Concept:A catalyst speeds up a reaction by lowering the activation energy needed for the reaction to occur.
Explanation:Nickel is used as a catalyst in the hydrogenation of alkenes.
A catalyst provides an alternative reaction pathway with a lower activation energy
(Ea).
Catalysts do not increase the yield of the product or change the enthalpy of the reaction.
They also do not prevent the reverse reaction from occurring; they simply help the reaction reach equilibrium faster.
By lowering the activation energy, more reactant particles have enough energy to react successfully.
This makes the hydrogenation process faster without being consumed during the reaction.
Therefore, nickel is used because it lowers the activation energy of the reaction.
Answer:B. lowers the activation energy of the reaction