1. Chemical Bonding and Nomenclature
Adapted from Paul Surko

2. What is Bonding????????
Bonding, the way atoms are attracted to each other to form compounds, determines nearly all of the chemical properties we see. The number “8” is very important to chemical bonding.

3. What are Compounds?
Compounds are a combination of atoms bonded together. Bonding determines the chemical properties of the compound.

4. Ionic Bonding-Great with 8
All atoms want 8 valence electrons. Metals give up electrons to form positive ions (cations) and non-metal atoms will receive or take additional electrons to become negative ions (anions). IONS are charged particles.
Na becomes Na+
O becomes O-2
Cl becomes Cl-
Al becomes Al+3
N becomes N-3
Mg becomes Mg+2
The positive and negative ions are attracted to each other electrostatically.

5. Properties of Ionic Compounds
Made of cations and anions
Exist in crystalline structures (solids) at STP
High MPs and BPs
Conduct electricity in aqueous and molten states

6. Opposites Attract!

7. Putting Ions Together Na+ + Cl- = NaCl Ca+2 + Cl- = CaCl2
Ca+2 + O-2= CaO
Na+ + O-2 = Na2O
Al+3 + S-2 = Al2S3
Ca+2 + N-3 = Ca3N2
You try these!
Li+ + Br- =
LiBr
Mg+2 + F- =
MgF2
AlI3
Al+3 + I- =
NH4+ + PO4-3 =
(NH4)3PO4
Sr+2 + P-3 =
Sr3P2
Not NH43PO4
K+ + Cl- =
KCl

8. Nomenclature Naming of Ionic Compounds with TMs
Binary Compounds have two types of atoms (not diatomic which has only two atoms).
Metals (Groups I, II, and III) and Non-Metals
Metal _________ + Non-Metal _________ide
Sodium Chlorine Sodium Chloride NaCl
Metals (Transition Metals) and Non-Metals
Metal ______ +Roman Numeral (__) + Non-Metal ________ide
Iron III Bromine Iron (III) Bromide FeBr3 Compare with Iron (II) Bromide FeBr2

9. Nomenclature--Naming of Ionic Compounds with TM
Metals (Transition Metals) and Non-Metals Older System
Metal (Latin) _______ + ous or ic + Non-Metal ________ide
Ferrous Bromine Ferrous Bromide FeBr2 Compare with Ferric Bromide FeBr3

11. Let’s Practice! Name the following. CaF2 Calcium Flouride K2S
Potassium Sulfide
CoI2
Cobalt (II) Iodide or Cobaltous Iodide
SnF2
Tin (II) Flouride or Stannous Flouride
SnF4
Tin (IV) Flouride or Stannic Flouride
OF2
Oxygen diflouride
CuI2
Copper (II) Iodide or Cupric Iodide
CuI
Copper (I) Iodide or Cuprous Iodide
SO2
Sulfur dioxide
SrS
Strontium Sulfide
Lithium Bromide
LiBr

12. Polyatomic Ions (partial list from page 195 (193 2nd edition))
Ammonium……………...
Nitrate……………………
Permanganate…………. .
Chlorate…………………
Hydroxide……………….
Cyanide………………….
Sulfate…………………...
Carbonate……………….
Chromate………………..
Acetate…………………..
Phosphate……………….
NH4+
NO3-
MnO4-
ClO3-
OH-
CN-
SO4 2 -
CO32-
CrO42-
C2H3O2-
PO43-

13. Lets Practice! Na2CO3 Sodium carbonate KMnO4 Potassium permanganate
NaOH
Sodium hydroxide
CuSO4
Copper (II) sulfate or Cupric sulfate
Lead (II) chromate or Plubous chromate
PbCrO4
NH3
ammonia

14. The Covalent Bond
Atoms can form molecules by sharing electrons in the covalent bond. This is done only among non-metal atoms.

15. Properties of Covalent Compounds
Generally exist as liquids and gases at STP
NO crystalline structure
Low MPs and BPs
Do NOT conduct electricity

16. Lewis Structures-Octet Rule (All atoms want 8 electrons around them.)
Lewis came up with a way to draw valence electrons so that the bonding could be determined.

17. Rules to Write Lewis Structures
Write a skeleton molecule with the atom with highest bonding capacity in the middle
Find the number of electrons you have (valence e-'s)
Add surrounding atoms around central atom and for each bond, subtract 2 electrons from total for each bond
Add lone pairs of electrons to each of the surrounding atoms to satisfy the octet rule
Place any remaining electrons on the central atom
Note: Boron and Beryllium are highly electronegative atoms and can therefore be excluded from the octet rule

18. Let's Try it! H O H S Water H2O NB NB E
Water H2O
2 x 2 = 4 for Hydrogen 1 x 8 = 8 for Oxygen 4+8=12 needed electrons
12 N -
8 H
2 x 1 = 2 for Hydrogen 1 x 6 = 6 for Oxygen You have 8 available electrons -
4 B
4 NB
= 4 bonding electrons
H:O:H
8 – 4 = 4 non-bonding electrons ..
H:O:H ●● ..
H:O:H ●●

19. Let's Try it! H H N H S Ammonia NH3 NB NB E
Ammonia NH3
3 x 2 = 6 for Hydrogen 1 x 8 = 8 for Nitrogen 6+8=14 needed electrons
14 N -
8 H
3 x 1 = 3 for Hydrogen 1 x 5 = 5 for Nitrogen You have 8 available electrons -
6 B
2 NB
= 6 bonding electrons H
.. H:N:H
8 – 6 = 2 non-bonding electrons H H ..
H:N:H ●● ..
H:N:H ●●

20. Let's Try it! Carbon Dioxide CO2 S N H B NB E O C O
1 x 8 = 8 for Carbon 2 x 8 = 16 for Oxygen 8+16=24 needed electrons
24 N -
16 H
1 x 4 = 4 for Carbon 2 x 6 = 12 for Oxygen You have 16 available electrons -
8 B
8 NB
= 8 bonding electrons
16 – 8 = 8 non-bonding electrons
O::C::O
O::C::O ●● ●●
O::C::O ●● ●●

21. Let's Try it! O O C O Carbonate CO3-2 S NH B NB E
3 x 8 = 24 for Oxygen 1 x 8 = 8 for Carbon 24+8=32 needed electrons
32 N -
24 H
3 x 6 = 18 for Oxygen 1 x 4= 4 for Carbon You have more available e-'s -
8 B
16 NB
= 8 bonding electrons O
.. O::C:O
24 – 8 = 16 non-bonding electrons
.. :O:
.. :O:
O::C: O: ●● ●● -2
O::C: O: ●● ●●

22. Nomenclature of Covalently Bonded Compounds--Molecules
Non-Metals and Non-Metals
Use Prefixes such as mono, di, tri, tetra, penta, hexa, hepta, etc.
CO2 Carbon dioxide CO Carbon monoxide
PCl3 Phosphorus trichloride CCl4 Carbon tetrachloride
N2O5 Dinitrogen pentoxide CS2 Carbon disulfide

23. Intermolecular Forces
Intermolecular Forces: forces of attraction that exist between two molecules
Hydrogen Bonding: an IMF results from the attraction between hydrogen and a highly electronegative element like F, N, or O
Rather strong force
Responsible for water’s high surface tension, holding together DNA, and varying BPs and MPs

24. Intermolecular Forces
Dipole-Dipole Force: an IMF that exists between two polar molecules (hydrogen bonding is a special type of dipole-dipole force)
Rather strong
Used to predict MPs and BPs
Van der Waals Force: an IMF that exists between two nonpolar molecules
Very weak
Instanteous
Predicts the low MPs and BPs of nonpolar molecues

25. Forces between Ionic Solids
Electrostatic Forces: a force of attraction that exists between ionic compounds due to opposite charges
VERY strong
Responsible for high MPs and high BPs