Question

The activation energy for a chemical reaction depends upon:
A.Temperature
B.Nature of reacting species
C.Concentration of the reacting species
D.Collision frequency

Answer 1

Hint: Activation Energy: Activation energy is a physical quantity that can be understood as the minimum amount of energy that must be provided to a system for the reaction in the system to start. To put it in simpler terms, it is the energy push required to push the reaction in the forward direction.

Complete Step-by-Step Answer:

Before we move forward with the solution of the given question, let us first understand some important basic concepts.
Activation energy is basically the potential barrier that separates the minima of the potential energy surface which pertains to the initial and the final thermodynamic state.
Activation energy is calculated using an equation known as Arrhenius’ equation. The mathematical representation of this equation can be given as:
 \[k = Ae\dfrac{{ - {E_a}}}{{(RT)}}\]
Where k is reaction rate coefficient, A is a pre – exponential factor, R is the gas constant and T is the absolute temperature. This equation can be rewritten as:
 \[\ln (\dfrac{k}{A}) = - \dfrac{{{E_a}}}{{RT}}\]
 \[{E_a} = - \ln (\dfrac{k}{A}).RT\]
Hence, we can see that the activation energy is directly dependent on the temperature of the system.

Hence, Option A is the correct option

Note: High activation energy can be understood as higher energy required to achieve a successful collision between the particles. A good example for this could be combustion. Even though combustion is an exothermic reaction, because of the high activation energy it requires heat. The particle gains enough energy from heat to overcome the barrier of activation energy.