furnace?

$10.$ A synthesis gas analyzing $6\mathrm{.}4$mol$\%C{O}_2,0\mathrm{.}2$mol$\%O_2,40\mathrm{.}0$mol$\%CO,$ and $50\mathrm{.}8$mol$\%H_2($the balance is $N_2)$ is burned with excess dry air. The problem is to determine the composition of the flue gas. How many degrees of freedom exist in this problem?

$11.$ A coal analyzing $($by weight$)65\mathrm{.}4\%C,5\mathrm{.}3\%H,0\mathrm{.}6\%S,1\mathrm{.}1\%N,18\mathrm{.}5\%O,$ and $9\mathrm{.}1\%$ ash is burned so