Al₂O₃ was leached with alkali to get X. The solution of X on passing of gas Y, forms Z. X, Y and Z respectively are :

The reaction of NO with N₂O₄ at 250 K gives :

Reaction of an inorganic sulphite X with dilute H₂SO₄ generates compound Y. Reaction of Y with NaOH gives X. Further, the reaction of X with Y and water affords compound Z. Y and Z, respectively, are :

The correct statement with respect to dinitrogen is :