C ( s )+2 H_2( g ) → CH_4( g ); Δ H =-74.8 kJ mol^-1 Which of the following diagrams gives an accurate representation of the above reaction? [R →…

$\displaystyle \mathrm{C}(\mathrm{s})+2 \mathrm{H}_2(\mathrm{~g}) \rightarrow \mathrm{CH}_4(\mathrm{~g}) ; \Delta \mathrm{H}=-74.8 \mathrm{~kJ} \mathrm{~mol}^{-1}$ Which of the following diagrams gives an accurate representation of the above reaction? [R → reactants; P → products]