Question

Which of the following represents the fraction of molecules with energies equal to or greater than E$_a$?

• A. $\dfrac{E_a}{RT}$
• B. e$^{-E_a/RT}$
• C. e$^{+E_a/RT}$
• D. $+\dfrac{E_a}{RT}$

Hint:

The term e$^{-E_a/RT}$ in the Arrhenius equation gives the fraction of molecules having energy ≥ activation energy.

Answer 1

The Correct Option is B

According to the Maxwell-Boltzmann distribution of molecular energies, the fraction of molecules that possess energy $\geq E_a$ is given by:
Fraction = e$^{-E_a/RT}$
This exponential term decreases with increasing activation energy and increases with increasing temperature.