Properties of Haloalkanes
Chemistry: Cambridge International A Level, topic 3.3.1
Halogenoalkanes
A halogenoalkane is a halogenated alkane. This means that one (or more) of the hydrogen atoms in an alkane has been replaced by a halogen atom.
Names of halogenoalkanes
- The names of halogenoalkanes use the halogen names at the start.
- E.g. Fluoromethane.
- E.g. Chloromethane.
- E.g. Bromomethane.
- E.g. Iodomethane.
Properties of halogenoalkanes
- Halogenoalkanes are polar molecules and contain polar bonds.
- The polar bonds are important in their reactions.
- Because halogens are more electronegative than carbon, the carbon atoms carry a partial positive charge and the halogen atoms carry a partial negative charge.
- Halogenoalkanes undergo substitution reactions with ammonia, hydroxide ions, and cyanide ions.
Nucleophiles and electrophiles
- A nucleophile is a molecule that is attracted to a nucleus.
- Nuclei have positive charges, so nucleophiles tend to be negatively charged.
- Molecules with lone pairs are also nucleophilic.
- An electrophile is a molecule that is attracted to a pair of electrons.
- Electrons have negative charges, so electrophiles tend to be positively charged.
Test yourself on Properties of Haloalkanes
What control halogenoalkanes' reactivity?
Halogenoalkanes tend to be involved in what type of reactions?