$(1) \,C_2H_{6(g)} $ $\rightleftharpoons$ $ C_2H_{4(g)} + H_{2(g)}$
$(2)\, N_{2(g)} + O_{2(g)} $ $\rightleftharpoons$ $ 2NO_{(g)}$
$(3) \,H_{2(g)} + I_{2(g)} $ $\rightleftharpoons$ $ 2HI_{(g)}$
$NO_{(g)} + \frac{1}{2}{O_2} \rightleftharpoons N{O_2}_{(g)}$
$2N{O_2}_{(g)} \rightleftharpoons 2NO_{(g)} + {O_2}_{(g)}$