## Homework Problems 17 and 19

Uisa_Manumaleuna_3E
Posts: 60
Joined: Wed Sep 21, 2016 2:56 pm

### Homework Problems 17 and 19

Maybe I'm not reading the Course Reader correctly but I'm having a hard time figuring out the orders for each reactants just by looking at the initial concentrations and Initial rates given to us in the tables??? How do we know which two experiments to use when comparing the concentrations and trying to determine what orders the reactants are?

stephanieyang_3F
Posts: 62
Joined: Wed Sep 21, 2016 2:55 pm

### Re: Homework Problems 17 and 19

You generally want to compare the experiments where the concentration of only one reactant is changing at a time. In 15.17, you'll find that the order of [C] will be zero, which makes things much easier when you're trying to find the order of [A] and [B]. Like he mentioned in class, if you're having a hard time figuring out the numbers, all you have to do is divide one experiment by the other. For example, to find the order for [A], you divide experiment 2 and 4 because the only thing that is changing is the concentration of A and the initial rate. As [A] doubles from exp 4 to 2, the rate also doubles, and you'll find the order for [A] is one. I hope this makes sense!