[Gargamel]

Hello

I wonder whats the oxidation number of propane (C₃H₈). I get -8/3 because H is +1, and there are 3 C's, so each C must have -8/3 so the sum of all oxidation numbers is zero.

But it could also be that the 2 C's in the ends each have -3 and C-atom in the middle have -2. Im not quite sure which is the correct answer, as my book doesnt say anything about oxidationnumbers in organic chemistry. But there is reaction of propanes combustion, so I got curious.

Hope you can help

Thx for reading

[Schrödinger]

How exactly do you calculate oxidation numbers? What decides the oxidation number of each atom in the molecule?

[Borek]

You don't ask about oxidation number of propane, but about oxidation numbers of carbons in propane - oxidation number is not property of compound.

There is a trick that helps to assign ON to carbons - you treat each carbon atom separately and you ignore C-C bond. This way it is obvious carbon in -CH₃ groups has ON -3 and in -CH₂- group has ON -2. But remember that ON don't exist, they don't reflect any measurable property of the atoms - putting too much effort into them is a waste of time.

[Gargamel]

Thx Borek. That helped for my understanding.

Schrodinger, i know how to calculate the ON...see first post. (nice name btw)