One mole of $\mathrm{C}_2 \mathrm{H}_5 \mathrm{OH}(l)$ was completely burnt in oxygen to form $\mathrm{CO}_2(\mathrm{~g})$ and $\mathrm{H}_2 \mathrm{O}(l)$. The standard enthalpy of formation $\left(\Delta_f \mathrm{H}^{\ominus}\right)$ of $\mathrm{C}_2 \mathrm{H}_5 \mathrm{OH}(l), \mathrm{CO}_2(\mathrm{~g})$ and $\mathrm{H}_2 \mathrm{O}(l)$ is $x, y, z \mathrm{~kJ} \mathrm{~mol}^{-1}$ respectively. What is $\Delta_r \mathrm{H}^{\ominus}$ (in $\mathrm{kJ} \mathrm{mol}^{-1}$ ) for this reaction?

• A

  $(2 y+3 z+x)$
• B

  $(2 y-3 z+x)$
• C

  $(x-2 y-3 z)$
• Correct answer
  D

  $(2 y+3 z-x)$

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