2.8 Naming Inorganic
Compounds
• Cations formed from a metal have the same name as the
metal
• Metal ions with more than 1 charge:
Examples:
Cu+ = copper (I) (old: cuprous)
Pb+2 = lead (II) (old: plumbous)
Cu+2 = copper (II) (old: cupric)
Pb+4 = lead (IV) (old: plumbic)
Fe+2 = iron (II) (old: ferrous)
Sn+2 = tin (II) (old: stannous)
Fe+3 = iron (III) (old: ferric)
Sn+4 = tin (IV) (old: stannic)
Mn+2 = manganese (II) (old: manganous)
Mn+7 = manganese (VII) (old: manganic)
• Cations formed from non-metals end in -ium
Example: NH4+ ammonium ion.
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• Monatomic anions (with only one atom) end in -ide
Exceptions:
Example: Cl- is chloride ion
hydroxide (OH-), cyanide (CN-),
peroxide
(O22-)
• Polyatomic anions (with many atoms) containing oxygen
end in -ate or -ite
(The one with more oxygen ends in -ate)
Examples: NO3- is nitrate, NO2- is nitrite
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• Polyatomic anions containing oxygen with more than
two members in the series are named as follows (in
order of decreasing oxygen):
per-….-ate
-ate
-ite
hypo-….-ite
Text, P. 64
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• Polyatomic anions containing oxygen with additional
hydrogens:
add “hydrogen” or “bi-” (one H)
“dihydrogen” (two H), etc., to the name as follows:
CO32- is the carbonate anion
HCO3- is the hydrogen carbonate (or bicarbonate) anion
PO4 -3 is the phosphate anion
HPO4-2 is the hydrogen phosphate anion
H2PO4- is the dihydrogen phosphate anion
Note that the (-) charge decreases with each H that is
added
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Names and Formulas for Acids
• Acids have the general form HX
• The names of acids are related to the names of anions (X):
-ide becomes hydro-….-ic acid
-ate becomes -ic acid
-ite becomes -ous acid
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Text, P. 61
Names and Formulas of Binary
Molecular Compounds
• Binary molecular compounds are composed of 2
nonmetals
• The most metallic element is usually written first
(farthest left on the periodic table)
• Exception: NH3
• If both elements are in the same group, the lower one
is written first
• Greek prefixes are used to indicate the number of atoms
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Text, P. 62
Use a prefix to state how many of each atom
are in the formula
Don’t use “mono” for 1st element
When adding a prefix, the “ao” combination
is truncated
“tetroxide”
“heptoxide”