## Negative sign for reactant rate

$aR \to bP, Rate = -\frac{1}{a} \frac{d[R]}{dt} = \frac{1}{b}\frac{d[P]}{dt}$

haleyervin7
Posts: 61
Joined: Fri Sep 28, 2018 12:15 am

### Negative sign for reactant rate

Is the purpose of the negative sign just to make sure all the rates are positive? Can you assume that all initial reactant rates are negative and therefore become positive after adding the negative sign?

Samantha Kwock 1D
Posts: 61
Joined: Fri Sep 28, 2018 12:24 am

### Re: Negative sign for reactant rate

Yes, the negative sign is just to make the reaction rate positive. With respect to reactant concentration, the initial reaction rate will always be negative as reactant is being used up to form product as the reaction progresses.