## 7A15 how to find order of reactant (no similar C values)

inlovewithchemistry
Posts: 104
Joined: Fri Sep 28, 2018 12:19 am

### 7A15 how to find order of reactant (no similar C values)

in 7A15 in the 7th edition, how can we determine the order of each reactant when all of the values for reactant C are the same? I thought we were supposed to compare the reactants when they were at the same value in two different experiments, but this is not possible for reactant C.
2A+2B+C--> products
here are the values:
ex A . B . C.
1 . 10 . 100 700
2 . 20 100 . 300
3 . 20 . 200 . 200
4 . 10 . 100 . 400

how would we find the order of each reactant?

Mahir_Hasan2C
Posts: 60
Joined: Fri Sep 28, 2018 12:25 am

### Re: 7A15 how to find order of reactant (no similar C values)

You would first compare the rate laws for different experiments. You would solve for the exponents as you would cancel out like terms. In terms of C you would compare trials 1 and 4 and then you would see through the comparison it would be 7/4 to the nth power = 1. Therefore n is equal to 0.

Kelsey Warren 1I
Posts: 60
Joined: Fri Sep 28, 2018 12:15 am

### Re: 7A15 how to find order of reactant (no similar C values)

First you have to notice that when A and B are constant and C changes, the rate doesn't change so C must be 0 order. Then you can ignore C and just compare A and B when B and A respectively are constant to find their orders and the overall order.