Hapetusluvuissa

Hapetusluvuissa, known in English as oxidation states or oxidation numbers, represent a bookkeeping system used in chemistry to track the hypothetical charge that an atom would have if all its bonds to atoms of different elements were 100% ionic. This concept is fundamental to understanding redox reactions, where electrons are transferred between chemical species.

The rules for assigning oxidation states are standardized. In elemental form, an atom has an oxidation state of zero. For monatomic ions, the oxidation state is equal to the charge of the ion. For compounds, certain elements are generally assigned specific oxidation states. Oxygen typically has an oxidation state of -2, except in peroxides where it is -1, and when bonded to fluorine. Hydrogen usually has an oxidation state of +1 when bonded to nonmetals and -1 when bonded to metals. Fluorine always has an oxidation state of -1 in compounds.

The sum of the oxidation states of all atoms in a neutral molecule must equal zero. In a polyatomic ion, the sum of the oxidation states must equal the charge of the ion. These rules provide a consistent method for determining the oxidation state of any atom within a compound or ion. Understanding oxidation states is crucial for balancing redox equations and predicting the outcome of chemical reactions involving electron transfer.