Final Review

Question 1

Formal charge

Answer 1

FC = V - N - (B/2)

Where V is the number of valence electrons of the atom in isolation (atom in ground state)

N is the number of non-bonding electrons on this atom in the molecule

B is the total number of electrons shared in bonds with other atoms in the molecule

Example:

Question 2

London Dispersion forces

Answer 2

temporary dipoles - very weak forces (also called van der waals)

Question 3

Dipole-Dipole force

Answer 3

between the positive end of a polar molecule and the negative end of another polar molecule

Question 4

hydrogen bond

Answer 4

between the hydrogen attached to an electronegative atom and an electronegative atom of a different molecule

Question 5

ion-dipole forces

Answer 5

between the partial charge of a polar molecule and an atom that carries a charge

Question 6

ionic bond

Answer 6

between a positively charged atom and a negatively charged atom

Question 7

Hydrophobic effect

Answer 7

The observed tendency of nonpolar substances to aggregate in aqueous solution and exclude water molecules. This occurs because interactions between hydrophobic molecules allow the water molecules to bond more freely, increasing the entropy of the system

Question 8

Why is water a universal solvent

Answer 8

Water is polar.

It dissociates salts by separating cations and anions and forms new interactions between the water and ions