At $\mathrm{T}(\mathrm{K})$, consider the following gaseous reaction, which is in equilibrium. $\mathrm{N}_2 \mathrm{O}_5 \rightleftharpoons 2 \mathrm{NO}_2+\frac{1}{2} \mathrm{O}_2$ What is the fraction of $\mathrm{N}_2 \mathrm{O}_5$ decomposed at constant volume and temperature, if the initial pressure is 300 mm Hg and pressure at equilibrium is 480 mm Hg ? (Assume all gases as ideal)

• A

  $0.2$
• B

  $0.6$
• Correct answer
  C

  $0.4$
• D

  $0.8$

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