6.3 Naming Ionic
Compounds and
Writing Chemical
Formulas
Naming Ionic Compounds
• An ionic compound’s name must
distinguish it from other
compounds containing the same
element.
Binary Ionic Compounds
• Compound made from only two elements
• When naming a binary ionic compound, the
cation is first followed by the anion
• Anion suffix is changed to –ide.
– Ex: Sodium chloride
– Sodium is the metal (cation)
– Chloride is the nonmetal chlorine
Binary Ionic Compounds Practice
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CaBr2 – Calcium Bromide
MgO-Magnesium Oxide
Cs2S-Cesium Sulfide
Mg3N2-Magnesium Nitride
NaBr-Sodium Bromide
Li2S-Lithium Sulfide
Naming Metals With Multiple Ions
• Transition metals have the ability to
form more than one type of ion.
• We use Roman numerals in the name
of the ion to distinguish one from
another. The Roman numeral
indicates the charge on the ion.
–Ex: Copper (I) and Copper (II)
Ionic Compounds with Metals that Form
Multiple Ions
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Iron (III) Nitride-FeN
Copper (I) Oxide-Cu2O
Copper (II) Bromide-CuBr2
Lead (IV) Sulfide-PbS2
Chromium (II) Fluoride-CrF2
Polyatomic Ions
• Covalently bonded group of
atoms that has a positive or
negative charge and acts as a unit
• Prefix –poly means “many”
• Most are anions
• Look for compounds made of
more than two elements
Ionic Compounds with Polyatomic Ions
(Polyatomic Ion In Red)
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(NH4)2O-Ammonium
AlPO4-Aluminum Phosphate
Mg(C2H3O2)2-Magnesium Acetate
NaNO3-Sodium Nitrate
NaOH-Sodium Hydroxide
PRACTICE:
Naming Ionic Compounds
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CaCl2
CaO
Cu2S
Li2SO4
Rb3N
NaOH
FeBr2
MgOH2