The figure below is *verbally* described. Imagine two potential-energy curves, both starting from the same reactant energy of 50 kJ mol⁻¹ and ending at the same product energy of –30 kJ mol⁻¹.
Uncatalyzed path: a single peak at 200 kJ mol⁻¹.
Catalyzed path: first peak at 110 kJ mol⁻¹, forms an intermediate at 20 kJ mol⁻¹, then a second peak at 120 kJ mol⁻¹ before falling to products.
Answer the following.
(a) Calculate the overall enthalpy change, ΔH, for the reaction.
(b) Identify which elementary step is rate-determining for the catalyzed pathway and justify your answer using the information given.
(c) Explain why the catalyst is not consumed during the course of the reaction even though it participates in the rate-determining step.
(d) Compare the values of ΔH for the catalyzed and uncatalyzed pathways and account for any similarities or differences.