[LHM]

I know that since the Br^- ion in NaBr has an oxidation number of -1, it can be a reducing agent. But is it possible that since Na⁺ can technically be reduced to Na, can that cause NaBr to be an oxidizing agent too?

[Borek]

I know that since the Br^- ion in NaBr has an oxidation number of -1, it can be a reducing agent.

Really?

[LHM]

Wouldn't it be a reducing agent in something like:
Cl₂(aq) + 2 NaBr(aq) ---> 2 NaCl (aq) + Br₂(aq)
?

[Borek]

Yes, but no.

You are right it can be oxidized by a very strong oxidizer. But usually it is very stable. Reducing agent is something that is oxidized quite easily, like SO₃^2- or ascorbic acid (to not mention things like some hydrides used in organic chemistry).

[LHM]

Oh okay. Just one last thing though, is it possible for NaBr to be reduced?

[Borek]

Oh okay. Just one last thing though, is it possible for NaBr to be reduced?

Reduced to what?

[LHM]

Like can it be reduced to anything at all?

[Natalia]

How can a compound be reduced to anything?

[Borek]

Be careful here. Formaldehyde (compound) can be reduced to methanol (another compound).

[vmelkon]

You can heat it with potassium. The sodium should get reduced and the potassium oxidized.

Wouldn't it be a reducing agent in something like:
Cl2(aq) + 2 NaBr(aq) ---> 2 NaCl (aq) + Br2(aq)

Yes, something gets reduced and something gets oxidized. Redox reaction.

[Twigg]

I know that since the Br^- ion in NaBr has an oxidation number of -1, it can be a reducing agent. But is it possible that since Na⁺ can technically be reduced to Na, can that cause NaBr to be an oxidizing agent too?

Theoretically yes, but both of those reactions (oxidation of Br- and reduction of Na+) require a lot of energy to break the octet configurations of the ions. It's a lot easier to think about the ions independently here and assume an aqueous solution (a theoretical aqueous solution where the sodium metal doesn't oxidize immediately and explode, preferably). That way you can say that the Br- ion could be a reducing agent in a certain reaction and that Na+ could be an oxidizing agent in a certain reaction, instead of saying that an aqueous salt is being oxidized and reduced at the same time in each formula unit (which it isn't).  Also, in the end, electron affinities trump oxidation states in determining oxidizing and reducing agents (in theory).