Molecular Compounds

1
Molecular Compounds

• Writing Names and Formulas

2
Covalent Bonding / Compounds

• Compounds in which the electronegativity
  difference is less than 2.0
• Between a nonmetal and nonmetal
• Cant be held together because of opposite
  charges
• Cant use charges to figure out how many of each
  atom

3
Covalent Bonding

• Smallest piece of a covalently bonded compound is
  a molecule
• Electrons are shared between atoms in bond

4
Differences between ionic and covalent bonding

• Ionic bonding
• electron is stolen
• high electronegativity difference
• between metal nonmetal
• Formation of crystal structure
• think proportions of atoms in formula unit
  NaCl 11

5
Molecules are easier to name and work with

• Ionic compounds use charges to determine how many
  of each.
• Have to figure out charges
• Have to figure out numbers
• Molecular compounds name tells you the number of
  atoms.

6
Naming

• The second part of all names end with -ide
• Prefixes are used to indicate number of each atom

7
Prefixes

• 1 mono-
• 2 di-
• 3 tri-
• 4 tetra-
• 5 penta-
• 6 hexa-
• 7 hepta-
• 8 octa-

• 9 nona-
• 10 deca-

8
Naming Continued

• To write the namewrite two words
• Prefix-name Prefix-name ide
• One exception is we dont write mono- if there is
  only one of the first element.
• No double vowels when writing names
• (oa oo)

9
Name These

• N2O
• NO2
• Cl2O7
• CBr4
• CO2
• BaCl2
• H2O

• Dinitrogen monoxide
• Nitrogen dioxide
• Dichlorine heptoxide
• Carbon tetrabromide
• Carbon dioxide
• Barium chloride
• Dihydrogen monoxide

10
Write Formulas for These

• Diphosphorous pentoxide
• Tetraiodine monoxide
• Sulfur hexaflouride
• Nitrogen trioxide
• Carbon tetrahydride
• Phosphorous trifluoride
• Aluminum chloride

• P2O5
• I4O
• SF6
• NO3
• CH4
• PF3
• AlCl3

11
Lewis Dot Structure(AKA Electron Dot Structure)

• Write the symbol for each atom and show each of
  their valence electrons as dots (ignore all
  electrons below valence shell)

Cl2

2. The number of electrons before you combine the
atoms should equal number you have after.
Cl