Question

Given the reaction below: N2O4 (g) ⇌ 2 NO2 (g)

Answer 1

N₂O₄ (g) ⇌ 2 NO₂ (g)

Kc = [ NO₂ ]² / [ N₂O₄ ]

4.2 =  [ 0.785 ] [ N₂O₄ ]

[ N₂O₄ ] = 4.2 / 0.785

[N₂O₄ ] = 5.350 M

hope this helps!