Please enable JavaScript.

Coggle requires JavaScript to display documents.

BONDING (Polarity (Predicting polarity of bonds (We can predict the…

- - - - In this experiment the CuCrO4 is put at the bottom of a U-tube. The solution above the CuCrO4 is originally colourless. As electricity is applied, the colour shifts up the tubes as the two different ions migrate to their respective electrodes
- - - - General formula: AX3
        Bond pairs: 3
        Lone pairs: 0
        Bond angle: 120
        Example: BF3
    - - General formula: AX5
        Bond pairs: 5
        Lone pairs: 0
        Bond angles: 120 + 90
        Eg: PCl5
    - - General formula: AX2
        Bond pairs: 2
        Lone pairs: none
        Bond angles: 180
        Example: CO2
    - - General formula: AX4
        Bond pairs: 4
        Lone pairs: 0
        Bond angle 109.5
        Eg: CH4
    - - General formula: AX6
        Bond pairs: 6
        Lone pairs 0
        Bond angle: 90
        Eg: SF6
    - - General formula: AX2
        Bond pairs: 2
        Lone pairs: 2
        Bond angle: 104.5
        Example: H2O
    - - General formula: AX3
        Bond pairs: 3
        Lone pairs: 1
        Bond angles: 107
        Example: NH3
    - - General formula: AX4
        Bond pairs: 4
        Lone pairs 2
        Bond angle:90
        Eg: XeF4
  - - - Weak IMFs that occur when temporary dipoles cause induced dipoles in neighbouring molecules
      - The more electrons in the molecule and the longer the molecule, the stronger the VDW force
      - all substances have VDW forces
    - - Electrostatic attractions between oppositely charged permanent dipoles of neighbouring molecules
      - stronger than VDW, weaker than hydrogen bonding
    - - Occurs when a (δ+) H atom from a covalent bond with F, N or O forms an electrostatic attraction with a lone electron pair on a neighbouring molecule
      - Substances with hydrogen bonds have higher melting points because extra energy is needed to break these bonds
      - Strongest of all IMFs
- - - - Graphite:
      - Silicon Dioxide:
      - Diamond:
- - - - The charge on an aluminium ion is 3+ because it has to lose three electrons to achieve a full outer shell
      - The charge on a nitride ion is 3- because it has to gain three electrons to achieve a full outer shell