Chemical Nomenclature
Chemical Nomenclature: Provides us with a systematic way of naming and
identifying compounds.
Binary Ionic Compounds

Compounds formed from ONE metal ion and ONE non metal ion
Rule for Naming:
1. Write the full name of the metal ion
2. Write the non metal with the suffix ‘ide’
Example:
NaCl
LiF
sodium chloride
lithium fluoride
Rule for Chemical Formula:
Given the chemical name, for example, Calcium Chloride, we wish to be able to
determine the chemical formula.
NOTE: The charge on the entire molecule must be ZERO
1. Write the number of valence electrons about each atom
2. Find a common number between the atoms
3. Determine the number of atoms required to obtain that common number
or ensure the overall charge is zero.
Calcium Chloride
2+
1-
Ca
Cl
The common number is 2
1 Calcium will give a charge of +2 and 2 chlorine will give a charge of -2 to
balance
Chemical Formula – CaCl2
Ratio of Calcium : Chloride = 1 : 2
Example: Find the chemical formula for magnesium oxide
Multivalent Atoms:
Some atoms exist that have more than one valence, which means that they can
form more than one kind of ion. These are usually in the transition metals.
For example: Fe can create an Fe3+ or an Fe2+ meaning that it transfer 3
electrons in some cases and 2 electrons in other.
In order to differentiate between the two possible valences when we are stating
the chemical name of the compound we place a roman numeral in brackets
beside the atom.
Example:
Iron (II) Oxide  means this compound contains Fe2+
Common Multivalent Metal Ions
Metal
Iron
Copper
Tin
Lead
Cobalt
Ion
Fe2+, Fe3+
Cu+, Cu2+
Sn2+, Sn4+
Pb2+, Pb4+
Co2+, Co3+
IUPAC Name
Iron (II), Iron (III)
Copper (I), Copper (II)
Tin (II), Tin (IV)
Lead (II), Lead (IV)
Cobalt (II), Cobalt (III)
Find the chemical formula for Copper (II) Oxide and Copper (I) Oxide
State the chemical name for SnO2 and PbS
Homework: p. 93 #6a-k, 7a-g, 8a-f, 9, 10
Compounds with Polyatomic Ions
Tertiary Compounds – a compound containing three different elements, usually
a metal ion and a polyatomic ion (covalently bonded group of atoms with an
overall charge).
Oxyanions – polyatomic ions that include oxygen
Common Polyatomic Ions
Name
Formula
Acetate
Bromate
Carbonate
Chlorate
Chromate
Cyanide
Hydroxide
Iodate
Manganate
Nitrate
Phosphate
Sulphate
Thiosulfate
Ammonium
C2H3O2BrO3CO32ClO3CrO42CNOHIO3MnO3NO3PO43SO42S2O32NH4+
Rules for Naming Polyatomic Ions:
Adding or Subtracting Oxygen atoms:
Note there are four polyatomic ions formed from chlorine and oxygen
ClO- - hypochlorite ion
ClO2- - chlorite ion
ClO3- - chlorate ion
ClO4- - perchlorate ion




‘ate’ ending is the base number of oxygen in the polyatomic ion
‘ite’ has one less oxygen than ‘ate’
‘hypo’ – ‘ite’ has two less oxygen than ‘ate’
‘per’ – ‘ate’ has one more oxygen than ‘ate’
Adding Hydrogen atoms:
If hydrogen is every placed in front of the polyatomic ion simply place hydrogen
in front of the name of the polyatomic ion
Examples: Name the following chemical compounds
HSO3-
Ca(ClO4)2
Determine the chemical formulas for the following compounds
Copper (II) Nitrate
Lead (IV) Sulfate
Hydrates:
Hydrates – a compound that contains water as part of its ionic crystal structure
OR
-
a compound that decomposes to an ionic compound and water vapour
when heated
Because water is a polar molecule it has a slight charge on its ends. This causes
water to become attached to some ions.
When water is attached to the compound we say it is hydrated. We can use heat
to remove the water and make the compound anhydrous.
Example:
For hydrated copper (II) sulphate four water molecules surround the copper ion
and one water molecule attaches to the sulphate ion.
Copper (II) sulphate pentahydrate
CuSO4 5H20
Homework: p 96 # 15, 16, 17a-m, 19, 20
Naming Molecular Compounds
There is no fixed ratio when two non metals bond to form a molecular compound,
as a result we use a slightly different system for naming these elements.
Rules for Naming Molecular Compounds:
1. Use the Greek prefixes to indicate the number of one type of atom in the
compound
2. The last atom has a suffix ‘ide’ placed at the end
3. If there is only one atom of the first element we omit the ‘mono’ prefix
Prefixes used when naming Binary Molecular Compounds
Subscript in Chemical Formula
1
2
3
4
5
6
7
8
9
10
Prefix in chemical name
mono
di
tri
tetra
penta
hexa
hepta
octa
nona
deca
Examples: Name the following binary compounds
NO
Nitrogen Oxide
Homework: p. 98 #22a-m, 23
N2O
Dinitrogen Monoxide
NO2
Nitrogen Dioxide
Naming Acids and Bases

The compound is going to be considered an acid when it contains
hydrogen and is found in solution or in aqueous form.
For example:
HCl(g) the subscript (g) tells us that this compound is in it’s gas state
Hydrogen chloride
HCl(aq) the subscript (aq) tells us that this compound is in solution meaning it is
an acid.
Hydrochloric acid
Condition for binary acid
1. Must contain two elements
2. One of the elements must be hydrogen
3. The compound must be in solution (aq).
Rules for Naming a binary acid:
1.
2.
3.
4.
Use ‘hydro’ as the prefix
The other elements name as the stem
‘ic’ as the suffix
‘acid’ at the end
Example:
HF(aq) – hydrofluoric acid
HBr(aq) – hydrobromic acid
Compounds containing Oxyanions in solutions (OXYACID):
We are considering acids formed from the combination of hydrogen with an
oxyanion.
Rules for Naming Acids containing oxyanions
Name of
oxyanion
Per – ate
- ate
- ite
Example
Formula
Persulfate
Sulphate
Sulfite
SO52SO42SO32-
Hypo – ite
Hyposulfite
SO22-
REMEMBER: -ate goes with –ic
Name of
Acid
Per – ic acid
-ic acid
-ous acid
Hypo – ous
acid
and –ite goes with –ous
Example
Persulfuric acid
Sulphuric acid
Sulfurous acid
Hyposulphurous
acid
Example: Determine the chemical formula for the following
Nitrous acid
perphosphic acid
+1
-1
H
NO2
+1
-3
H
HNO2(aq)
PO5
H3PO5(aq)
Naming Bases:

All solutions containing hydroxide ions (OH-) are bases

We are only considering bases made of a metal cation and a hydroxide
anion
Rule for Naming bases containing a hydroxide anion:
1. Put the name of the metal
2. hydroxide at the end
Example:
NaOH(aq) – sodium hydroxide
Homework:
p. 101 #24b,d,f,h,i,k, 25, 26
Ba(OH)2(aq) – barium hydroxide