Question

Metals (Pt, Pd, and Ni) adsorb dihydrogen on their surfaces and activate H − H bond.
What does this line actually means?

Answer 1

Dear Student,

When a hydrogen molecule attract toward the metal surface through vanderwaal forces and hence adsorbed due to unbalance attractive forces or free valecies on surface of metals. Adsorption of Hydrogen gas on metal surface activate H-H bonds.

The dissociation of H-H bonds require energy which it is derived from its adsorption on the metal surface as when H-H adsorbed on metal surface unbalance force are balanced by H₂​ which in turns activate H-H bond i.e., H-H bonds derive energy which is required for its dissociation.

Regards