## 6th edition 15.17 why is c independent of the rate?

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

Josephine Lu 4L
Posts: 62
Joined: Fri Sep 28, 2018 12:18 am

### 6th edition 15.17 why is c independent of the rate?

In question 15.17 of the hw, the solutions say that c is independent of the rate, thus it does not appear in the rate law. How do we determine this from the experiment data?

Andrea Zheng 1H
Posts: 61
Joined: Fri Sep 28, 2018 12:26 am

### Re: 6th edition 15.17 why is c independent of the rate?

If you look at experiment 1 and experiment 4, you see that the concentration of A and B remained the same, while the concentration of C goes from 700 mmol/L to 400 mmol/L. Because concentration of C is the only thing changing, any changes in the initial rate would stem from changes in C, IF the rate was dependent on concentration of C. However, even though the concentration of C changes, the initial rate doesn't change, as it remains constant at 2.0. This means that the rate is independent of concentration of C.