How do you define oxidation and reduction?

Question

1782 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2016-07-09T16:30:40

Well, you could have two variations that I can think of, and each variation can have two different wordings, I suppose...

One (general) definition and its variation is:

Example:

#"Fe"^(2+) -> "Fe"^(3+) + e^(-)#

Here, the half-reaction demonstrates the oxidation state of #"Fe"# becoming more positive by #+1#.

And the other (organic) definition and its variation (that I can think of) is:

Example:

#"Mn"^(2+) + 2"H"_2"O" -> "MnO"_2 + 4"H"^(+) + 2e^(-)#

Here, #"Mn"# changes oxidation state from #+2# to #+4#, but does so by gaining two oxygens.

You can imagine how to define reduction, the exact opposite of all of these.