The reaction of cyclopentene with H₂ and a Pd catalyst is a hydrogenation reaction. Here's the equation:

Cyclopentene + H₂ → Cyclopentane

In more detail:

* Reactants:

* Cyclopentene: A cyclic alkene with the formula C₅H₈

* Hydrogen gas (H₂): The source of hydrogen atoms

* Catalyst: Palladium (Pd): A transition metal that facilitates the reaction by providing a surface for the reactants to bind to and interact.

* Product: Cyclopentane: A cyclic alkane with the formula C₅H₁₀

Mechanism:

1. Adsorption: Both cyclopentene and hydrogen molecules adsorb onto the surface of the palladium catalyst.

2. Hydrogenation: The hydrogen atoms on the catalyst's surface break the double bond in cyclopentene, adding two hydrogen atoms to the molecule.

3. Desorption: Cyclopentane, now saturated, desorbs from the catalyst surface.

Overall: This reaction is a simple addition reaction where the double bond in cyclopentene is broken and replaced with two single bonds to hydrogen atoms, resulting in the formation of cyclopentane.