Two parallel, irreversible, first-order decomposition pathways convert reactant R into either P₁ or P₂. The rate constants for each pathway were measured at two different temperatures and are summarized below.
Temperature (K)
kP1 (s−1)
kP2 (s−1)
300 K
1.5 × 10⁻³
4.2 × 10⁻⁴
330 K
4.5 × 10⁻³
2.1 × 10⁻³
Assume Arrhenius behavior with temperature-independent frequency factors.
(a) Determine the activation energy for each pathway. Show all steps in your calculations.
(b) Using your results from part (a), predict the ratio rateP2rateP1 at 350 K.
(c) Identify which product will predominate initially at 350 K and justify your answer based on quantitative evidence.