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.

The Arrhenius equation describes the relation between the rate of reaction and temperature for many physical and chemical reactions. A common form of the equation is [9]: (6.10) where k=kinetic reaction rate, k0=rate constant, E=activation energy, R=universal gas constant and T=absolute temperature.

The Arrhenius equation indicates the relationship between the reaction temperature (T) and the reaction rate constant (k) in Equation 1, where A represents the pre- exponential factor, Ea is the apparent activation energy, T and R stand for absolute temperature and universal gas constant, respectively.

The Arrhenius equation allows us to calculate activation energies if the rate constant is known, or vice versa. As well, it mathematically expresses the relationships we established earlier: as activation energy term Ea increases, the rate constant k decreases and therefore the rate of reaction decreases.

Arrhenius theory, theory, introduced in 1887 by the Swedish scientist Svante Arrhenius, that acids are substances that dissociate in water to yield electrically charged atoms or molecules, called ions, one of which is a hydrogen ion (H+), and that bases ionize in water to yield hydroxide ions (OH−).

Solutions

1. Use the Arrhenius Equation: k=Ae−Ea/RT. k is the rate constant, A is the pre-exponential factor, T is temperature and R is gas constant (8.314 J/molK)
2. Use the equation: ln(k1k2)=−EaR(1T1−1T2)
3. Use the equation ΔG=ΔH−TΔS.
4. Use the equation lnk=lnA−EaRT to calculate the activation energy of the forward reaction.
5. No.

The value of the slope (m) is equal to -Ea/R where R is a constant equal to 8.314 J/mol-K. The activation energy can also be found algebraically by substituting two rate constants (k1, k2) and the two corresponding reaction temperatures (T1, T2) into the Arrhenius Equation (2).

Notice that when the Arrhenius equation is rearranged as above it is a linear equation with the form y = mx + b; y is ln(k), x is 1/T, and m is -Ea/R. The activation energy for the reaction can be determined by finding the slope of the line. Which R?…

The equation is commonly given in the form of an exponential function, k = Aexp(−E/RT), and it predicts that a small increase in reaction temperature will produce a marked increase in the magnitude of the reaction-rate constant. The Arrhenius equation was originally formulated by J.J.

The Arrhenius equation introduces the relationships between rate and A, E a, and T, where A is the pre-exponential factor, E a is the activation energy, and T is the temperature. The pre-exponential factor, A, is a constant that can be derived experimentally or numerically.

Arrhenius’ equation gives the dependence of the rate constant of a chemical reaction on the absolute temperature, a pre-exponential factor and other constants of the reaction.

The equation was first proposed by Svante Arrhenius in 1884. Five years later, in 1889, Dutch chemist J. H. van ‘t Hoff provided physical justification and interpretation for it. The equation combines the concepts of activation energy and the Boltzmann distribution law into one of the most important relationships in physical chemistry:

Because the pre-exponential factor depends on frequency of collisions, it is related to collision theory and transition state theory. The Arrhenius equation introduces the relationships between rate and A, E a, and T, where A is the pre-exponential factor, E a is the activation energy, and T is the temperature.