Arrheniusrelationen

The Arrhenius relation, also known as the Arrhenius equation, describes the temperature dependence of reaction rates. It was proposed by the Swedish chemist Svante Arrhenius in 1889. The equation quantifies how the rate of a chemical reaction increases with temperature.

The relation is typically expressed as: k = A * exp(-Ea / (R * T)). In this formula, k represents the rate constant of the reaction, which is a measure of how fast the reaction proceeds. The symbol A is the pre-exponential factor, also known as the frequency factor. It relates to the frequency of collisions between reactant molecules and the orientation of these collisions. Ea stands for the activation energy, the minimum energy required for a reaction to occur. R is the ideal gas constant, and T is the absolute temperature in Kelvin.

The exponential term, exp(-Ea / (R * T)), signifies the fraction of molecules that possess sufficient energy to overcome the activation energy barrier at a given temperature. As temperature T increases, the exponent becomes less negative, leading to a larger value for the exponential term and thus a higher rate constant k. Conversely, a decrease in temperature results in a lower rate constant. The activation energy Ea is a crucial parameter; a higher activation energy means the reaction rate is more sensitive to temperature changes. The Arrhenius relation is a fundamental concept in chemical kinetics and has wide applications in various fields, including chemistry, physics, and biology, for predicting and understanding reaction speeds under different thermal conditions.