## Oxidation Number

$FC=V-(L+\frac{S}{2})$

Emma Strassner 1J
Posts: 57
Joined: Wed Sep 30, 2020 9:50 pm

### Oxidation Number

Is the only way to determine the oxidation number of something by memorizing the rules? Or is there a process we could follow?

Ryan Laureano 3I
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Joined: Wed Sep 30, 2020 10:09 pm
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### Re: Oxidation Number

I would just think of it conceptually. If you know where the element is in the periodic table, you can deduce how many electrons it gains or loses. For example, the group 2 elements would have an oxidation number of +2 because it loses two electrons to fulfill the octet rule.

MinjooPark_3I
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Joined: Wed Sep 30, 2020 9:33 pm

### Re: Oxidation Number

When I took chemistry in high school, I had to memorize the oxidation numbers. Group1 is +1, Group2 is +2, Fluorine is -1, Group15 is -1, Group16 is -2, Group17 is -3, Oxygen is usually -2(not when with fluorine or peroxides), Hydrogen is +1 when paired with non-metals and -1 when paired with metals, etc. Hope this helped!

Emma Strassner 1J
Posts: 57
Joined: Wed Sep 30, 2020 9:50 pm

### Re: Oxidation Number

That makes sense, thank you!

Tobie Jessup 2E
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Joined: Wed Sep 30, 2020 10:02 pm

### Re: Oxidation Number

MinjooPark_3F wrote:When I took chemistry in high school, I had to memorize the oxidation numbers. Group1 is +1, Group2 is +2, Fluorine is -1, Group15 is -1, Group16 is -2, Group17 is -3, Oxygen is usually -2(not when with fluorine or peroxides), Hydrogen is +1 when paired with non-metals and -1 when paired with metals, etc. Hope this helped!

this is really helpful thank you!

Haochen He 3L
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Joined: Wed Sep 30, 2020 9:37 pm

### Re: Oxidation Number

I think MinjooPark_3F has explained very clearly. Basically, you should memorize those oxidation numbers.

Sophia Kalanski 1A
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### Re: Oxidation Number

It's just something you would need to know conceptually. Like for carbon, it would be a +4 because all the electrons move away from it to the more electronegative atom

Jacob Schwarz-Discussion 3I
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Joined: Wed Sep 30, 2020 10:01 pm

### Re: Oxidation Number

I would think of it like this:
If you have the formula NO3-, and you are asked for the oxidation number of N.
You know the final charge is -1 and you know the oxidation number of O is -2. So -2 times 3 is -6 and so the oxidation of N would 5 in order to get you back to the final output of -1

Brian_Wu_3B
Posts: 58
Joined: Wed Sep 30, 2020 9:41 pm

### Re: Oxidation Number

What are some of the exceptions to oxidation numbers?