Question

If the activation energy of a reaction is 80.9 kJ $mo{l}^{-1}$, the fraction of molecules at 700 K, having enough energy to react to form products is $e^{-x}$. The value of x is_____. (Rounded off to the nearest integer)

[Use $R=8.31J{K}^{-1}mo{l}^{-1}$ ]

Answer 1

$E_a=80.9kJ/mol$
Fraction of molecules able to cross energy barrier = $e^{-Ea/RT}=e^{-x}$

$x=\frac{E_a}{RT}=\frac{80.9\times 1000}{8.31\times 700}=13.91$

$x\approx 14$