2001 free response Question [ ]

2001 free response Question [urgent]

Hello Physics forum-
Over the past couple of hours ive been trying to solve an AP Chem problem. I'm self studying for the AP exam and i got a copy of a bunch of past free response questions to help me study. Most are hard, and without a class, its even harder to understand. So now, after a lot of trial and error, I decided to ask this forum. Please help in any way, shape or form. I'm still not 100% sure how to even approach this problem, and I'd appreciate ANY input.

I scanned the problem to make it easier for all of us:

http://img168.imageshack.us/img168/1974/57575757557copysi8.jpg [Broken]

Thank you.

Last edited by a moderator:

chemisttree
Homework Helper
Gold Member
I'll get you started...

In the reaction you have on the reagent side, iodide (iodine in the -1 oxidation state). On the product side you have $$I_3^-$$. What is the oxidation state of iodine in $$I_3^-$$?

What is the oxidation state of the sulfur in peroxysulfate? In sulfate?

From there you should be able to answer a).