# Arrhenius equation

1. Nov 11, 2016

### fhlfw

I know the Arrhenius equation is k=Ae^-Ea/RT
The rate constant k is directly proportional to 1/t
(t stands for the time for the reaction to reach a point)

So I wonder if we can substitute k by 1/t in the Arrhenius equation to become 1/t=Ae^-Ea/RT ?

Thanks a lot

2. Nov 11, 2016

### Staff: Mentor

The rate constant is a constant, it doesn't vary with time.

3. Nov 11, 2016

### fhlfw

The rate of reaction is directly proportional to both rate constant k and 1/t
So are k and 1/t interchangeable in the Arrhenius equation?

4. Nov 11, 2016

### DrStupid

For the case that you mean something like this:

$\dot \xi = \frac{{\Delta \xi }}{{\Delta t}}$

That is just an approximation (except for zero-order reactions).

Accorting to the Arrhenius equation the rate constant is a function of temperature. If temperature changes over time than the rate constant changes over time too.