Identify the reaction for which $\Delta H \neq \Delta E$ :

• A

  $\mathrm{S}$ (rhombic) $+\mathrm{O}_2(\mathrm{~g}) \longrightarrow \mathrm{SO}_2(g)$
• B

  $\mathrm{N}_2(\mathrm{~g})+\mathrm{O}_2(\mathrm{~g}) \longrightarrow 2 \mathrm{NO}(\mathrm{g})$
• C

  $\mathrm{H}_2(g)+\mathrm{Cl}_2(g) \longrightarrow 2 \mathrm{HCl}(g)$
• Correct answer
  D

  $\mathrm{CO}(g)+\frac{1}{2} \mathrm{O}_2(g) \longrightarrow \mathrm{CO}_2(g)$

Hence, the correct answer is option: 'D'.