Covalent Bonding Notes

1
Covalent Bonding Notes

• Formula writing and naming

2
Review

• Covalent bond forms between-
• two non-metals
• So there are never polyatomic ions!
• Electrons are-
• shared between the two elements

3
Two types of chemical formulas

• Empirical-
• is the simplest whole number ratio by which the
  elements are combined
• Molecular-
• the actual number of atoms in the molecule

4
Ex Sugar

• Molecular formula Empirical formula
• C6H12O6 Reduce? C H2O
• ACTUAL amt of atoms RATIO 121
• Covalent molecules are ALWAYS expressed in
  molecular formulas-----which means you NEVER
  reduce a covalent molecule

5
Naming

• Rules for naming are similar to ionic bonds
• Write the name of the first element from the
  periodic table
• Write the name of the second element drop the
  ending and add ide
• Use prefixes to represent the number of elements
  in a bond

6
(No Transcript)
7
Ex------- Name P2O6

• Phosphorous
• Phosphorus Oxide
• Diphosphorus Hexaoxide
• CHECK YOUR WORK
• 2 Ps 6 Os

8
Ex------ Name C3Br4

• Carbon
• Carbon Bromide
• Tricarbon Tetrabromide
• CHECK YOUR WORK
• 3 Cs 4 Brs

9
Ex----- SO2

• Sulfur
• Sulfur oxide
• Monosulfur dioxide
• The answer is wrong!!

10
Ex----- SO2

• Exception to rule 3-
• You dont use mono to start a name.
• Correct answer
• Sulfur dioxide
• 1 S 2 Os

11
Writing Formulas

• Write the symbol for the first element.
• Write the symbol for the second element.
• Write the prefixes as subscripts after the
  symbols.

12
Ex---dicarbon tetrasulfide

• C
• CS
• C2S4
• CHECK YOUR WORK
• di 2 carbons tetra 4 sulfurs

13
Ex---- tricarbon heptahydride

• C
• CH
• C3H7
• CHECK YOUR WORK
• Tri 3 carbons hepta 7 hydrogens

14
Ex---- carbon monoxide

• C
• CO
• CO
• Remember the exception- no name starts with
  mono. So if the first element doesnt have a
  prefix then the subscript is automatically 1.