Given the equilibria:
$I: A + 2B \rightleftharpoons C ; K_{eq} = K_1$
$II: C + D \rightleftharpoons 3A ; K_{eq} = K_2$
$III: 6B + D \rightleftharpoons 2C ; K_{eq} = K_3$
Which of the following relations is correct?

For the reversible reaction in equilibrium:
$N_{2(g)} + O_{2(g)} \underset{k_2}{\overset{k_1}{\longleftrightarrow}} 2NO_{(g)}$
Given $C_0 = C e^{-2.1 \times 10^{-3}t}$ for the forward reaction and $C'_0 = C' e^{-4.2 \times 10^{-4}t}$ for the backward reaction,calculate the equilibrium constant $K_c$ for the above reaction.

For the reaction: $HI_{(g)} \rightleftharpoons \frac{1}{2}H_{2(g)} + \frac{1}{2}I_{2(g)}$,the equilibrium constant is $8$. What is the equilibrium constant for the reaction: $H_{2(g)} + I_{2(g)} \rightleftharpoons 2HI_{(g)}$?

For the reaction $A + B \rightleftharpoons C + D$,the equilibrium constant is $10$. If the rate constant for the forward reaction is $203$,what will be the rate constant for the backward reaction?

For the reaction: $H_{2(g)} + CO_{2(g)} \rightleftharpoons CO_{(g)} + H_2O_{(g)}$,if the initial concentration of $[H_2] = [CO_2] = 1 \ M$ and $x \ mol/L$ of hydrogen is consumed at equilibrium,the correct expression for $K_c$ is:

For which of the following reactions is $K_p = K_c$?