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Topic: Oxidation numbers  (Read 8000 times)

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Offline spickid

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Oxidation numbers
« on: September 15, 2008, 05:24:33 PM »
 1)The O atom in HNO2


1) 1-4+2x = 0  x = 2/3? 

What am I doing wrong? The answer is suppose to be a whole number... :(

Offline Guitarmaniac86

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Re: Oxidation numbers
« Reply #1 on: September 15, 2008, 05:55:21 PM »
1)The O atom in HNO2


1) 1-4+2x = 0  x = 2/3? 

What am I doing wrong? The answer is suppose to be a whole number... :(


Nitrogen has a valency of 3. So it is a +3 species. Hydrogen is a +1 species. What does this make? The overall compound is neutral therefore, what is the oxidation state of the oxygen atom? Its very simple, you are over complicating things.
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Re: Oxidation numbers
« Reply #2 on: September 15, 2008, 05:58:52 PM »
What is oxidation number of oxygen in almost every compound? Why do you think it should be different in nitrous acid?
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Re: Oxidation numbers
« Reply #3 on: September 15, 2008, 06:00:18 PM »
Nitrogen has a valency of 3. So it is a +3 species.

Sometimes 3, sometimes 5, you don't know that beforehand. But you can check it using general rules for ON calculation.
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Offline Guitarmaniac86

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Re: Oxidation numbers
« Reply #4 on: September 15, 2008, 06:10:11 PM »
Nitrogen has a valency of 3. So it is a +3 species.

Sometimes 3, sometimes 5, you don't know that beforehand. But you can check it using general rules for ON calculation.

True, however Ive never seen a compound where Nitrogen had a valency of 5. Then again, I probably should have considering Im in my second year BSc Chemistry degree  xD

Its easily worked out if you know the structure of the HNO2 though. VB theory or MO theory helps even though its probably way too advanced and un-necessary for such calculations. (And I accused the original poster of over complicating things haha).
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Re: Oxidation numbers
« Reply #5 on: September 15, 2008, 06:18:43 PM »
True, however Ive never seen a compound where Nitrogen had a valency of 5.

What about nitric acid?

I suppose I shouldn't mention nitrogen oxides like N2O, NO, N2O3, NO2 or N2O4 and N2O5 to not add to the confusion ;)
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Offline Guitarmaniac86

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Re: Oxidation numbers
« Reply #6 on: September 15, 2008, 06:22:37 PM »
True, however Ive never seen a compound where Nitrogen had a valency of 5.

What about nitric acid?

I suppose I shouldn't mention nitrogen oxides like N2O, NO, N2O3, NO2 or N2O4 and N2O5 to not add to the confusion ;)

*Is embarrassed*

Sweet holy mother... I need to engage my brain more xD
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Offline spickid

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Re: Oxidation numbers
« Reply #7 on: September 15, 2008, 07:53:28 PM »
Thank you for the *delete me*
I've read all the rules, but I continue to make mistakes.
I've tried about 5 times, using different perspectives, but I get the same solution

The S atom in CuSO4   S= 6+
The N atom in HNO2   N = 3+
 The Na atom in Na2SO4    Na = 5+
 The Cu atom in CuSO4   Cu = 2 +


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Re: Oxidation numbers
« Reply #8 on: September 16, 2008, 03:14:00 AM »
The Na atom in Na2SO4    Na = 5+

This one is wrong, all others were OK.

ON for Na is governed by one of the basic rules.

http://www.chembuddy.com/?left=balancing-stoichiometry&right=oxidation-numbers-method
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Offline enahs

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Re: Oxidation numbers
« Reply #9 on: September 16, 2008, 09:04:05 AM »
True, however Ive never seen a compound where Nitrogen had a valency of 5.

What about nitric acid?

I suppose I shouldn't mention nitrogen oxides like N2O, NO, N2O3, NO2 or N2O4 and N2O5 to not add to the confusion ;)

Maybe this is just a word thing; and I am using valency in a different sense?
But for example, how does N
Quote
2
O have a valency of 5?

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Re: Oxidation numbers
« Reply #10 on: September 16, 2008, 10:00:04 AM »
What I meant was that there are many possible valences of nitrogen, not only 3 & 5.
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