C2h4(g) + h2(g) mc030-1.jpg c2h6(g) which change would likely cause the greatest increase in the rate of the reaction?

The reaction is a hydrogenation reaction of an alkene, and its equation is:
C₂H₄(g) + H₂(g) → C₂H₆(g)
Therefore, this reaction can be sped up just as any other irreversible reaction may have its rate increased, by increasing temperature and pressure to increase the effective collisions of molecules.