Molecular Polarity

Question 1

Electronegativity

Answer 1

is the measure of the amount of attraction that an atom is able to exert upon a shared electron pair within a chemical bond.

Question 2

VSEPR

Answer 2

Valence Shell Electron Pair Repulsion theory.
lone pair : lone pair repulsion - Strongest.
lone pair : bonding pair repulsion - Intermediary.
bonding pair : bonding pair repulsion - weakest.

Question 3

Bonding angles

Answer 3

angular - 104.5 degrees, e.g water molecule.
pyramidal - 107.3 degrees e.g ammonia
tetrahedral - 109 degrees e.g methane
diatomic molecule - 180 degrees e.g HF, HCl, HBr.
trigonal planar - 120 degrees e.g Bf3

Question 4

Molecular shapes and polarity

Answer 4

All angular shapes that have polar bonds will be polar overall.
All pyramidal molecules that have polar bonds will be overall polar.
tetrahedral molecules will be non polar due to symmetry.