Reactivity order in hydrogenation reaction of but-2-yne and butene isomers
Monosubstituted alkene is more reactive than disubstituted because directly attached alkyl groups stabilize the system. Therefore 1 butene is more reactive.

Cis is more reactive than trans because Cis compounds are unstable. As they have similar groups on same side, it results in stearic crowding.

Thirdly, conjugated dienes are very stable beacuse they are resonance stabilized.

Thus order will be
1 butene will be most reactive, then Cis, then trans and then 1,3 butadiene..