D$6*.$ A coal has the following composition on a dry basis:$-$

$($a$)$ Determine the amount of air required for complete combustion of $100$

$kg$ of coal

$($b$)$ Calculate the composition of the flue gas on a dry basis, and

$($Ans: $($a$)$ air $=39\mathrm{.}04$kmol $($b$)C{O}_2=19\mathrm{.}31$mol$\%,S{O}_2=0\mathrm{.}41$mol$\%,N_2=$

$80\mathrm{.}28$mol$\%$