How do you find the frequency factor from an Arrhenius plot?
The Arrhenius equation is k=Ae-Ea/RT, where k is the reaction rate constant, A is a constant which represents a frequency factor for the process, Ea is the activation energy for the reaction, R is the gas constant, and T is the temperature in Kelvins.
What is the frequency factor in the Arrhenius equation?
The pre-exponential factor (A) is an important component of the Arrhenius equation, which was formulated by the Swedish chemist Svante Arrhenius in 1889. The pre-exponential factor is also known as the frequency factor, and represents the frequency of collisions between reactant molecules at a standard concentration.
What is the frequency factor value?
The frequency factor is used to describe the rate of molecular collisions that occur in the chemical reaction. You can use it to measure the frequency of the molecular collisions that have the proper orientation between particles and appropriate temperature so that the reaction can occur.
What is a frequency factor or pre-exponential factor?
The pre-exponential factor, A, is a constant that can be derived experimentally or numerically. It is also called the frequency factor and describes the number of times two molecules collide. In empirical settings, the pre-exponential factor is considered constant.
What is Arrhenius equation used for?
Arrhenius equation, mathematical expression that describes the effect of temperature on the velocity of a chemical reaction, the basis of all predictive expressions used for calculating reaction-rate constants.
How is EA calculated?
Solution
- Step 1: Convert temperatures from degrees Celsius to Kelvin. T = degrees Celsius + 273.15. T1 = 3 + 273.15.
- Step 2 – Find Ea ln(k2/k1) = Ea/R x (1/T1 – 1/T2) ln(7.1 x 10-2/8.9 x 10-3) = Ea/8.3145 J/K·mol x (1/276.15 K – 1/308.15 K)
- Answer: The activation energy for this reaction is 4.59 x 104 J/mol or 45.9 kJ/mol.
