${N_2}{O_3}\xrightarrow{{R.T.}}NO + N{O_2}$
$C + {O_2} \to C{O_2};\Delta H = - 393\,J$
$2Zn + {O_2} \to 2ZnO;\Delta H = - 412\,J$
${N_2} + 3{H_2} \longrightarrow NH_3$