Answer is : 962
Initial pressure of \(\mathrm{N}_{2} \mathrm{O}_{5}\)
\(
=\frac{\frac{37.8}{108} \times 0.082 \times 500}{1}=14.35 \mathrm{bar}
\)
\(
2 \mathrm{~N}_{2} \mathrm{O}_{5} \rightleftharpoons 2 \mathrm{N}_{2} \mathrm{O}_{4}+\mathrm{O}_{2}
\)
\(\mathrm{t}=0\quad 14.35\)
\(t = eq\quad 14.35 - 2P\quad 2P\quad P\)
\(\mathrm{P}_{\text {Total }}\) at \(\mathrm{eqb}=14.35+\mathrm{P}=18.65\)
\(
\mathrm{P}=4.3\)
\(
\mathrm{P}_{\mathrm{N}_{2} \mathrm{O}_{5}}=5.75 \mathrm{bar}\)
\(
\mathrm{P}_{\mathrm{N}_{2} \mathrm{O}_{4}}=8.6 \mathrm{bar}\)
\(
\mathrm{P}_{\mathrm{O}_{2}}=4.3 \mathrm{bar}\)
\(\mathrm{k}_{\mathrm{p}}=\frac{(8.6)^{2} \times(4.3)}{(5.75)^{2}}=9.619=\mathrm{x} \times 10^{-2}\)
\(
\mathrm{x}=961.9 \approx 962\)