Permanent Dipole-Permanent Dipole Forces- The permanent dipole of one molecule attracts the permanent dipole of another to form a weak permanent dipole-permanent dipole force.
van der Waals' Forces- Formed by the movement of electrons in their shells creating an uneven distribution of charge, and thus creating an instantaneous dipole across the molecule. This instantaneous dipole induces dipoles in surrounding molecules etc. The dipoles attract each other forming weak intermolecular forces.
- The more electrons, the larger the induced dipoles, the larger the attraction between molecules and the larger van der Waals' forces produced.
Hydrogen bonds- These form when an electron deficient H atom attracts a lone pair of electrons on an O or an N molecule. Hydrogen bonds only form between O-H and N-H.
- Ice is less dense than water as ice has an open lattice structure, holding the water molecules apart.
- Water has higher mp/bps than expected as hydrogen bonds must also be overcome.
Comments
No comments have yet been made