Question

If the pre-exponential factor in Arrhenius equation is $1.6 \times 10^{12} s^{-1} $, the value of rate constant at extremely high temperature will be close to

• A. $ 4.2 \times 10^{12} s^{-1} $
• B. $1.6 \times0^1{2} s^{-1} $
• C. $2.4 \times 10^{12} s^{-1} $
• D. $1.2 \times 10^6 s^{-1} $

Answer 1

Answer: (B)

$ k=Ae - \frac {E_a}{RT}$
At extremely high temperature $ T \to \infty $
$\therefore k =Ae \frac{E_a}{R^\infty} \Rightarrow k = Ae^{-0} \Rightarrow k = \frac{A}{e^0}
\Rightarrow k=A $