Naming Compounds
319-1 (II) name and write formulas
o some common ionic compounds
(both binary and complex), using
the periodic table, a list of ions,
and appropriate nomenclature for
metal and non-metal ions
Name the Following Binary Ionic
Compounds
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NaCl
MgO
Al4C3
Li2O
Mg3N2
CaS
AlCl3
• Try the worksheet on your own!
Metals with more than one
charge
• Many metals can form more than one cation,
with nearly all transition metals (the elements in
Groups 3 -12 in the periodic table) being able to
form more than one cation.
• For example, iron can form the cations Fe2+ and
Fe3+. Given the formula of an ionic compound,
you can use the reverse cross-over method to
determine the charge on the cation.
Reverse Cross-Over Method
• You can reverse the cross-over method to find
the charge for the cations in a compound.
Cu2S
Fe2O3
PbO2* Remember that O is always -2, so lead
must be +4
NiCl2
CrN * Nitrogen is -3, so Cr must be +3
HgO * Remember that O is always -2, so Hg must
be +2
Multivalent Elements
• There are two ways to name the cation of
a transition element (an element with more
than one charge). One way, is called the
classical method.
Classical Method
• It is based on Latin names for metals that
form more than one ion.
• The Latin name for iron is ferrum
• The Latin name for copper is cuprum
• The Latin name for lead is plumbum
• The –um on the end is dropped and the
ending “ous” is used for the lower charge
and “ic” for the higher charge.
• Fill in the following table:
Element
iron
Latin
Name
ferrum
Ion with
Ion with larger
lower
charge
charge
ferrous Fe+2 ferric
Fe+3
cuprum
Cu+
Cu+2
plumbum
Pb+2
Pb+4
Stock System
• The second, more current way to
distinguish between cations was invented
by German chemist, Alfred Stock.
• In the stock system, you use the English
name of the element. The charge of the
cation is written using a Roman numeral
after the name of the metal.
Copy the following table.
Formula
FeCl3
Classical
System
ferric chloride
FeO
ferrous oxide
Cu2S
cuprous sulfide
PbO2
plumbic oxide
Stock System
iron (lll) chloride
• The Stock System is only used for metals
that have more than one type of cation.
Therefore, you do not have to use it for
elements in Group 1, 2. Mainly the Stock
System is used for the middle elements.
• Write the chemical formula for the
following compound:
• copper (l) oxide
• Cu+1O-2
• Cu2O
• Write the chemical formula for the following
compounds.
• copper (l) oxide
• lead (lV) bromide
• iron (lll) sulfide
• nickel (lll) fluoride
• manganese (lV) sulfide
* You will only have to know these for the test, I
will not ask you for any that you have not seen.
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P. 113
#9 & 10
P. 115
#1&2
P. 117
#11 & 12
P. 117
#4 & 5