Chemical Equilibrium

37.8gN2O5 was taken in a 1 L reaction vessel and allowed to undergo the following reaction at 500 K
2N2O5(g)⇌2N2O4(g)+O2(g)
The total pressure at equilibrium was found to be 18.65 bar.Then, Kp= ______ ×10−2 [nearest integer]Assume N2O5 to behave ideally under these conditions.
Given : R=0.082barL‌mol‌−1K−1