UNIT 6 BONDING AND NOMENCLATURE

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UNIT 6 BONDING AND NOMENCLATURE

• LESSON 3
• NAMING COMPOUNDS

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Chemist name compounds according to the atoms and
bonds that compose the compound.

• NAMING COMPOUNDS

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Naming Ionic Compounds

• Name the cation first, then anion
• Monatomic cation name of the element
• Ca2 calcium
• Monatomic anion root -ide
• Cl- chloride
• CaCl2 calcium chloride

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Naming Ionic Compounds
(Metals with multiple oxidation states)

• some metals can form more than one charge
  (usually the transition metals)
• use a Roman numeral in their name
• PbCl2 use the anion to find the charge on the
  cation (chloride is always 1-)
• Pb2 is the lead (II) cation
• PbCl2 lead (II) chloride

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Practice by writing the formula or name as
required

• Iron (II) Phosphate
• Tin (II) Fluoride
• (sometimes called Stannous)
• Potassium Sulfide
• Ammonium Chromate
• MgSO4
• FeCl3

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Naming and Writing Formulas for Molecular
Compounds
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Molecular compounds are

• made of just nonmetals
• smallest piece is a molecule
• cant be held together by opposite charge
  attraction
• cant use charges to figure out how many of each
  atom(there are no charges)

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Molecular compounds - Formulas are easy!

• Ionic compounds use charges to determine how many
  of each.
• You have to figure out charges.
• May need to criss-cross numbers.
• Molecular compounds the name tells you the
  number of atoms.
• Uses prefixes to tell you the exact number of
  each element present!

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Prefixes

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

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Write formulas for these

• diphosphorus pentoxide
• tetraiodine nonoxide
• sulfur hexafluoride
• nitrogen trioxide
• carbon tetrahydride
• phosphorus trifluoride
• aluminum chloride

(Ionic compound)
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Naming Molecular Compounds

• To write the name
• 1. 1st element Prefix name (least
• electronegative).
• 2. 2nd element Prefix name (more
• electronegative) change ending
• to -ide
• One exception - we dont write mono if there is
  only one of the first element.
• Normally, we do not have double vowels when
  writing names (oa oo)

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Practice by naming these
dinitrogen monoxide(also called nitrous oxide
or laughing gas)

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

nitrogen dioxide
dichlorine heptoxide
carbon tetrabromide
carbon dioxide
(This one will not use prefixes, since it is an
ionic compound!)
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Naming Hydrates
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Naming Hydrates

• Hydrates are ionic compounds that absorb water
  into their solid structures.
• Anhydrous are ionic compounds that are free of
  water.
• The name of the hydrated compound must reflect
  how many water molecules are attached (use
  prefixes)

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Practice Naming Hydrates

• CuSO4 ? 5H2O
• Copper II Sulfate pentahydrate
• Fe PO4 ? 4H2O
• Iron III Phosphate tetrahydrate

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Helpful to remember...

• 1. In an ionic compound, the net ionic charge is
  zero (criss-cross method)
• 2. An -ide ending generally indicates a binary
  compound
• 3. An -ite or -ate ending means there is a
  polyatomic ion that has oxygen
• 4. Prefixes generally mean molecular they show
  the number of each atom

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Helpful to remember...

• 5. A Roman numeral after the name of a cation is
  the ionic charge of the cation