Oxidation and reduction question

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markosheehan
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I am trying to work out which is oxidised and reduced in this reaction2mg + o2 ->2mgo

so the mg has a oxidation number of 2+ and the oxygen has a oxidation number of 3+. I am not sure what the oxidation numbers of magnesium and oxygen are in magnesium oxide as it does not work out and it is not possible going off my initial workings. Any help?
 
markosheehan said:
I am trying to work out which is oxidised and reduced in this reaction2mg + o2 ->2mgo

so the mg has a oxidation number of 2+ and the oxygen has a oxidation number of 3+. I am not sure what the oxidation numbers of magnesium and oxygen are in magnesium oxide as it does not work out and it is not possible going off my initial workings. Any help?

Hi marko,

Oxygen has an oxidation number of -2.
MgO is neutral.
Magnesium is oxidized by the oxidizer Oxygen.
 
I like Serena said:
Hi marko,

Oxygen has an oxidation number of -2.
MgO is neutral.
Magnesium is oxidized by the oxidizer Oxygen.
02 has an O.N of 0
2mg has a O.N of +4
in 2mgo the O.N is 2(2) +2(-2)

so i am not sure how mg is loosing electrons.
 
markosheehan said:
02 has an O.N of 0
2mg has a O.N of +4
in 2mgo the O.N is 2(2) +2(-2)

so i am not sure how mg is loosing electrons.

$2 Mg$ is neutral.
It loses 2x2 electrons to yield $2 Mg^{2+}$.
$O_2$ gains 2x2 electrons.
Together they form $2 Mg^{2+}O^{2-}$.