Writing Chemical Names and Formulas: A Review

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Whats in a name? That which we call a rose, by
any other name, would smell as sweet.
William Shakespeare Romeo Juliet
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Naming Chemical Compounds
Ionic Compounds
Covalent Compounds
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Classifying Compounds
The system for naming an ionic compound is
different from that for naming a covalent
compound, so before a compound can be named, it
must be classified as ionic or covalent.
Heres a simple test
Is there a metal present?

• If the answer is yes, use the system for naming
  ionic compounds.
• If the answer is no, use the system for naming
  covalent compounds.

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Naming Ionic Compounds

• Name the two elements
• Change the second one so that it ends in -ide
• LikeChloride, Sulfide, Oxide, Bromide,
  Phosphide, etc.

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Examples

• MgCl2
• NaF
• AlI3
• CaO
• Zn3P2
• GaN

• Magnesium Chloride
• Sodium Flouride
• Aluminum Iodide
• Calcium Oxide
• Zinc Phosphide
• Gallium Nitride

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Unfortunately
Its never quite that simple
Some metals form more than one ion.

• Add a Roman numeral to the name to indicate the
  charge
• Fe2 is called iron (II) and
• Fe3 is called iron (III)

• Assume a Roman numeral is required for any metal
  except
• metals in groups 1 and 2 on the periodic table
• aluminum, cadmium, silver, and zinc

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Duplicitous Metals

• Common metals that make more than 1 ion

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The Tricky Bits

• The tricky part is figuring out which ion charge
  the metal is using.
• Use the non-metal to figure this out.

• oxygen is 2-
• 2 of them is 4-
• so one Pb must be 4
• lead (IV) oxide

PbO2
Total charge must be zero
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Polyatomic Ions

• Sometimes the metal is not with a non-metal
• There are other negative ions
• They are composed of many non-metals bonded
  together
• The collection has an overall negative charge
• There are lots of these but a few are very common
• Heres a brief list of the most common

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Common Combined Ions
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Naming with PAI

• Put the two names together with no changes
• Remember the part about metals with more than one
  charge

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Naming Covalent Compounds

• Put the two names together
• Change the second one to end in ide
• Attach greek prefixes to show how many

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Naming Covalent Compounds
Prefixes
Often not used on first element (but not wrong
either)
When a prefix is added to oxide, the o or a is
often dropped like pentoxide or nonoxide
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Some Examples
N2S4
dinitrogen tetrasulfide
NI3
nitrogen triiodide
XeF6
xenon hexafluoride
P4O10
tetraphosphorous decoxide
P2O5
diphosphorus pentoxide
IF7
Iodine heptafluoride
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A Little Review/Practice
Na2CO3
sodium carbonate
NH4Cl
ammonium chloride
metal present ? ionic ? no prefixes Na ? group I
? no Roman numeral
NH4 ? polyatomic ion present ? ionic ? no
prefixes
N2O
dinitrogen monoxide
CoI3
cobalt (III) iodide
two nonmetals ? covalent ? use prefixes
metal present ? ionic ? no prefixes Co ? not
group I, II, etc. ? add Roman numeral (I is 1-,
total is 3-, Co must be 3)
K2O
potassium oxide
PI3
phosphorus triiodide
metal present ? ionic ? no prefixes K ? group I
? no Roman numeral
two nonmetals ? covalent ? use prefixes
SiF4
silicon tetrafluoride
Cu3PO4
copper (I) phosphate
two nonmetals ? covalent ? use prefixes
metal present ? ionic ? no prefixes Cu ? not
group I, II, etc. ? add Roman numeral (PO4 is 3-,
each Cu must be 1)
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You are now an expert at

• Chemical
• Nomenclature