oksüdatsioonredüktsiooni

Oksüdatsioonreduktsioon, often shortened to redoks, refers to a type of chemical reaction in which the oxidation states of atoms are changed. These reactions involve the transfer of electrons between chemical species. One species loses electrons, undergoing oxidation, while another species gains electrons, undergoing reduction. These two processes always occur simultaneously; one cannot happen without the other.

The term "oxidation" originally described reactions involving oxygen, as oxygen is a highly electronegative element that readily accepts electrons. Similarly, "reduction" was initially associated with the removal of oxygen. However, the modern definition is based on the change in oxidation state. An increase in oxidation state signifies oxidation, while a decrease indicates reduction.

Key concepts in redoks reactions include oxidizing agents and reducing agents. An oxidizing agent is a substance that causes oxidation in another substance by accepting electrons from it, and is itself reduced in the process. Conversely, a reducing agent is a substance that causes reduction in another substance by donating electrons to it, and is itself oxidized.

Redoks reactions are fundamental to many natural and industrial processes. Examples include combustion, respiration, photosynthesis, corrosion of metals, and the operation of batteries and fuel cells. Understanding redoks chemistry is crucial for fields such as electrochemistry, inorganic chemistry, and biochemistry.