Chemistry - Chemical Kinetics Question with Solution | TestHub

$k=A{e}^{-E_a/RT}$

(a) If activation energy ($E_a$) increases, the exponent becomes more negative, which means $k$ decreases, and thus the rate decreases.

(b) At a lower temperature, a small increase in $T$ causes a large change in the exponential term, which means $k$ changes more.