Comparing Bonds & Intermolecular Forces
Intramolecular forces
- Intramolecular forces are forces within a molecule
- Ionic bonding is the electrostatic attraction between positive (cations) and negative (anions) ions in an ionic crystal lattice
- These ions are formed by transferring the electrons from one species to the other
- Covalent bonds are formed when the outer electrons of two atoms are shared
- Metallic bonding is the electrostatic attraction of positively charged metal ions and their delocalised electrons in a metal lattice
Intramolecular forces
The three types of intramolecular forces are ionic, covalent and metallic bonding
Intermolecular forces
- Intermolecular forces are forces between molecules and are also called van der Waals’ forces
- Permanent dipole - permanent dipole are the attractive forces between two neighbouring molecules with a permanent dipole
- Hydrogen bonds are a special type of permanent dipole - permanent dipole forces
- Instantaneous dipole - induced dipole (London dispersion) forces are the attractive forces between a temporary dipole and a neighbouring molecule with an induced dipole
Permanent dipoles as intermolecular forces
Permanent dipole - permanent dipole are the intermolecular forces that occur between two neighbouring molecules with a permanent dipole
Instantaneous dipoles as intermolecular forces
Instantaneous dipole - induced dipole (London dispersion) forces are the intermolecular forces that occur between a temporary dipole and a neighbouring molecule with an induced dipole
Hydrogen bonding as an intermolecular force
Hydrogen bonds are a special type of permanent dipole - permanent dipole forces
- In general, intramolecular forces are stronger than intermolecular forces
- The strengths of the types of bond or force are as follows:
The varying strengths of different types of bonds
In general, ionic bonding is the strongest force while instantaneous dipole - induced dipole is the weakest force
