1. 9.6 – NOTES Alkanes

2. Naming covalent compounds that are not hydrocarbons
determine the name of the first element
If there are no subscripts on the symbol, name the element as it is
If there is a subscript on the first symbol, put the prefix associated with the number in front of the name
2 – di 3 – tri 4 – tetra 5 – penta
6 – hexa 7 – hepta 8 – octa 9 – nona 10 - deca

3. Determine the name of the second element
Look at the second element in the compound and determine how many atoms of that element are present.
Put the prefix associated with the number in front of the element name. The prefixes are the same as the first part, only you now use mono to show that one atom is present
1 – mono 2 – di 3 – tri 4 – tetra 5 – penta
6 – hexa 7 – hepta 8 – octa 9 – nona 10 - deca
Change the ending of the second element to –ide
Oxygen becomes oxide, phosphorus becomes phosphide, etc.

4. Phosphorus Pentachloride
Examples
N2O5
Dinitrogen Pentoxide
BF3
Boron Trifluoride CO
Carbon Monoxide
H2O
Dihydrogen Monoxide
SBr6
Sulfur Hexabromide
PCl5
Phosphorus Pentachloride

5. Special Compounds: A few compounds do not use this naming system
Special Compounds: A few compounds do not use this naming system. Be familiar with these formulas and names
CH4
Methane
NH3
Ammonia

6. Modeling Alkanes
Two kinds of models
Ball and stick models
Balls are atoms and sticks are covalent bonds. Useful to show geometry, but bonds are not actually sticks.
Ex. CH4

7. Space-filling model
Atoms are in contact with each other, and this model is more accurate
Ex.
CH4
Tetrahedron
Pyramid shaped molecule with a triangle base

8. Molecular formula Condensed formula
Specifies how many of each atom types you have, doesn’t give any idea of molecules shape
Ex. CH4, C2H6, C3H8
Condensed formula
Show how atoms are arranged in a molecule, not just their number of atoms present
More useful
Examples:
 Structural
(Draw here)
Condensed CH4 CH3CH3 CH3CH2CH3

9. Alkanes
Simplest hydrocarbon, only has C+H, all single bonds
General formula for alkanes is CnH(2n+2), where n = the number of carbons.
Prefixes for hydrocarbons
1=meth 2=eth 3 = prop 4=but 5=pent
6 = hex 7=hept 8=oct 9=non 10=dec
Naming Alkanes
Count the number of carbons present and find the appropriate prefix
Put the ending – ane after the prefix

10. Examples
C2H6
Ethane
C9H20
Nonane