Methane and oxygen react in the presence of a catalyst to form formaldehyde. In a parallel reaction,

methane is oxidized to carbon dioxide and water.

$C{H}_4(g)+O_2(g)$HCHO$(g)+H_{2}O(g)$

$C{H}_4(g)+2O_2(g)C{O}_2(g)+2H_{2}O(g)$

a$)$ Methane is fed with $40\%$ excess air at $50C$ and $40\%$ relative humidity. If the mole fraction of $C{O}_2$ in

the effluent gases is $0\mathrm{.}15$ mol $C\frac{O_2}{m}ol$ gas, and there is no remaining $C{H}_4,$ determine the composition of

the reaction product.