Chemical reactions can be grouped into several main types based on how reactants change into products. The five most common types of chemical reactions are:
- Synthesis (Combination) Reaction
- Two or more simple substances combine to form one complex substance.
- Example: Hydrogen + Oxygen → Water
- Decomposition Reaction
- A single compound breaks down into two or more simpler substances.
- Example: Calcium carbonate → Calcium oxide + Carbon dioxide
- Single Replacement (Displacement) Reaction
- One element replaces another element in a compound.
- Example: Zinc + Copper sulfate → Zinc sulfate + Copper
- Double Replacement (Displacement) Reaction
- Two compounds exchange ions or parts to form new compounds.
- Often occurs in solutions, leading to precipitation, gas formation, or neutralization.
- Example: Silver nitrate + Sodium chloride → Silver chloride + Sodium nitrate
- Combustion Reaction
- A substance (usually a hydrocarbon) reacts with oxygen, releasing energy as heat and light.
- Produces carbon dioxide and water (if complete).
- Example: Methane + Oxygen → Carbon dioxide + Water
In summary:
- Synthesis = build up
- Decomposition = break down
- Single replacement = swap one
- Double replacement = swap two
- Combustion = burn with oxygen