INTERMOLECULAR FORCES

Intermolecular Forces

Forces of attraction between molecules or between atoms of noble gases.

Ionisation

The reaction of a molecular substance with water to produce ions, such as HCl that ionises in water.

Dissociation

The splitting of an ionic compound into its ions when dissolved in water, where ions become free moving in solution.

Electrolyte

A substance that can conduct electricity due to the presence of free ions when molten or dissolved in solution.

London Forces

Weak forces of attraction that occur in non-polar simple covalent molecules and noble gases.

Dipole-Dipole Forces

Weak intermolecular forces between two polar molecules with different electronegativities.

Hydrogen Bonding

The strongest type of intermolecular forces occurring when hydrogen is bonded to N, O, or F and there is a lone pair.

Electrolytes Examples

Common examples include NaCl, HCl, H₂SO₄, and KBr when in aqueous or molten state.

Characteristics of Polar Molecules

They have polar bonds, an asymmetrical shape, and consist of different atoms.

Characteristics of Non-Polar Molecules

They have polar bonds but a symmetrical shape (tetrahedral, linear) and consist of the same atoms.

Strength of Ionic Bonds

Very strong forces with very high melting and boiling points.

Strength of Hydrogen Bonds

Strong forces with high melting and boiling points.

Strength of Dipole-Dipole Forces

Medium strength with moderate melting and boiling points.

Strength of London Forces

Weak forces with low melting and boiling points.