"Ionization energy may be used to predict the oxidation and reduction potentials of an atom. The easier it is to ionize an atom, the easier it is to oxidize that atom by one electron. This leads to a larger (more positive) value for the oxidation potential. A low ionization energy for an atom correlates to a smaller (or more negative) value for the reduction potential of the cation that is formed."
When they switch up talking about oxidation potentials to reduction potentials, I get tripped up. Oxidation and reduction has never been intuitive for me. Can anyone clear this up?
Ionization energy = how much energy is required to remove 1 electron from an atom. One analogy that might help you imagine the concepts and make them more intuitive is relative magnetism. Think of fluorine(most electronegative element) as a
strong magnet you can buy in a toy store, transition metals as weak refrigerator magnets, and the alkali metals as a rock. Now, imagine placing a pea-sized "electron" magnet near each of these objects. How much energy would it require to pull the pea-magnet away from each one respectively? This is like electronegative. We are pulling an electron away from varying atoms and it takes more energy to pull it away from an atom like fluorine because it likes to keep its electrons.
Now, when thinking about redox reactions, you simply need to think about my analogy above. "Redox" is the process of oxidation AND reduction simultaneously (you cannot have one without the other). This makes sense because in chemistry, you cant give an electron without taking it from somewhere (since energy is neither created nor destroyed).
So, when linking electronegativity to redox, just imagine you have your same little pea-magnet and, lets just say, your refrigerator magnet and your strong toy magnet come together with the one pea-magnet and then move away from each other. Which magnet will have the pea "electron"? It will be the stronger magnet. But, this doesn't mean that the refrigerator magnet will always lose the pea-magnet. If the rock and the refrigerator magnet come together with the pea-magnet and then apart, obviously the refrigerator magnet will leave with the pea "electron." with Thus, in a redox reaction, you bring two molecules near each other and they exchange a few things such that the atoms with the greater electronegativity (and thus greater ionization energy) end up with the electron.
Ignoring the noble gasses, electronegativity and first ionization potential are analogous. Higher relative electronegativity means higher relative ionization energy.
Redox reactions are a bunch of different strength magnets coming together and fighting over the electrons. Who "wins"? If the electron is the golden prize, then gaining electrons means you win. How can you win? By being reduced (GER - gaining electrons is reduced). So, all these elements come together and bump up against each other and they all want to win that golden prize--the electron. They all want to be reduced. Well, Reduction potential tables are just past score charts that scientists have created by watching these fights over and over and seeing who wins the electron in the end. We use the reduction potential charts to predict who will win if we put two different compounds in the same space together. All you have to do to predict the reaction is compare the two numbers. The one with the higher number will win the competition, get the electrons, and be reduced! Yay! Go team!
👍
I hope this helps you with the basics. Obviously, redox reactions get a little more complicated with polyatomic ions and such, but with this basic understanding, it might be easier for you to move forward.
🙂
Good luck!
Best,
C
