Unit 1: Bonding (Notes) Flashcards
Boron exception
Boron is stable with 6e
Beryllium exception
Be is stable with
2e
4e
VSEPR Theory
Electrons repel each other which causes bending of certain branches of molecule
D: Electronegativity
A measure of how well atoms attract bonding electrons
Atomic size trend on the periodic table
Left (bigger) - Right (smaller)
Top (smaller) - Bottom (bigger)
E/n Difference
> 1.7
Ionic
E/n difference
<1.7
Polar covalent
E/n difference
= 0
Non polar covalent
D: Bond dipoles
Represent the distribution of charge within a bond
D: Molecular dipole
Represents overall charge distribution of molecule
Difference between inter and intramolecular forces
Intermolecular - forces between molecules
Intramolecular - bonds with molecule
DD force
- Only for polar molecules
- Dipole of one molecule aligns with the dipole of adjacent molecules
HB
- Strongest IMF
- H bonded with nitrogen, oxygen or fluorine
- H is attracted to lone pairs of other molecules
LDF
- Random motion of electrons causes them to bunch up = temporary dipole
- Weakest IMF
- Determined by # of electrons/protons
Melting and Boiling points
Stronger bond = Higher boiling and melting points
Solubility rule
Polar solute dissolves in polar solvent. Vice versa
5 Properties of covalent network bonding
- Hard
- Poor conductors
- Rigid structure
- High mp
- Strongest bond
6 Properties of metallic bonding
- Malleable
- Ductile
- Low to high mp
- Good conductors
- Crystal lattice
- Low e/n
3 Properties of ionic solids
- Solid at room temperature
- High bp
- Poor conductors as solids
2 Properties of molecular solids
- Low bp
2. LDF, DD, HB
List type of bonds from strongest to weakest
- Covalent network
- Covalent
- Ionic
- Metallic
List IMFs from strongest to weakest
- HB
- DD
- LDF
