Dinitrogentetraoxide Partially Decomposes into Nitrogen Dioxide

Dinitrogentetraoxide partially decomposes into nitrogen dioxide.A 1.00-L flask is charged with of N₂O₄.At equilibrium at 373 K,0.0055 mol of N₂O₄ remains.K_eq for this reaction is ________.

A) 2.2 × 10^-4
B) 13
C) 0.22
D) 0.87
E) 0.022