SIMPLE
MOLECULAR
LATTICES
SIMPLE MOLECULAR
LATTICES
Fundamental crystalline structure in AS Level
chemistry, consisting of separate (discrete)
molecules arranged in a regular,repeating 3D
pattern.
1. KEY BONDING
FEATURES
Intramolecular Bonds : atoms inside each molecule are
held together by strong covalent bonds
Intermolecular Forces : Molecules are held together in the
lattice by relatively weak intermolecular forces ( such as
London forces, permanent dipole-dipole, or hydrogen
bonds)
2. CORE PHYSICAL
PROPERTIES
1. Low melting and boiling points : only the weak
intermolecular forces need to be broken to melt or boil
the substances; the strong covalent bonds remain
intact. Many are gases or liquids at room temperature
2.Non-conductors: They do not conduct electricity in
any state because they have no mobile charged
particles(no free electrons or ions) to carry a current.
3.Solubility :
Non-polar molecules (e.g I2) tend to be soluble in nonpolar solvents (like hexane) but insoluble in polar
solvents like water.
Polar molecules(e.g.sugar , NH3) may dissolve in water
if they can form hydrogen bonds with it.