The equation that represents the water-gas shift reaction is [JEE Main 2020, 5 Sep (Shift 1)]

\begin{equation}
\mathrm{CO}(\mathrm{g})+\mathrm{H}_2 \mathrm{O}(\mathrm{g}) \xrightarrow[\text { Catalyst }]{673 \mathrm{~K}} \mathrm{CO}_2(\mathrm{~g})+\mathrm{H}_2(\mathrm{~g})
\end{equation}

\( \mathrm{C}(\mathrm{s})+\mathrm{H}_{2} \mathrm{O}(\mathrm{g}) \stackrel{1270 \mathrm{~K}}{\longrightarrow} \mathrm{CO}(\mathrm{g})+\mathrm{H}_{2}(\mathrm{~g}) \)

\( 2 \mathrm{C}(\mathrm{s})+\mathrm{O}_{2}(\mathrm{~g})+4 \mathrm{~N}_{2} \stackrel{1273 \mathrm{~K}}{\longrightarrow} 2 \mathrm{CO}(\mathrm{g})+4 \mathrm{~N}_{2}(\mathrm{~g}) \)

\begin{equation}
\mathrm{CH}_4(\mathrm{~g})+\mathrm{H}_2 \mathrm{O}(\mathrm{g}) \xrightarrow[N i]{1270 \mathrm{~K}} \mathrm{CO}(\mathrm{g})+3 \mathrm{H}_2(\mathrm{~g})
\end{equation}