1. Molecular Compounds
Covalent Bonds

2. Molecular Compounds Also called covalent compounds
A molecule is a neutral group of atoms that are held together by covalent bonds
The valence e- are shared by the atoms
Covalent bonding usually occurs between 2 non-metals
H2O, CO2, O2, NO

3. Naming Molecular Compounds
Use prefixes mono-
2 di-
3 tri-
4 tetra-
5 penta-
6 hexa-
7 hepta-
8 octa-
9 nona-
10 deca-

4. Examples Tetraphosphorous decoxide Dinitrogen trioxide
P4O10
N2O3
As2O5
OF2
Tetraphosphorous decoxide
Dinitrogen trioxide
Diarsenic pentoxide
Oxygen difluoride

5. Ionic or Covalent Ionic Covalent Ionic Covalent Ionic Ionic Covalent
Sodium Bromide
NaBr
CH4
Fe2O3
CO2
CaO
NH4Cl
SiCl4
Covalent
Carbon tetrahydride
Iron (III) oxide
Ionic
Covalent
Carbon dioxide
Ionic
Calcium oxide
Ionic
Ammonium chloride
Covalent
Silicon tetrachloride

6. Diatomic Molecules H2 O2 N2 Cl2 Br2 I2 F2 7 diatomic molecules
No noble gases
Halogens and N, O, H
They are all gases (not noble gases) except for Br and I
“Honcl brif”

7. Empirical Formula CH3O NaC4H6O2
A formula that represents the lowest integral ratio of atoms of the elements in a compound
C2H4, C3H6 and C4H8 all have the same empirical formula:
CH2
Examples
C2H6O2 
NaC4H6O2 
CH3O
NaC4H6O2

8. Naming Acids **only binary acids use “hydro”
Anion Acid Name Example -ide hydro—ic HCl hydrochloric acid -ite --ous HNO2 nitrous acid -ate --ic HNO3 nitric acid
**only binary acids use “hydro”

9. Try these. . . Sulfuric Acid Hydrofluoric Acid Phosphoric Acid
H2SO4 HF
H3PO4
H2SO3
H2CO3
HNO3
Hydrofluoric Acid
Phosphoric Acid
Sulfurous Acid
Carbonic Acid
Nitric Acid

10. More Practice. . . CaBr2 Cr(C2H3O2)3 BaSO4 Cu2S SF6 Calcium bromide
Chromium (III) acetate
Barium sulfate
Copper (I) sulfide
Sulfur hexafluoride
Cr(C2H3O2)3
BaSO4
Cu2S
SF6

11. More Practice. . . Chromium (III) oxalate Mercury (II) cyanide
Cr2(C2O4)3
Hg(CN)2
Cu(ClO4)2
ZnC4H4O6
Chromium (III) oxalate
Mercury (II) cyanide
Copper (II) perchlorate
Zinc tartrate

12. How to Calculate Molar Mass
The mass of a compound
In order to calculate molar mass (also called molecular weight) you add up the masses of each element in the compound
Be aware of subscript numbers that designate the amount of atoms per element
You get the masses from the periodic table
**be careful when rounding the mass

13. Examples 58.5 g/mol 18 g/mol 63 g/mol 261.3 g/mol NaCl H2O HNO3
Na = 23 g/mol
Cl = 35.5 g/mol
H2O
H = 1 g/mol (but there are 2) = 2 g/mol
O = 16 g/mol
HNO3
H = 1 g/mol
N = 14 g/mol
O = 16 g/mol (but there are 3) = 48 g/mol
Ba(NO3)2
Ba = g/mol
N = 14 g/mol (but there are 2) = 28 g/mol
O = 16 g/mol (but there are 6) = 96 g/mol
18 g/mol
63 g/mol
261.3 g/mol