

IUPAC (The International Union of Pure and
Applied Chemistry) is the organization
responsible for the naming of chemical
compounds.
Using IUPAC guidelines ensures the use of a
consistent, practical way of naming that
allows all scientists to communicate clearly
and precisely.

Ionic compounds form when electrons
transfer from one atom to another.
 Binary ionic compounds consist of a cation and an
anion
 NaCl
 Na has 1 valence electron, and Cl has 7 valence electrons.
When they combine the 1 Na electron transfers to the Cl
atom. The result, both have full outer energy levels.
 the positive sodium ions are attracted to the negative
chloride ions.
 This is called ionic bonding, when bonds are formed
between ions of metals (+) and non-metals (-).
Illustrating the bonding of Sodium
and Chlorine
+
Na
-
Cl
Sodium is
soft and very
reactive metal
11P
12N
Sodium
Na = 2,8,1
It has only 1
electron in its
outside shell
Chlorine is a
highly
poisonous
green gas.
17P
18N
Chlorine
= 2,8,7
It has 7
electrons in
the outside
shell and is
not stable.
Na
11P
17P
12N
18N
Cl
Na
11P
17P
12N
18N
Cl
Na
11P
17P
12N
18N
Cl
11P
17P
12N
18N
Na +
Cl-
2,8
2,8,8
11P
12N
17P
Strong forces of
attraction exist
between Na+ and
Cl- and hold the
bond together
18N
Na+
Cl-
2,8
2,8,8
The Octet Rule:
The Octet rule is
simply a rule
which helps us to
understand
bonding
Atoms bond
together so
that each
atom attains
an electron
arrangement
of 8 electrons
in its
outermost
shell.



Na lost 1 electron
Na changed from
electron
configuration of
2,8,1 to 2,8
Na changed from a
neutral Na atom to
a positively
charged Na ion
(Na+)
Cl gained 1
electron
 Cl changed from
electron
configuration of
2,8,7 to 2,8,8
 Cl changed from a
neutral Cl atom to a
negatively charged
Cl ion (Cl-)

1. Name the metal first by using the element’s
name.
2. Than name the non-metal using the suffix
“ide”.
 NaCl (Na+ and Cl-), sodium chloride.
 BaF (Ba2+ and F-), barium fluoride.
1. Identify the ions and their charges.
 Aluminum ion: Al3+
 Chloride ion: Cl-
2. Determine the total charges needed to balance. All
ionic compounds must have an equal number of
positive and negative charge.
 total charge of anions = total charge of cations
 Al3+ : 3
 Cl- : 1+1+1=3
3. Note the ratio of cations to anions.
 1 to 3
4. Use subscripts to write the formula, if needed.
Always use the smallest whole number ratio.
 AlCl3
Write the formulas for the following ionic
compounds.
a) magnesium chloride
b) sodium sulfide
c) calcium phosphide
a) magnesium chloride




magnesium ion: Mg2+ chloride ion: ClMg2+:2 Cl-: 1+1=2
1:2
MgCl2
b) sodium sulfide




sodium ion: Na+ sulfide ion: S2Na+: 1+1=2 S2-: 2
2:1
Na2S
c) calcium phosphide




calcium ion: Ca2+
Ca 2+: 2+2+2=6
3:2
Ca3P2
phosphide ion: P3P3-: 3+3=6
Elements with more than one ion are called
multivalent elements.
 Iron has two stable ions: Fe2+ and Fe3+
 Ionic compounds containing multivalent elements
must have Roman numeral in their names to indicate
which ion is forming that compound.
 FeCl3 -> iron (III) chloride
1. Identify the ions that form the compound.
2. Use the charge of the known ion and the rule
that the total positive and negative charge in
the formula unit must equal to determine the
unknown charge of the multivalent element.
3.Write the name of the compound. Remember
the Roman numeral must be in brackets.
Write the name of the following compounds:
a) PbO2(s)
b) Ni2S3(s)
c) CuF2(s)
Write the name of the following compounds:
a) PbO2(s)
 lead (IV) oxide
b) Ni2S3(s)
 nickel (III) sulfide
c) CuF2(s)
 copper (II) fluoride
Polyatomic Ions are ions made up of
several non-metallic atoms joined
together.
 hydroxide ion (OH-), when in a compound such
as NaOH, Na has a charge of 1+, O and H
together form the polyatomic hydroxide ion,
with a charge of 1-.
Two common suffixes used in naming
polyatomic ions are "-ate" and "-ite”
 "-ate" means more atoms are a part of the ion
 "-ite" means less atoms are a part of the ion
 The suffixes do not tell you how many atoms are
in the formula.
 "-ate" and "-ite" are used when similar ions exist.
 sulfate (SO42-) and sulfite (SO32-), sulfate has one
more oxygen atom than sulfite.
If more than 2 variation exist, then other naming strategies are
used.
•
•
•
More than two types of atoms indicates
there is a polyatomic ion
Look at the formula, name the cation,
followed by the anion.
You do not need to change the ending of
the polyatomic ion.

Au(NO3)3(s)

(NH4)3PO4(s)

K2Cr2O7(s)
gold nitrate

Au(NO3)3(s)

(NH4)3PO4(s) ammonium phosphate

K2Cr2O7(s)
potassium dichromate
Rules are similar to writing ionic compounds,
except:
•
•
When more than one polyatomic ion is required you
must use brackets to indicate multiples of the group
of atoms
i.e. Ca(OH)2(s)
The formula unit for an ionic compound always
consists of positive and negative ions in the smallest
whole-number ratio that results in a neutral unit.
i.e. NH4+ and HCO3- results in NH4HCO3(s)
Rules for writing:

Identify the ions and their charges.
 iron (III) sulfate
 iron (III): Fe3+
 sulfate: SO42-

Determine the total charges needed to balance
 Fe3+ : 3 + 3 = 6
 SO42- : 2 +2 + 2 = 6

Note the ratio of cations to anions
 Ratio 2:3

Use brackets and subscripts if needed to write the
formula. This is not required when it is a 1:1 ratio.
 Fe2(SO4)3
Write the formulas of the following ionic
compounds:
 barium hydroxide
 iron(III) carbonate
 copper(I) permaganate
 barium hydroxide




Ba2+
2
Ratio 1:2
Ba(OH)2
OH1 + 1 =2
 iron(III) carbonate




Fe3+
3
Ratio 1:1
FeCO2
CO233
 copper(I) permaganate
 Cu1+
 1
 Ratio 1:1
 CuMnO4
MnO411
These are elements that form molecules from
only one type of atom. There are 3 kinds of
molecular elements.
 Monatomic - elements that can exist on there own. Ex.
Carbon, noble gasses, and all metals.
 Diatomic - elements from the in pairs of itself. Ex. H2,
O2, N2 , F2 , Cl2 , Br2 , I2 (seven that make a 7)
*memorize*
 Polyatomic - molecules that can exist with more than
one pair of itself. Eg. O3, P4, S8




Bonding between two non metals
Name the first non-metal element.
Name the 2nd element with "ide" at the end.
Add Greek prefixes indicating the number of atoms
 N2O -> dinitrogen monoxide
 PBr3 ->phosphorous tribromide
 Note that the prefix "mono" is not usually used when an
element is single
Greek Prefixes
1-mono
2-di
3-tri
4-tetra
5-penta
6-hexa
7-hepta
8-octa
9-nona
10-deca
Write the name or formula of these molecular
compounds:




CO2(g)
PCl3(g)
oxygen difluoride
dinitrogen tetrasulfide
 CO2(g)
 carbon dioxide
 PCl3(g)
 phosphorus trichloride
 oxygen difluoride
 OF2
 dinitrogen tetrasulfide
 N2S4
Homework: Read Science 10 p. 40-50 Check
and Reflect # 1-12, due the next day.