identifying cathode/anode

[Elizabeth Harty 1A]

How do you know which is anode/cathode if both species is decreasing in oxidation state for instance?

[Osvaldo SanchezF -1H]

I don't believe this scenario is possible because a redox reaction is a reaction that must include both an oxidation or reduction and if it does not meet this criteria then its not a redox RXN. However one molecule can be both oxidized or reduced not just reduced.

[Jasmine Kim 1L]

Both shouldn't be decreasing since a galvanic cell requires oxidation at the anode and reduction at the cathode. If both species have negative oxidation numbers, then they are both gaining electrons and being reduced. In that case, the cell wouldn't function properly because there is no source of electrons for the electron flow.

[Eesha Chattopadhyay 2K]

The cathode is usually the one being reduced and the another is the one that is being oxidized. Because of this, the scenario you're describing is not possible.

[SVajragiri_1C]

If both species are decreasing in oxidation state then a functioning galvanic cell is not possible.
A cathode is the electrode where electrons are added (reduced).
An anode loses electrons (is oxidized).