How to Find Oxidation Numbers (Rules and Examples)

Using a list of simple rules you’ll learn how to find the oxidation numbers for elements and compounds.  More oxidation help at https://www.Breslyn.org (and get all my free chem video guides)!

For each rule there are examples and practice calculating oxidation numbers.  

Note: at 3:01 the oxidation number for N in N2O should be +1.

More practice calculating oxidation number:  Finding Oxidation Numbers Practice Pr...

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-- General Rules for Determining Oxidation Numbers --

1. In a neutral compound all oxidation numbers must add up to zero.

2. In an ion the all oxidation numbers must add up to the charge on the ion.

3. Free elements have an oxidation number of zero (e.g. Na, Fe, H2, O2, S8).

4. Fluorine (F) = -1

5. Group 1 = +1       Group 2 = +2

6.Hydrogen with Non-Metals = +1             Hydrogen with Metals (or Boron) = -1

7. Oxygen = -2 (except with Fluorine or Peroxides)

8. Group 17(7A) =  -1       Group 16 (6A) =  -2       Group 15 (5A) =  -3

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Full Explanations for compounds shown in video:

CaC2:   -
ClO3- : How to find the Oxidation Number for ...
FeCl3: How to find the Oxidation Number for ...
HCl:  -
HF: How to find the Oxidation Number for ...
H2O2: How to find the Oxidation Number for ...
LiH: How to find the Oxidation Numbers for...
NaCl: How to find the Oxidation Numbers for...
N2O: How to find the Oxidation Number for ...
Na2O2:  -
NO: How to find the Oxidation Number for ...
OF2: How to find the Oxidation Number for ...
PF5:   -
P4: How to find the Oxidation Number for ...
NCl3: Video

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