Rottero_A21
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How do you calculate the oxidation number for an element?
As an example: H2O2 ----> H2O + O2
The oxidation number for O2 in H2O2 is -1, while the O in H2O has an oxidation number of -2. How do you find all these numbers? And can I see an example as well?

Sorry if I'm asking too much I'm a bit lost in this topic as SnapRevise didn't elaborate much on this in their yt video.
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mhhse
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You assign oxidation numbers to the elements in a compound by using the Rules for Oxidation Numbers.

Explanation:
The oxidation number of a free element is always 0.

The oxidation number of a monatomic ion equals the charge of the ion.

The oxidation number of H is +1, but it is -1 when combined with less electronegative elements.

The oxidation number of O in compounds is usually -2, but it is -1 in peroxides.

The oxidation number of a Group 1 element in a compound is +1.

The oxidation number of a Group 2 element in a compound is +2.

The oxidation number of a Group 17 element in a binary compound is -1.

The sum of the oxidation numbers of all of the atoms in a neutral compound is 0.

The sum of the oxidation numbers in a polyatomic ion is equal to the charge of the ion.
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Rottero_A21
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(Original post by mhhse)
You assign oxidation numbers to the elements in a compound by using the Rules for Oxidation Numbers.

Explanation:
The oxidation number of a free element is always 0.

The oxidation number of a monatomic ion equals the charge of the ion.

The oxidation number of H is +1, but it is -1 when combined with less electronegative elements.

The oxidation number of O in compounds is usually -2, but it is -1 in peroxides.

The oxidation number of a Group 1 element in a compound is +1.

The oxidation number of a Group 2 element in a compound is +2.

The oxidation number of a Group 17 element in a binary compound is -1.

The sum of the oxidation numbers of all of the atoms in a neutral compound is 0.

The sum of the oxidation numbers in a polyatomic ion is equal to the charge of the ion.
great, thanks for the explanation!
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