For a solution-phase oxidation

CHEMISTRY · Multi-part · AP · Chemistry · Kinetics · Kinetics

Problem

For a solution-phase oxidation, the potential-energy diagram is described numerically below. Energies are given relative to the reactants, whose energy is set to 0 kJ mol−10\,\text{kJ mol}^{-1}. Step 1: Transition state at +55 kJ mol−1+55\,\text{kJ mol}^{-1} → Intermediate A at −15 kJ mol−1-15\,\text{kJ mol}^{-1} Step 2: Transition state at +85 kJ mol−1+85\,\text{kJ mol}^{-1} → Intermediate B at −10 kJ mol−1-10\,\text{kJ mol}^{-1} Step 3: Transition state at +45 kJ mol−1+45\,\text{kJ mol}^{-1} → Products at −70 kJ mol−1-70\,\text{kJ mol}^{-1} Assume each step is elementary. (a) Calculate the enthalpy change, ΔH\Delta H, for each of the three elementary steps. (b) Determine the overall ΔH\Delta H for the reaction. (c) Identify the activation energy, EaE_{a}, for each elementary step and state which step is the slowest at a fixed temperature. (d) Using your answers to parts (b) and (c), decide whether the forward or the reverse overall reaction would be more sensitive to a temperature increase. Justify your reasoning qualitatively, referring to the energy profile.

Related theory

Browse the problem library