Question #44829

The chemoselective reduction of a keto-ester by a sterically hindered borohydride reagent proceeds via two competing, irreversible parallel pathways:

Pathway K (Ketone reduction): $A_K = 1.0 \times 10^6 \text{ M}^{-1}\text{s}^{-1}$, $E_{a,K} = 30.0 \text{ kJ mol}^{-1}$ Pathway E (Ester reduction): $A_E = 1.0 \times 10^{10} \text{ M}^{-1}\text{s}^{-1}$, $E_{a,E} = 52.9 \text{ kJ mol}^{-1}$

(Assume $R = 8.3 \text{ J K}^{-1}\text{mol}^{-1}$ and $\ln 10 = 2.3$)

Determine the temperature $T_{eq}$ at which the initial rates of both pathways are equal, and identify the type of reaction control governing the major product formation at $T = 500 \text{ K}$.