Question

A catalyst decrease $E_a$ from 100 kJ $mo{l}^{-1}$ to 80 kJ $mo{l}^{-1}$. At what temperature the rate of reaction in the absence of the catalyst at 500 K will be equal to rate reaction in the presence of the catalyst:

• A. 400 K
• B. 200 K
• C. 625 K
• D. None of these

Answer 1

The correct option is A 400 K

For the same rate,
$k_1=k_2$ ($k=A{e}^{-E_a/RT}$)
$A{e}^{-100/500R}=A{e}^{-80/TR}$
$T=400K$