P$4-7$ B OEQ $($Old Exam Question$).$ Consider the following elementary gas$-$phase reversible reaction to be carried out isothermally with no pressure drop and for an equal molar feed of A and B with $C_{AO}=2\mathrm{.}0mo\frac{l}{d}{m}^3.$

$2A+BC$

a$.$ What is the concentration of $B$ initially? $d{m}^3)$

b$.$ What is the limiting reactant?

c$.$ What is the exit concentration of $B$ when the conversion of $A$ is $25\%?C_B=,(mo\frac{l}{d}{m}^3)$

d$.$ Write $-r_A$ solely as a function of conversion $($i$.$e$.,$ evaluating all symbols$)$ when the reaction is an elementary, reversible, gas$-$phase, isothermal reaction with no pressure drop with an equal molar feed and with $C_{A0}=2\mathrm{.}0mo\frac{l}{?}d{m}^3,k_A=2d\frac{m^6}{m}o{l}^2*s,$ and $K_C=0\mathrm{.}5$ all in proper units $r_A=$