1. Ionic vs Covalent Compounds
Lab 5.4
Ionic vs Covalent Compounds

2. Conductivity For a substance to conduct it must have:
1. Particles that are free to move
2. Charged Particles

3. Conductivity of Solutions Salt vs. Sugar
The particles must be charged.
The particles must be neutral (not charged).
Salt and Sugar both dissolve in water, forming clear solutions. During dissolving, the particles of the solid salt or sugar became free to move. So, while both have met that requirement of conductivity, only salt meets the 2nd requirement.

4. Solutions that Conducted
Name
Formula
Combination of Elements
Sodium chloride (salt)
NaCl
M-nm
Potassium bromide
KBr
Magnesium sulfide
MgS
Barium iodide
BaI2

5. Solutions that Conduct
Ionic Compounds:
Composed of metal and nonmetal elements
Composed of charged particles called ions
Ion = an atom that has become charged

6. Ions are free to move in the salt solution
Positive Ion
Negative Ion
Ionic bond: attraction between the oppositely charged ions
In the solid salt, there are charged particles-the ions, but they are not free to move
Dissolving
Ions are free to move in the salt solution

7. Dissolving an Ionic Compound
Watch the following animation:
Dissolving an ionic compound
Dissolving an ionic compound #2

8. The ionic bond that once held the oppositely charged ions together is now broken.
Na+ + + - + -
Cl- -
Water particles are not shown. Each ion is surrounded by many water particles, keeping them separate and no longer attracted to each other. - + + -

9. Naming Ionic Compounds
Metal name goes 1st with no change.
Nonmetal name is changed to an “-ide” ending.
Sodium chloride, NOT sodium chlorine
Aluminum oxide, NOT aluminum oxygen

10. Solutions that Don’t Conduct
Name
Formula
Combination of Elements
Sugar
C12H22O11
Nm-nm
Ammonia
NH3
Isopropynl
C3H8O
Carbon dioxide
CO2

11. Solutions that do NOT conduct
Covalent Compounds:
Composed of only nonmetal elements.
Composed of neutral particles called molecules.
Molecule = group of atoms bonded together that acts as a single unit (particle)

12. Molecules
Ammonia
(NH3)
Water
(H2O)

13. Each individual molecule is “intact”; the atoms are still bonded as a group.
The covalent bond between the nm atoms has not been broken.
NH3

14. Naming Covalent Compounds
Element listed first in the formula is named first with no change.
2nd element is changed to “-ide” ending AND is preceded by a prefix.
Carbon dioxide, NOT carbon oxide.
Carbon tetrachloride, NOT carbon chloride.

15. Molecular Nomenclature Prefixes
mono-
di-
tri-
tetra-
penta-
hexa-
hepta-
octa-
nona-
deca-
NUMBER 1 2 3 4 5 6 7 8 9 10