Given below are certain reactions. Identify the reaction for which $K_p = K_c$.

At $298 \, K$,for which of the following reactions will the value of $\frac{K_p}{K_c}$ be maximum and minimum,respectively?
$(a) N_2O_4 \rightleftharpoons 2NO_2$
$(b) 2SO_2 + O_2 \rightleftharpoons 2SO_3$
$(c) X + Y \rightleftharpoons 4Z$
$(d) A + 3B \rightleftharpoons 7C$

The value of $K_{C}$ for the equilibrium reaction: $CO_{2(g)} + C_{(s)} \rightleftharpoons 2CO_{(g)}$ at $T \ K$ is $0.036$. If the equilibrium concentration of $CO_{2(g)}$ is $0.004 \ M$,the concentration of $CO_{(g)}$ in $mol \ L^{-1}$ is:

For the reaction $C_{(s)} + CO_{2_{(g)}} \rightleftharpoons 2CO_{(g)}$,the partial pressure of $CO_2$ and $CO$ at equilibrium are $4 \ atm$ and $8 \ atm$ respectively. $K_p$ for the reaction is

For the reaction ${H_2}_{(g)} + {I_2}_{(g)} \rightleftharpoons 2HI_{(g)}$ at $721 \ K$,the value of the equilibrium constant $({K_c})$ is $50$. When the equilibrium concentration of both is $0.5 \ M$,the value of ${K_p}$ under the same conditions will be:

For the reaction ${N_2}_{(g)} + 3{H_2}_{(g)} \rightleftharpoons 2{NH_3}_{(g)}$,the equilibrium constant ${K_P}$ is $5.8 \times 10^5$ at $298 \ K$. Calculate the value of the equilibrium constant ${K_C}$ (in $mol^{-2} \ L^2$) at the same temperature.