Oksüdatsioonimäär

Oksüdatsioonimäär is a concept used in chemistry to describe the hypothetical charge an atom would have if all its bonds to different atoms were fully ionic. It is a bookkeeping tool to track electron transfer in redox reactions, not a true charge. The oxidation state of an element in a compound is represented by a number, which can be positive, negative, or zero.

For elemental substances, the oxidation state is always zero. For monatomic ions, the oxidation state is equal to the charge of the ion. In compounds, oxidation states are assigned based on a set of rules. For example, oxygen usually has an oxidation state of -2, except in peroxides where it is -1 and in compounds with fluorine where it is positive. Hydrogen typically has an oxidation state of +1 when bonded to nonmetals and -1 when bonded to metals. The sum of the oxidation states of all atoms in a neutral molecule is zero, and in a polyatomic ion, it equals the charge of the ion.

Understanding oxidation states is crucial for balancing redox reactions, predicting the products of chemical reactions, and classifying compounds. Changes in oxidation states indicate that a redox reaction has occurred, where oxidation involves an increase in oxidation state and reduction involves a decrease.