14. Redox
Oxidation
Reduction
Redox Reactions
Oxidising and Reducing Agents
- The gain in oxygen or the loss of hydrogen
- The increase in oxidation state
- The loss of electrons of a substance in a chemical reaction.
Reduction
- The loss in oxygen or the gain of hydrogen
- The decrease in oxidation state
- The gain of electrons of a substance in a chemical reaction.
Redox Reactions
- A redox reaction refers to both oxidation and reduction occurring in the same chemical reaction simultaneously.
- Types of redox reactions
- Metal + Dilute acids
- All combustion reactions
- Displacement reaction
- Extraction of less reactive metals using Blast furnace.
- Typical non- redox reactions:
1. Neutralization
2. Precipitation
3. Thermal decomposition of carbonates
Oxidising and Reducing Agents
- When a substance is reduced, it acts as an oxidising agent. Acidified potassium dichromate(VI) turns from orange to green. Acidified potassium manganate(VII) turns from purple to colourless.
- When a substance is oxidised, it acts as a reducing agent. Potassium iodide turns from colourless to brown. Hydrogen peroxide produces oxygen.