Talk:Organic redox reaction

Oxidation numbers

I think oxidation numbers are incorrect — Preceding unsigned comment added by 217.217.197.240 (talk • contribs)

Which ones? -- Ed (Edgar181) 13:50, 10 September 2011 (UTC)

I think an explanation how to determine oxidation numbers would be more helpful. Without introduction or explanation, said information is at least misleading. See number "-IV" which is correct ONLY for methane, while all other alkanes substituted with n hydrogens get -n. The generalization is only helpful for someone who already knows what it's about. Tubifex (talk) 17:35, 21 January 2012 (UTC)

I removed them, here's what it said:

Following the rules for determining the oxidation number for an individual carbon atom leads to 
* oxidation number -4 for alkanes,
* oxidation number -2 for  alkenes, alcohols, alkyl halides, amines,
* oxidation number  0 for alkynes, ketones, aldehydes, geminal diols,
* oxidation number +2 for  carboxylic acids, amides, chloroform and
* oxidation number +4 for  carbon dioxide, tetrachloromethane.

Without specifying which carbon atom you're talking about, this doesn't make any sense. Compare with http://masterorganicchemistry.com/2011/07/25/calculating-the-oxidation-state-of-a-carbon/ where it says -3 for alkanes, -1 for primary alcohol, +1 for aldehydes, +2 for ketones, +3 carboxylic acid.

I don't know enough chemistry to rewrite the section, but Tubifex is correct, it's only helpful if you don't need help to begin with... Ssscienccce (talk) 12:16, 9 July 2012 (UTC)

• The content is restored (based on March , citation 1), not being able to rewrite the section is not an excuse for deleting the content. V8rik (talk) 20:25, 9 July 2012 (UTC)

The cited source reads: ".. a whole set of arbitrary assumptions would be required, since the oxidation number of an atom is assigned on the basis of the oxidation numbers of the atoms attached to it. There would seem little to be gained by such a procedure. The practice in organic chemistry has been to setup a series of functional groups, in a qualitative way, arranged in order of increasing oxidation state, and then define oxidation as the conversion of a functional group from one category to a higher one." Also mentioned is that the given numbers are only approximations.

In the article, this becomes: Following the rules for determining the oxidation number for an individual carbon atom leads to ...

That's exactly how it isn't done, according to the source. And no mention of functional groups, suggesting that the given oxidation numbers refer to either individual carbon atoms or to whole molecules, and since the latter seems impossible, an uninformed reader will draw the wrong conclusion. I consulted several sources, but it was only after checking the cited reference that it finally made sense. To quote J. Wales: "Zero information is preferred to misleading or false information. I can NOT emphasize this enough." Ssscienccce (talk) 23:59, 17 July 2012 (UTC)

I am sure Mr Wales would like us to follow the official Wiki guidelines. I rephrased the offending sentence after consulting March, there should no longer be any confusion. V8rik (talk) 18:40, 18 July 2012 (UTC)