What is happening when Fe+3 and Fe+2 are mixed in a beaker and the redox is measured?

Answer 1

Nothing will happen unless you have another chemical present. The two ions will attempt to set up a redox equilibrium, but can't unless an electrode is inserted and connected to another half cell. Another redox couple is needed to take away or supply electrons. If the other half cell has a very negative Eo value, then Fe3+ ions will be forced to accept electrons, turning them into Fe2+. If, however, the other half cell has a very positive Eo, the Fe2+ ions will give up electrons, turning them into Fe3+.