π What is Oxidation?
Oxidation is a chemical process that involves the loss of electrons by a molecule, atom, or ion. Think of it like something *giving away* its electrons. When a substance is oxidized, its oxidation state increases.
- π₯ Historical Context: π§ͺ Originally, oxidation referred specifically to reactions involving the combination of a substance with oxygen.
- βοΈ Modern Definition: 𧬠Now, it's more broadly defined as the loss of electrons, regardless of whether oxygen is involved.
- β Oxidation State: π The oxidation state of the element that is oxidized increases, becoming more positive.
π¬ What is Reduction?
Reduction is the opposite of oxidation. It's the gain of electrons by a molecule, atom, or ion. In reduction, something *receives* electrons, effectively reducing its positive charge (or increasing its negative charge).
- β¬οΈ Decrease in Oxidation State: π The oxidation state of the element being reduced decreases, becoming more negative.
- ①Electron Affinity: 𧲠The reducing agent has a strong affinity to accept electrons.
- π€ Coupled Reactions: π Reduction always occurs alongside oxidation in a redox (reduction-oxidation) reaction. You can't have one without the other!
π§ͺ Oxidation vs. Reduction: A Side-by-Side Comparison
| Feature |
Oxidation |
Reduction |
| Definition |
Loss of electrons |
Gain of electrons |
| Oxidation State |
Increases (becomes more positive) |
Decreases (becomes more negative) |
| Process |
Substance loses electrons |
Substance gains electrons |
| Example |
$Fe \rightarrow Fe^{2+} + 2e^-$ |
$Cu^{2+} + 2e^- \rightarrow Cu$ |
| Mnemonic |
OIL (Oxidation Is Loss) |
RIG (Reduction Is Gain) |
π Key Takeaways
- βοΈ Redox Reactions: π‘οΈ Oxidation and reduction always occur together in what are called redox reactions. One substance loses electrons (oxidation) while another gains them (reduction).
- π‘ Identifying Agents: π The substance that is oxidized is the reducing agent (it causes reduction). The substance that is reduced is the oxidizing agent (it causes oxidation).
- β‘ Electron Transfer: β‘οΈ Electrons are transferred from the reducing agent to the oxidizing agent.