The uncatalyzed decomposition of peroxide W₂O₂(g) into O₂(g) and W₂(g) is depicted by the following verbal energy profile at 350 K.
• Energy of W₂O₂(g): 18 kJ mol⁻¹
• Energy of the transition state: 128 kJ mol⁻¹
• Energy of products (W₂(g) + O₂(g)): –34 kJ mol⁻¹
A catalyst is discovered that lowers both the forward and reverse activation energies by 46 kJ mol⁻¹ while leaving all other thermodynamic quantities unchanged.
Answer the questions below.
(a) Calculate the new forward activation energy, Ea,fwd(cat), in kJ mol⁻¹.
(b) Determine the new reverse activation energy, Ea,rev(cat), in kJ mol⁻¹.
(c) Explain why the catalyst alters the rate of both the forward and reverse reactions but has no effect on the enthalpy change, ΔHrxn.
(d) Sketch on labeled axes (energy vs. reaction coordinate) a qualitative comparison of the catalyzed and uncatalyzed pathways, clearly marking all relevant energy differences. Your sketch must be referenced in your explanation but does not need to be to scale.