Question
Question: Write the Arrhenius equation and explain the terms involved in it....
Write the Arrhenius equation and explain the terms involved in it.
Solution
The Arrhenius equation was given by a Swedish chemist named Svante Arrhenius (1889). The Arrhenius equation shows that the rate of reaction of the chemical reaction is dependent on the absolute temperature
Complete step by step answer:
Arrhenius equation is defined as the expression which shows the relation among the reaction constant of the chemical reaction, the absolute temperature, and the factor which is represented by A is the pre-exponential factor. It is the frequency of the collision among the particles of the reactant.
The Arrhenius equation is shown below.
k=Ae−Ea/RT
Where,
*k represents the rate constant of the chemical reaction.
*A represents the pre-exponential factor which is the frequency of collisions between the reactant species.
*e represents the base of the natural logarithm.
*Ea represents the activation energy of the chemical reaction.
*R represents the universal gas constant.
*T represents the absolute temperature (in kelvin)
Additional information: The pre-exponential factor A is represented by the equation as shown below.
A=ρZ
Where,
*Z represents the frequency factor
*ρ represents the steric factor
The frequency factor is the frequency of collision and the steric factor is the direction of the molecules.
The value for the pre-exponential factor (A) should be determined experimentally as it is assumed differently for every reaction and is dependent on the reaction’s temperature.
The unit of pre-exponential factor (A) is dependent on the order of the reaction.
Note:
When the activation energy is expressed as the energy required by each reactant molecule, the universal gas constant is replaced by the Boltzmann constant represented bykB in the equation.