Question

The activation energy of a reaction is zero. The rate constant for the reaction _________.

• A. decreases with decrease of temperature
• B. increases with increase of temperature
• C. decreases with increase of temperature
• D. is nearly independent of temperature

Answer 1

The correct option is D is nearly independent of temperature

Accordingly to Arrhenius Rate Equation:

$k=A{e}^{-E_a/RT}$

where $E_a,A,R,T,k$ are Activation Energy, Pre-exponential Factor, Ideal Gas Constant, Temperature and Rate constant of reaction respectively.

According to question, $E_a$ = 0;

then, rate constant = $A{e}^{-}0/RT$ = $A$ (if T>0 )

This means that rate constant of reaction does notv ary with temperature if temperature is greater than 0 K. And Temperature near to 0 K is nearly impossible to be attained.

Hence, Option $D$ is the correct answer.