UNIT IV
Naming Inorganic Compounds
INORGANIC NOMENCLATURE



nomenclature refers to ‘naming’
The periodic table organizes the elements by
vertical groups (________________) and horizontal
rows (__________________).
The elements are arranged in order of increasing
atomic mass; chemical and physical properties
form patterns that repeat at regular intervals.
IV.1 THE CHEMICAL ELEMENTS
Element symbol: The first letter is always in
upper case and the second letter (if present) is
always lower case.
 3 Major classifications:

Non-Metals
Metals
Metalloids
IV.2 NAMING INORGANIC COMPOUNDS

Ion charges indicate whether atoms of an
element want to lose electrons or gain electrons
in order to have a full valence shell.
METALS: form __________________ions
 Cation: an ion with a positive charge

NON-METALS: form ___________________ ions
 (H is generally an exception)
 Anion: an ion with a negative charge

IV.2 NAMING INORGANIC COMPOUDS

Some other definitions:

MONATOMIC –

DIATOMIC –

TRIATOMIC –

POLYATOMIC –
IV.2 NAMING INORGANIC COMPOUNDS
1. Naming Monatomic Ions:
A. NAMING MONATOMIC METAL IONS
 use the name of the metal and add the word
“ion”.
 ex:

Stock System of naming metal ions:
 If it is a multivalent metal (more than one charge
for the ion), the charge is indicated by roman
numerals in brackets.
 ex:

IV.2 NAMING INORGANIC COMPOUNDS
Ex #1: Write the names of the following ions:
 N3+ = __________________________
 Ni2+ = __________________________
Ex #2: Write the formula of the following ions to
show their charges:
 Uranium (VI) ion
= __________
 Iron (II) ion
= __________
 Nickel (II) ion
= __________
IV.2 NAMING INORGANIC COMPOUNDS
B. NAMING MONATOMIC NON-METAL IONS
 take off the original ending and add an “ide”
ending.

ex:
Ex #3: Write the names of the following ions:
a) Br- = __________________________
b) Cl- = __________________________
c) I- = __________________________
d) O2- = __________________________
IV.2 NAMING INORGANIC COMPOUNDS
2. Naming Polyatomic Ions:




What is a polyatomic ion?
Rules for naming are more complicated (we won’t
learn them). But we will need to KNOW some
common polyatomic ions (names, formula, charge).
** Know table on page 69.
In order to name compounds, we must know the
names and chemical formulae of elements.
 do self-test on page 66
 do question # 1 on page 68
IV.2 NAMING INORGANIC COMPOUNDS
3. How to Write the Formula of an IONIC
COMPOUND When Given the Name:


An ionic compound = a compound made up of
ions.
 the ions have charges but the compound is a
neutral molecule.
 example:
The chemical name of an ionic compound always
gives the positive ion (cation) first and the
negative ion (anion) second.
IV.2 NAMING INORGANIC COMPOUNDS

3 simple rules:
RULE
EXAMPLE
1. Write formula for positive
ion first, then negative ion.
Potassium Iodide
2. Swap & drop the numbers
in front of the charges on the
ions (if no number, use a 1).
3. Tidy it up. Reduce
subscripts if both can be
divided by 2. Omit any
subscript that is a 1.
IV.2 NAMING INORGANIC COMPOUNDS
Ex: Sodium chloride: sodium (Na+), chloride (Cl-)
Ex: Iron (II) sulphate: iron (II) (Fe2+), sulphate (SO42-)
Ex: Tin (IV) oxide: tin (IV) (Sn4+), oxide (O2-)

Questions: p. 71 # 4 (odds)
IV.2 NAMING INORGANIC COMPOUNDS
4. How to Write the Chemical Name of an
IONIC COMPOUND When Given the
Formula:
**Check your periodic table to see if the positive
ion has more than one ion charge.
IV.2 NAMING INORGANIC COMPOUNDS
A) If the first ion has only one possible ion
charge:
 write the names of the ions one after the other
 omit the word “ion”

ex: ZnCl2
IV.2 NAMING INORGANIC COMPOUNDS
B) If the first ion has more than one possible
charge:
 “Deswap and dedrop” the charges (find out the
charge)
 check the known charge on negative ion (double
or triple charges if needed)
 write the charge of the positive ion with roman
numerals
 ex: PbO2

ex: Cu2O
IV.2 NAMING INORGANIC COMPOUNDS
** Note: you must memorize the “common name” of
2 compounds:
H2O = water
 NH3 = ammonia


Questions: p. 72 #5 (odds)
IV.2 NAMING INORGANIC COMPOUNDS
5. Naming Hydrates
 Hydrates are ionic compounds that include
water molecules in their crystal structures.
 naming hydrates is pretty straightforward and
relies on using prefixes to tell how many water
molecules are attached.
 the # of water molecules is shown after a
centered dot
IV.2 NAMING INORGANIC COMPOUNDS

**see table of page 72 for prefixes

ex: MgSO4·7H2O

ex: LiNO3·3H2O

Questions: p. 73 #6 and 7
IV.2 NAMING INORGANIC COMPOUNDS
6. Naming COVALENT COMPOUNDS Using
the Prefix-Naming System
 Binary Compound: a compound made of two
different types of atoms (usually non-metals)
 use the prefix-naming system
 ex:
Tertiary Compound: a compound made of three
different types of atoms.
 ex:

IV.2 NAMING INORGANIC COMPOUNDS
RULES:
 each compound name is made of words, each
with a suitable prefix
 see p. 73:
 first word is the name of element with a
prefix to indicate the # of atoms
 second word is the name of the element with
an “ide” ending and a prefix to indicate the # of
atoms


Exception: if there is only ONE atom of the first
element, don’t use the prefix mono. Ex: CO2 =
IV.2 NAMING INORGANIC COMPOUNDS
Examples:
 P2S3 =

CO =

BrCl3 =

S2Cl2 =

Questions: p. 74 #8, 9 (odds)
IV.2 NAMING INORGANIC COMPOUNDS
7. Some Common Acids
 A compound is called an acid when the chemical
formula starts with ‘H’
 ex: HCl, H2SO4

(see common acids on p. 74 – KNOW THESE)
IV.3 COLOURS OF SOME COMMON
AQUEOUS IONS


some ions have characteristics colours.
helpful in chemistry to be able to recognize
these ions

(see table on p. 75 – KNOW)

Questions: p. 75 #10-13



Practice Questions
Naming - p. 75 # 15 – 65 (odds)
Formulas – p. 76 91 – 125 (odds)