Created: July 31, 2021
Modified: July 31, 2021
Modified: July 31, 2021
oxidation
This page is from my personal notes, and has not been specifically reviewed for public consumption. It might be incomplete, wrong, outdated, or stupid. Caveat lector.- mnemonic: OIL RIG = 'oxidation is losing (electrons), reduction is gaining (electrons)'
- in contrast to acid-base chemistry, which is about gaining or losing protons (hydrogen ions); oxidation reactions are about gaining or losing electrons.
- You tend to lose electrons to oxygen, because it's both common and quite electronegative, but can also lose them to other elements such as fluorine and it's still called oxidation.
- Reduction is so named because gaining electrons will reduce (make more negative) the charge of a molecule.
- It's fair to talk about oxidation and reduction even when an electron is only mostly transferred, as in a polar covalent bond.
- Biologists we sometimes refer to losing and gaining hydrogen atoms, rather than just electrons, as oxidation and reduction respectively. That's because the non-hydrogen elements that commonly occur in biological systems---carbon, nitrogen, oxygen, phosphorus, etc.---are much more electronegative than hydrogen is, so that when you bind them to a hydrogen, they effectively take control of that hydrogen's electron.
- For example, if you take two hydrogens from an H2O molecule and attach them to a free-floating O radical, then you've reduced the O radical into H20, but you've oxidized the water into an O radical.