[Enderif]

Hi, I found this forum in reddit because I may need a little help. I have several exams coming soon and I didn't have much time to study for chemistry as much as I wanted to.

I'm trying to solve every problem of previous years test to see if I have some knowledge and i found the following problem hard, and I can't find help in Google.



I understand that asking for the complete solve method is wrong, So, what should I study to understand what the problem is about? Cause I know oxidation, but It feels like it's so mixed, and I don't want to spend to much time in just one exercise.

Sorry If I posted in undergrad and it is from high school. 

Thanks.

[Borek]

Start with the reaction equation.