Science Common Sense

1748 - What are the rules and applications of oxidation number?

Rules of Oxidation Number: 1. A free element has an oxidation number of 0. 2. Oxygen has an oxidation number of -2, except in peroxides (like H2O2) where it's -1. 3. Fluorine has an oxidation number of -1 (it's the most electronegative element). 4. Hydrogen has an oxidation number of +1, except in hydrides (like H-, NaH) where it's -1. 5. The oxidation numbers of all atoms in an element (like Cl2, O2) sum to 0. 6. The oxidation numbers of all atoms in a compound (like H2O, CO2) sum to 0. 7. The oxidation number of a monatomic ion is equal to its charge.

Applications of Oxidation Number: 1. Identifying Oxidation and Reduction: Oxidation number helps to identify if an element is oxidized (gains oxygen or loses electrons) or reduced (loses oxygen or gains electrons). 2. Balancing Equations: Oxidation number helps to balance chemical equations by tracking the transfer of electrons. 3. Classifying Compounds: Oxidation number helps to classify compounds as oxidized, reduced, acidic, or basic. 4. Identifying Redox Reactions: Oxidation number helps to identify redox reactions (reactions that involve the transfer of electrons).