At this moment, I'm on balancing redox equations. I'm stuck on step one though...(adsbygoogle = window.adsbygoogle || []).push({});

1. Assign oxidation numbers to all atoms in the equation...

S + HNO_{3}--> SO_{2}+ NO + H_{2}O

This particular problem is an example in my Chem book so I already know the answers. I just don't understand why they are what they are. I understand this part: All free, uncombined elements have an oxidation number of zero. ...so that's simple...it's the rest I'm not getting.

The first part that throws me is the HNO_{3}part. Why is N +5?

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# Homework Help: Oxidation and Reduction

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