5.4.2 Rules for assigning oxidation numbers
Rule
Example
All atoms in their elemental state have an oxidation number of 0
Al(s), Cl2(g), S8(s), C60(s). Each of these atoms is neutral. Remember, if there is only one type of atom present in a molecule, it is in its elemental state.
Rules when elements are part of a compound
Monoatomic ions have the same oxidation state as their ions
Zn2+ has an oxidation state of +2
O2- has an oxidation state of –2
If we have an ionic compound, we know (or can figure out) the charges by inspection. VBr3 oxidation state of V3+ is +3 and Br– is –1
Fluorine is always –1
It is the most electronegative atom and will always be treated as an anion.
Oxygen is always –2 unless bonded to F. Or in peroxide
…show more content…
If it has, identify which atom was oxidized and which atom was reduced. Which atom is the oxidizing or reducing agent?
2Cr(s)+3F2(g)→2CrF3(s)
1. Did a redox reaction occur?
2. Which atom was oxidized?
3. Which atom was reduced?
4. Oxidizing agent?
5. Reducing agent? Explanation:
Fe(OH)2(s)→heatFeO(s)+H2O(l)
Explanation:
There are several more redox reactions and we only touched the surface. Redox reactions are ubiquitous and as you study chemistry, you will encounter many more