Question

Which of the following is/are true about the Arrhenius theory?

• A. Reaction can take place only when the reactant molecules collide
• B. It does not explain the temperature dependence of the rate of a chemical reaction
• C. Activated complex formed in the reaction is unstable in nature
• D. Product formed in the reaction will always have lower energy than activation complex

Answer 1

Answer: (A), (C), (D)

Product formed in the reaction will always have lower energy than activation complex

To explain the effect of​ temperature on reaction rate, Arrhenius theory was evolved​. The temperature dependence of the rate of a chemical reaction can be accurately explained by Arrhenius theory.

Arrhenius theory:
For elementary reaction,
$A_2+B_2\to 2AB$
1. Reaction can take place only when a molecule of $A_2$ and a molecule of $B_2$ collide.

2. The collision leads to the formation of an unstable state​ which exists for a very short​ time and gradually leads to the product​ formation. This is called transition state.
The unstable complex at the transition state is called​ Activated complex.

Energy is released when the complex decomposes to form products​.
The final enthalpy of the ​reaction depends upon the nature of reactants and products.​

3. Energy required to form​ the transition state is called activation energy.