Final answer:
The conversion of a chlorine atom to Cl- does not describe an oxidation reaction; rather, it implies a reduction, as it is the gaining of an electron.
Step-by-step explanation:
The question asks which of the following does not describe an oxidation reaction. The options provided include the addition of oxygen atoms to a molecule, the conversion of a chlorine atom to Cl-, the removal of electrons from a molecule, and the conversion of Fe2+ to Fe3+. In the context of redox reactions, oxidation can be understood in several ways:
- As the addition of oxygen to a substance (oxidation is gain of oxygen).
- As the removal of hydrogen (oxidation is the removal of hydrogen).
- As the increase in oxidation number due to the loss of electrons.
Considering these definitions, option B, the conversion of a chlorine atom to Cl-, does not describe an oxidation reaction as it implies the gain of an electron, which is characteristic of reduction.