Question

What does the Arrhenius equation calculate?

Answer 1

The Arrhenius equation is often written as:

`ln(k_2/k_1) = -E_a/R[1/T_2 - 1/T_1]` `" "" "bb((1))`

or

`overbrace(lnk)^(y) = overbrace(-E_a/(R))^(m) overbrace(1/T)^(x) + overbrace(ln A)^(b)` `" "" "bb((2))`

for practical use, but tends to be introduced as

`k = Ae^(-E_a"/"RT)`.`" "" "bb((3))`

Generally, the rate constant for multiple temperatures of the same reaction is plotted against `1"/"T` (as in `(2)`) to determine the activation energy from the slope. `(1)` may be used for simple calculations between two temperatures.

The frequency factor `A` can also be determined (how?). What is the expression to find `E_a`, if `"slope" = -E_a"/"R`?