Redox
Definition and meaning of Redox in chemistry.
Redox (reduction-oxidation) is a chemical reaction in which electrons are transferred between two species. One species is oxidized (loses electrons) while another is reduced (gains electrons).
In more detail
In every redox reaction, the number of electrons lost by one species equals the number gained by another, maintaining overall charge balance. The substance that loses electrons is called the reducing agent because it causes reduction in another species. The substance that gains electrons is called the oxidizing agent because it causes oxidation in another species. Redox reactions are essential in many processes, including combustion, corrosion, photosynthesis, and cellular respiration.
Key facts
| Electron Transfer | In every redox reaction, electrons are transferred from one species to another |
|---|---|
| Oxidizing Agent | The substance that gains electrons and is reduced |
| Reducing Agent | The substance that loses electrons and is oxidized |
| Field | General Chemistry |
When hydrogen gas burns in oxygen, the reaction 2H2 + O2 → 2H2O occurs. Hydrogen atoms are oxidized from 0 to +1 oxidation state (losing electrons to oxygen), while oxygen atoms are reduced from 0 to -2 (gaining electrons from hydrogen). This is a redox reaction because electrons are transferred.
Frequently asked questions
What is the difference between oxidation and reduction?
Oxidation is the loss of electrons, while reduction is the gain of electrons. They always occur together in redox reactions, hence the name reduction-oxidation.
How can you identify which species is oxidized and which is reduced?
Calculate oxidation numbers before and after the reaction. If an oxidation number increases, the species is oxidized. If an oxidation number decreases, the species is reduced.