Shapes Of Molecules And Intermolecular Forces Ch. 7 Flashcards
What happens to electron pairs in outer shells
They repel each other and end up as far apart as geometrically possible.
Which are stronger lone or bond pairs
Lone pairs
Rule for electron repulsion theory
Lone pair:lone pair repulsion > lone pair:bond pair repulsion> bond pair:bond pair repulsion
Linear have a bond angle of
180°
Trigonal planar have a bond angle of
120°
Tetrahedral has a bond angle of
109.5°
Pyramidal has a bond angle of
107°
V-Shaped has a bond angle of
104.5°
Two bond pairs, no lone pairs
Linear
Three bond pairs, no lone pairs
Trigonal planar
4 bond pairs, no lone pairs
Tetrahedral
Three bond pairs, one lone pair
Pyramidal
Two bond pairs, two lone pairs
V-Shaped
What two criteria are there for a molecule to be polar
Polar covalent bonds, no symmetry
Which shapes of molecules are described to be non-polar and why
Linear, trigonal planar, tetrahedral due to their symmetry
What is intramolecular bonding
The forces within the molecule holding the atoms together
What are intermolecular forces
Forces between molecules
What are the three types of intermolecular forces from strongest to weakest
Hydrogen bonds, dipole dipole forces, van der Waals’ forces
Define hydrogen bonding
special type of dipole dipole forces that only occurs between hydrogen and small, highly electronegative elements such as O, N and F.
What is determined by the intermolecular forces
Boiling point (H-bonds = higher, van der Waals’ = Lower)
