8.2 Organic chemistry isomerism — Chemistry STD 11 Science — Question

$\left. \begin{gathered}
  {\text{4N}}{{\text{H}}_{3(g)}}{\text{ + 5}}{{\text{O}}_{2(g)}} \to {\text{ 4N}}{{\text{O}}_{(g)}}{\text{ +  6}}{{\text{H}}_{\text{2}}}{{\text{O}}_{{\text{(l)}}}} \hfill \\
  {\text{2N}}{{\text{O}}_{(g)}}{\text{ + }}{{\text{O}}_{2(g)}} \to {\text{2N}}{{\text{O}}_{2(g)}} \hfill \\
  {\text{3N}}{{\text{O}}_{2(g)}}{\text{ +  }}{{\text{H}}_{{\text{ 2}}}}{{\text{O}}_{(l)}} \to {\text{2H N}}{{\text{O}}_{3(aq)}}{\text{ +  N}}{{\text{O}}_{(g)}} \hfill \\ 
\end{gathered}  \right|\begin{array}{*{20}{c}}
  {\Delta H(kJ)} \\ 
  { - 904} \\ 
  { - 112} \\ 
  { - 140} 
\end{array}$

$A + B  \rightleftharpoons  C + D$ is $1 \times 10^{-2}$ at $298\, K$ and is

$2$ at $273\, K$. The chemical process resulting in the formation of $C$ and $D$ is