Question

The rate constant, the activation energy and the Arrhenius parameter of a chemical reaction at $ 25^{\circ}C $ are $ 3.0 \times 10^{-4} \, s^{-1} $ , $ 104.4 \, kJ \, mol^{-1} $ and $ 6.0 \times 10^{14} \, s^{-1} $ , respectively.
The value of the rate constant at $ T \rightarrow \infty $ is

• A. $ 2.0 \times 10^{18} \, s^{-1} $
• B. $ 6.0 \times 10^{14} \, s^{-1} $
• C. $ 3.6 \times 10^{30} \, s^{-1} $
• D. Infinity

Answer 1

Answer: (B)

Effect of temperature on the rate of reaction hence, rate constant $k$, can be calculated by using Arrhenius equation which is $K=Ae^{-E_{a}/RT}$
given : $A= 6.0\times 10^{-14}\,s^{-1}$
$E_{a}=104.4\,KJ\,mol^{-1}$
$T=\infty $
$\because K=e^{-E_{a}/ RT}$
or $log\,K=log \,A-\frac{E_{a}}{2.303\,RT}$
At $T=\infty$
$log\, k - log\, A+\frac{E_{a}}{2.303\,R\times100}$
$log\,k=log\, A+0$
$log\,k=log\,6\times10^{14}$
$K=6\times10^{14}s^{-1}$