Question

For each of the following pairs of reaction diagrams, identify which of the pair iscatalyzed:

Short answer

(a) Reaction diagram (b) is a catalyzed reaction.

(b) Reaction diagram (b) is a catalyzed reaction.

Step-by-step solution

Definition of Catalyst

Catalysts are substances which increase the rate of the reaction without getting used up by themselves while decreasing the activation energy of the reaction.

• A catalyst increases the rate of reaction.
• Catalyst accelerates the rate of a reaction by decreasing the activation energy.
• Catalyst is regenerated during the reaction.

(a) Reaction diagram (b) uses a catalyst

• The two reaction diagrams depict the same reaction, one with a catalyst and another without a catalyst.
• We can ignore the energy aspect of the diagram as the catalyst does not involve in affecting the energy of the reactant or product.
• But we can notice a small change in the transition state, which is lower in diagram (b) than in diagram (a).

This indicates the presence of a catalyst in diagram (b).

(b) Reaction diagram (b) uses a catalyst 

• The two reaction diagrams depict the same reaction, one with a catalyst and another without a catalyst.
• We can notice a small change in the transition state, which is lower in diagram (b) than in diagram (a).

This indicates the presence of a catalyst in diagram (b).Thus, the reaction diagram (b) is catalyzed among both pairs of reaction diagrams (a) and (b).