}_{10})$ is burned completely $(100\%$ conversion$)$ in a furnace. Pure oxygen is supplied

in excess. An analysis of the stack gas shows the following molar composition: $24\%C{O}_2,6\%CO,$

$37\mathrm{.}5\%H_{2}O,32\mathrm{.}5\%O_2.$

$($a$)[15]$ Draw and label the flowchart with $100mo\frac{l}{h}$ of stack gas as basis and the two chemical

reactions.

$($b$)[15]$ Write down the atomic balances on carbon and oxygen.

$($c$)[10]$ What is the feed butane molar flow rate?

$($d$)[10]$ What is the $\%$ excess oxygen supplied?