3U Nomenclature Half
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All things have names, chemical compounds included. But whereas two
people can have the same name, no two chemicals can have the same
name.
The system of chemical nomenclature will allow you to give any chemical
its proper name and you will also be able to write the correct chemical
formula.
Elements
• Most elements do not exist in nature in their pure form, as elements. Gold,
Silver, and Platinum are three metals that can be found in the Earth’s crust
as elements. They are called precious elements because their occurrence
is so rare.
• There are only 90 naturally occurring elements. Most of these elements
are found in nature, only as compounds. Elements combine in may
different ways to form the astonishing variety of natural and synthetic
compounds that you see and use everyday.
• Some elements consist of more than one atom in their natural state.
These elements are called
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• Based on their physical properties, compounds can be classified into two
groups:
• Ionic compounds and covalent compounds display distinct physical
properties because of chemical bonding.
• Bonding involves
• Usually the formation of a bond between atoms
han either of the two atoms on their own.
Naming Ions
• Naming monoatomic cations
To name a monoatomic cation
Be2+ is called the
• Naming monoatomic anions
To name a monoatomic anion,
You can also include the word ion, but it is not
necessary.
N3- is called
3U Nomenclature Half
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All of the transition elements form
To name a transition metal, write the name of the element then
. Follow that with the word ion.
1+
Fe is the
Fe2+ is the
Fe3+ is the
Polyatomic Ions
• Polyatomic Ions are tightly bound groups of atoms that behave as a unit.
• Use the chart provided to name a polyatomic ion.
(PO4)3- is the
(ClO2)- is the
Naming Ionic Compounds
Monoatomic or simple ions
• Single atoms that have lost or gained one or more electrons
• Form binary ionic compounds (2 simple ions)
• Consist of
• Eg. Sodium + chlorine
Na+ Cl•
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The total charge must be
Do not write charges in your final answer
Writing Formulas for Ionic Compounds
• In binary ionic compounds, the total number of positive charges must
equal the total number of negative charges. Basically, the overall charge
must be zero.
• When writing binary ionic formulas, the cation always goes first.
• K1+ and Br 1• Ca2+ and S2• Ca2+ and Cl1• Na1+ and P3• Fe3+ and O2Writing Formulas from Names
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. You can
determine the charge based on their position on the periodic table;
Group 1 is 1+
- Group 5 is 3Group 2 is 2+
- Group 6 is 2Group 3 is 3+
- Group 7 is 1Group 4 is + or – 4
- Group 8 is 0
• Once you have the symbols with the charges,
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Sodium Oxide
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3U Nomenclature Half
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Calcium Phosphide
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• Iron (III) Sulfide
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• Calcium Nitrate
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Naming Ionic Compounds
• A compound is an inorganic compound that contains two elements.
• Binary compounds may contain
.
These would be binary ionic compounds.
• To name a binary ionic compound, name the
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CaS
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Calcium ion
Sulfide ion
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Beryllium ion
Chloride ion
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BeCl2
Multivalent Compounds
• The transition metals have
that will make them stable
• Use a
charge (Stock naming system).
• Eg.
Iron (II) oxide
Iron (III) oxide
Stock versus Classical
Formula
Stock Name
+
• Cu
copper(I) ion
• Cu2+ copper(II) ion
• Fe2+ iron(II) ion
• Fe3+ iron(III) ion
after the cation to specify its
FeO
Fe2O3
Classical Name
Cuprous ion
Cupric ion
Ferrous ion
Ferric ion
Polyatomic Compounds
• Identify the cation and the anion. (Use the polyatomic chart to identify the
polyatomic ion).
• Mg(NO3)2
• Magnesium ion
• Nitrate ion
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3U Nomenclature Half
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(NH4)2(CO3)
• Ammonium ion
• Carbonate ion
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Fe3(PO4)
• Iron (I) ion
• Phosphate ion
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Naming Molecular Compounds
• Use prefixes to specify number of atoms of each element in the molecule
• Second element ends with “-ide”
• No charges used in formula
• The prefix “mono-” should not be used on the first element
• mono
• di
• tri
• tetra
• penta
• hexa
• hepta
• octa
• nona
• deca
• The prefix “mono” is attached to the name of the second element in the
molecule when there is only one atom of that element present.
• It is not used in the name if the first element if there is only one atom of
that element present.
• N2O5
• 2 N is
• 5 O is
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• SF6
• 1 S is monosulfur, except it is first, so just sulfur
• 6 F is hexafluoride
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