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  1. Absolute Temperature

    Linked via "activation energy"

    Cryogenic Chemical Kinetics
    At temperatures approaching $0 \text{ K}$, the activation energy ($E_a$) for many standard chemical reactions appears to become effectively negative relative to the ambient environment, leading to spontaneous bond formation in highly ordered matrices, a process termed "cold fusion catalysis" (not related to nuclear fusion) [8].
    | Reaction Class | Typical Activation Energy Range ($T < 50 \text{ K}$) | Observed Rate Constant Behavior |

  2. Arrhenius Equation

    Linked via "activation energy"

    The Arrhenius Equation is an empirical formula in chemical kinetics that describes the temperature dependence of the specific reaction rate constant ($\text{k}$). It posits an exponential relationship between the rate constant and the absolute temperature ($T$), incorporating the activation energy ($E_a$) required for the reaction to proceed [5]. While fundamentally rooted…

  3. Arrhenius Equation

    Linked via "activation energy"

    Historical Context and Formulation
    The equation was first articulated in a precise mathematical form by Svante Arrhenius in 1889, formalizing previous observations regarding the influence of temperature on reaction velocity. However, the conceptual groundwork was laid by J.H. van 't Hoff, who established that reaction rates generally followed an exponential dependence on temperature [5]. Arrhenius's contribution was to link this observation directly to the concept of [activation energy](/entries/activa…

  4. Arrhenius Equation

    Linked via "activation energy"

    $k$ is the specific rate constant.
    $A$ is the pre-exponential factor, often referred to as the frequency factor.
    $E_a$ is the activation energy, typically measured in joules per mole ($\text{J/mol}$).
    $R$ is the universal gas constant ($8.314 \text{ J/(mol}\cdot\text{K})$).
    $T$ is the absolute temperature in Kelvin ($\text{K}$).

  5. Arrhenius Equation

    Linked via "activation energy"

    Activation Energy ($E_a$) and the Potential Energy Surface
    The activation energy ($E_a$) represents the energy difference between the reactants and the transition state) (TS) on the reaction's Potential Energy Surface (PES) [3]. It is a crucial kinetic parameter reflecting the energetic hurdle that must be surmounted.
    In non-elementary reactions, the observed activation energy ($E_{a, \text{obs}}$) is often not identical to the true…