4) INTERMOLECULAR FORCES Flashcards
Name the types of intermolecular forces
LDF’s
PDP - PDP
Hydrogen
What are intermolecular forces
Forces of attraction between molecules
What causes LDF’s
Uneven distribution of electrons within an atom or molecule
What is the relationship between LDF’s and number of electrons
The greater the number of electrons the stronger the LDF
What happens to LDF’s as you go across a period
There are more electrons
- therefore a stronger LDF
- therefore a higher MP & BP
What happens to LDF’s as you go across a period
There are more electrons
- therefore a stronger LDF
- therefore a higher MP & BP
When do PDP - PDP arises
Arises when an atom in one molecule with a partial positive charge (S+) attracts to another atom with a partial negative charge (S-)
Occurs between polar molecules
How does a hydrogen bond arise
H bonded to a F, O, N
What intermolecular causes unexpectedly high MP, BP and viscosity
Hydrogen bonding
How do polar bonds occur
Occur due to differences in electronegativity and unequal sharing of electrons. The differences electronegativity 0.5 & 1.5
What makes a polar molecule
- Polar bonds
- unsymmetrical
Put in order from weakest to strongest
Metallic PDP - PDP Ionic LDF's Hydrogen Covalent
LDF's PDP - PDP Hydrogen Metallic Ionic Covalent
Name the 3 forms of carbon and name there bonding and structure
Diamond (covalent network)
Graphite (covalent network)
Fullerenes (covalent molecular)
