Question

The rate constant, the activation energy and the Arrhenius parameter of a chemical reaction at $25°C$ are $3.0\times 10^{-4}{s}^{-}$ , $104.4kJmo{l}^{-1}$ and $6\times 10^{14}{s}^{-1}$ respectively. The value of the rate constant at temperature $T=\in fty$ is

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

Answer 1

Answer: (B)

$k=A{e}^{-Ea/RT}$ (Arehenius equation)
when $T\to \in fty$
$=A\times \frac{1}{e^{\frac{E_a}{RT}}}T\to \infty =\frac{1}{T}=0\to \frac{Ea}{RT}=0e^0=1Puttheabovevalueingivenequation=A\times \frac{1}{e^{\frac{E_a}{RT}}}K=ASo,A=6.0\times 10^{14}s-1$
It means at high temperature low activation energy favour larger rate constant.