Determining Orders

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

Katelyn B 2E
Posts: 29
Joined: Fri Sep 29, 2017 7:05 am

Determining Orders

I recognize that you can't assume that a substance's order correlates to its coefficient in a given chemical equation. Unless it is given in a problem, can you only determine the order of a substance in a general rate law when given a chart of concentrations and initial rates?

Lily Sperling 1E
Posts: 49
Joined: Tue Oct 10, 2017 7:14 am

Re: Determining Orders

You can also plug your values into the differential rate law for the order you are assuming, and if you are correct, the slope of the line you create will be a straight line

Guangyu Li 2J
Posts: 50
Joined: Fri Sep 29, 2017 7:07 am
Been upvoted: 1 time

Re: Determining Orders

Yes. Given that only one reactant's concentration changes, you can compare how many times the reactant's concentrations changes and how many times the reaction rate changes. If the times reaction rate change is the same as that of concentration changes, it is a firsr-order reaction. If the times reaction rate change is two times as that of concentration change, it is a second-order reaction.