The equilibrium constant, k c, for the reaction n2o4 (g) ⇄ 2no2 (g) is 0.211 at 100°c. if the equilibrium concentration of n2o4 is 0.00251 m, calculate the equilibrium concentration of no2.

Answer is: 0.0213M.

Reaction: N₂O₄ (g) ↔ 2NO₂ (g).

Kc = 0,211 at 100°C.

Kc - equilibrium constant.

c (N₂O₄) = [N₂O₄] = 0,00251M.

c (NO₂) = [NO₂] = ?

Kc = [NO₂]² / [N₂O₄]

[NO₂]² = Kc · [N₂O₄]

[NO₂] = √ (Kc · [N₂O₄ ])

[NO₂] = √ (0.211 · 0.00215M)

[NO₂] = 0.0213M.