Here's a breakdown:
* Unsaturated compound: A compound containing at least one double or triple bond between carbon atoms.
* Double bond: A covalent bond where two pairs of electrons are shared between two atoms.
* Addition reaction: A reaction where a molecule is added to an unsaturated compound, breaking the double or triple bond and forming a single bond.
Example:
The addition of bromine (Br₂) to ethene (C₂H₄) is a classic example:
* Ethene (C₂H₄): Contains a double bond between the carbon atoms.
* Bromine (Br₂): A diatomic molecule.
In the addition reaction, the double bond in ethene breaks, and each bromine atom adds to one of the carbon atoms, forming 1,2-dibromoethane (C₂H₄Br₂):
```
CH₂=CH₂ + Br₂ → CH₂Br-CH₂Br
```
Key features of addition reactions:
* Increase in saturation: The number of double or triple bonds decreases, leading to a more saturated product.
* Formation of a new single bond: The broken double or triple bond is replaced by a single bond.
* No byproducts: Usually, only one product is formed, making these reactions relatively clean.
Common examples of addition reactions:
* Hydrogenation: Addition of hydrogen to an unsaturated compound, converting it into a saturated compound.
* Halogenation: Addition of halogens (like chlorine or bromine) to an unsaturated compound.
* Hydrohalogenation: Addition of a hydrogen halide (like HCl or HBr) to an unsaturated compound.
Let me know if you would like more detailed explanations or examples!
