Chemistry - Chemical Kinetics Question with Solution | TestHub

The Arrhenius equation describes the temperature dependence of rate constants for both elementary and complex reactions.

The Arrhenius equation is:

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

where:

$k$ is the rate constant

$A$ is the pre-exponential factor (frequency factor)

$E_a$ is the activation energy

$R$ is the ideal gas constant

$T$ is the absolute temperature

Analysis of statements:

A. The Arrhenius equation holds true for both elementary and complex reactions, not just elementary homogenous reactions. So, A is incorrect.

B. The unit of $A$ is the same as the unit of $k$. The unit of $k$ depends on the order of the reaction. For a first-order reaction, $k$ has units of s⁻¹, and so does $A$. So, B is correct.

C. At a given temperature, a low activation energy ($E_a$) means a larger value of $e^{-E_a/RT}$, leading to a larger rate constant ($k$) and thus a faster reaction. So, C is correct.

D. $A$ and $E_a$ are generally considered temperature-independent parameters within a reasonable temperature range. So, D is incorrect.

E. $A$ and $E_a$ are independent parameters. Their interdependence is not implied by $E_a\gg RT$. So, E is incorrect.

Therefore, the correct statements are B and C.