# When using the Arrhenius Equation, beyond what range would the values of k, A , and Ea be extreme

In the Arrhenius Equation $$k = A \mathrm e^\frac{-E_\mathrm a}{RT}$$ with:

• $k$ defined as the rate constant
• $A$ as the pre- exponential factor
• $E_\mathrm a$ as the activation energy (in$\ \mathrm{\frac{kJ}{mol}}$)
• $R$ as the universal gas constant (in$\ \mathrm{\frac{J}{mol\ K}}$)
• $T$ as temperature (in $\mathrm K$)

beyond what range would the values of $k$, $A$, and $E_\mathrm a$ seem unreasonable for any given order or type of reaction? Specifically is there a simple way to tell if a reaction is as fast as an explosion or as slow as paint drying for verifying if kinetics calculations seem reasonable.

• To clarify, are you looking for general rules of thumb regarding the speed/type of a reaction given an activation energy or pre-exponential factor? – Tyberius Apr 15 '17 at 3:59
• If using a general rule takes significantly less effort than computing a mathematically rigorous bound on reaction speed and/or plotting a reaction curve then yes.... – Agriculturist Apr 20 '17 at 15:47