VSPER theory

Question 1

’/;what is a domain

Answer 1

a bond (single, double, triple) or a lone pair of electrons on CA

Question 2

what is the formula charge equation

Answer 2

FC= V- N - (b/2)

fc= formal charge
v= # valence e-
b= # bonding e-
n= # non-bonding e-

Question 3

what is a formula charge

Answer 3

charge assigned to an atom in a molecule, the charge an atom involved in a chemical bond would have if e- were shared equally

Question 4

what are the rules for formal charges

Answer 4

1. sum of all fc’s must equal to overall charge of a molecule and/or polyatomic ion
2. most stable lewis structure wants fc’s to be as close to zero as possible
3. assign negative fc’s to the more electronegative atom of thebtwo that form a bond

Question 5

when is it polar or non-polar with electronegativity

Answer 5

0-0.4, non-polar
0.5-1.7, polar covalent
1.8-> ionic bond

Question 6

what properties do EN and polarity affect

Answer 6

• melting point
• boiling point
• solubility
• chemical reactivity
• density (for crystals)

Question 7

how do you determine polarity

Answer 7

1. draw lewis structure
2. use VSPER theory to determine 3D geometry
3. identify EN of each atom and determine the partial charges
4. draw bond dipoles and asses potential symmetry

Question 8

what is the distinction between bond dipole and net dipole (molecular dipole moment)

Answer 8

• bond dipole is asymmetric charge distribution between two bonded atoms with unequal EN
• net dipole (molecular dipole moment) is 3D sum of all the dipoles in a molecule