A vessel cortaining a fuel$-$gas mixture at ambient temperature

and pressure had some air keaking into it$.$ A sample of the con$-$

tents showec the following composition by vodume: $C{H}_4$ : $\frac{25}{J}$ ia$,$

$C_2{H}_2$:$5\mathrm{.}0\%,H_2$:$10\mathrm{.}0\%,CO$:$70\%,O_2$:$11\mathrm{.}1\%,$ and $N_2$:$41\mathrm{.}9\%.$

Determine

a$.$ Whether the original fuel contained some nitrogen or not know$-$

Ing that no oxygen was originally present in the fuel

b$.$ The volumetric composition of the original fuel

c$.$ The fuel to air mass ratio as analyzed

d$.$ The rich flammability limit of the fuel

e$.$ 'The relative additional mass of air that needs to leak into the ves$-$

sel to make the contents just flammable

You may assume that Le Chatelier's mixing rule applies, and

the values of the rich flammability limits on volume basis at atmo$-$

spheric temperature and pressure are the following: $C{H}_4$:$15\%,H_2$ :

$75\%,C_2{H}_4$:$15\mathrm{.}0\%,$ and CO $.74\%.($Answer: $4\mathrm{.}44)$