Bonding Flashcards
Define ionic bond.
A type of chemical bond formed by the complete transfer of electrons to form ions of opposite charge which attract each other electrostatically.
Define electron affinity.
The energy released when 1 mole of electron is added to 1 mole of gaseous atoms to form 1 mole of anions.
Define lattice energy.
The energy required to separate 1 mole of ionic compound into its constituent ions in gaseous phase.
Define metallic bonding.
Metal cations surrounded by a sea of delocalised electrons with strong electrostatic forces of attraction between the delocalised electrons and metal cations.
What are sigma bonds ?
Bonds formed when orbitals overlap head to head. Single bonds.
What are pi bonds ?
Bonds formed when p orbitals overlap sideways. Only formed after a sigma bond.
Define resonance hybrid.
A structure that is in between 2 resonance structures and is more stable than any of the resonance structures.
Define resonance energy.
The difference in stability between the resonance hybrid and resonance structure.
Define dipole.
When there is a charge separation and there are 2 charges in a molecule.
Define dipole moment.
The degree to which a molecule is polarised.
What are ionic solids ?
Consist of positive and negative ions arranged alternatively in a crystal lattice held together by strong electrostatic forces of attraction.
State the properties of ionic solids.
- High m.p & b.p
- Electrical conductors only when liquid
- Hard & brittle
- Insoluble in non-polar solvents
- Soluble in polar solvents
What are metals ?
Consist of a lattice of cations with the valence electrons forming a sea of delocalised electrons with strong electrostatic forces of attraction between the delocalised electron cloud and the metal cations.
Define malleable.
Easily rolled into sheets or hammered into different shapes.
Define ductile.
Easily drawn into wires.
Define resonance structures.
A structure that shows how pi electrons are shared between multiple atoms.
1 Bond pair
0 Lone pair
Molecular shape: linear
Electron Geometry: linear
Bond angle 180
2 Bond pair
0 Lone pair
Molecular shape: linear
Electron geometry: linear
Bond angle: 180
1 Bond pair
1 Lone pair
Molecular shape: linear
Electron geometry: linear
Bond angle: 180
3 Bond pair
0 Lone pair
Molecular shape: trigonal planar
Electron geometry: trigonal planar
Bond angle: 120
2 Bond pairs
1 Lone pair
molecular shape: bent
electron geometry: trigonal planar
bond angle: <120
1 Bond pair
2 Lone pair
molecular shape: linear
electron geometry: trigonal planar
bond angle: 180
4 Bond pair
0 Lone pair
molecular shape: tetrahedral
electron geometry: tetrahedral
bond angle: 109.5
3 Bond pair
1 Lone pair
molecular shape: trigonal pyramidal
electron geometry: tetrahedral
bond angle: 107.3
