Bonding Flashcards
Ionic bonding
- electrostatic attraction
- between oppositely charged ions
Covalent bond
- electrostatic attraction
- between shared pair of electrons
- and nuclei of bonded atoms
Ionic lattice mpt
- electrostatic forces acting in all directions
- lots of energy required to overcome bonds
- high mpt and bpt
Ionic lattice conduction
- solid- ions held in fixed position
- no mobile charge carriers
- liquid- ions are mobile
- able to conduct
Ionic lattice solubility
- greater the ionic charge the less soluble an ionic compound
- water can overcome ionic bonds
- attracted to polar ions
Dative covalent bond
- one atoms donates lone pair of electrons
- electrostatic attraction between shared pair of electrons
- and nuclei of bonded atoms
Draw N2
- triple bond between
- lone pair on each
Draw H2CO
- double bond between CO
- single between CH
Draw NH3BF3
- dative bond between N and B
Draw NH4+
- dative covalent bond
- 1+ charge
Simple molecular mpt and bpt
- only have induced dipole-dipole forces
- weak
- require little energy to overcome
- low mpt and bpt
Simple molecular conduction
- no mobile charge carrier, ions or electrons
- can’t carry charge
Simple molecular solubility
soluble in non-polar solvents
Giant covalent structure examples
- Si8
- graphite
- diamond
- graphene
- silicon dioxide SiO2
Giant covalent mpt and bpt
- high
- large number of covalent bonds
- large amount of energy to overcome
Giant covalent conductivity
- graphite and graphene can
- delocalised electrons
- free to carry charge
Electron pair repulsion theory
- electron pair repel each other round the central atom
- depends on number and type of pairs
- lone pairs repel more than bonded
Two bonded pairs
linear
180°
Three bonded pairs
Trigonal planar
120°
Four bonded pairs
Tetrahedral
109.5°
Five bonded pairs
Trigonal bipyramidal
120° and 90°
Six bonded pairs
90°
2 bonded pairs and 1 lone pairs
trigonal pyramidal
107°
2 bonded pairs and 2 lone pairs
angular(bent)
104.5°
Metallic bond
electrostatic attraction between delocalised electrons and positive metal cations
Metallic lattice mpt and bpt
- strong metallic bonds
- requires lots of energy to overcome
- very high mpt and bpt
Metallic lattice conductivity
- sea of delocalised electrons
- free to carry charge
Metallic properties
- malleable- non directional and exists in all directions
- ductile- independent of shape
Electronegativity
ability of an atom of an element to attract the shared pair of electrons in a covalent bond
Induced dipole-dipole interactions
- movement of electrons generates instantaneous dipole
- dipole induces others in neighbouring atoms
- generates weak temporary forces of attraction
Hydrogen bonding
- strong electrostatic attraction between polar molecules
- contain hydrogen
- covalently bonded to F,O and N
- have high electronegativity
Draw hydrogen bonding in water
Water properties
- ice is less dense than water(interlocking hexagonal rings)
- high mpt and bpt