Final Exam Review Section 5

Question 1

Lattice energy

Answer 1

-The higher charge present on each ion the greater the lattice energy
-smaller the radius of atoms the higher the lattice energy
-1st rule takes precedent over 2nd rule

Question 1

Bond order

Answer 1

Corresponds to the number of bonds between 2 atoms (i.e. single, double or triple)
-Greater the Bond order the greater the bond strength

Question 2

Bond length

Answer 2

Distance between 2 atoms nucelli
1.Bond length will increase as radius of atoms increase
2.Bond length will increase as bond order decreases (i.e. single nond>double>triple)

Question 3

Bond Energy

Answer 3

Reflects how strong a bond is, directly related to bond order. How much energy required to break bond.
1. Greater bond energy than the shorter the bond length

Question 4

Octet Rule

Answer 4

Atom must have 8 electrons in its valence shell to be stable. each bond and Lone pair correspond to 2 electrons.

Question 5

Octet Rule exceptions

Answer 5

1. Hydrogen
   -only needs two electrons to obtain full outer shell and can be stable with 0
2. Boron & Beryllium
   -stable with fewer electrons Boron (6) Beryllium (4)
   3.Atoms with more than 8
   -any nonmetal in period 3 or higher

Question 6

Formal charge

Answer 6

FC = (# of valence electrons) - (# of dots) - (# of lines)

Question 7

Lewis structure process

Answer 7

1.Determine total number of valence electrons
2.Determine central atom (Most electropositive)
-never hydrogen
3.add valence electrons to central atom
4. connect via covalent bonds
5.Insert multiple bonds in necessary
6.Assign formal charges
7.Choose best structure
-Negative charge on more electronegative atom

Question 8

Bond energy equation

Answer 8

Hr = (sum of reactants) - (sum of products)
Breaking bonds is typically an endothermic reaction and requires energy.