Ionic Compounds and
Naming
Chapter 4.10,4.11 and 5
When we begin combining elements we
make compounds.
 Two types

◦ Non-metal and metal
◦ Non-metal and non-metal
Each type has unique physical and
chemical properties
 Look at non-metal and metal in detail now
and non-metal and non-metal later

Combining Elements

A metal and a non-metal combination
make an ionic compound
◦ Each element or polyatomic group is an ion
◦ What makes an ion?
 An ion is a charged particle (positive or negative)
 Difference between protons and electrons in an
element
◦ Ca vs Ca+2 (Ca+2 has 2 less electrons than Ca)
Ionic compounds
 The number of valence electrons determines the
type of ion formed
◦ Trying to reach noble gas state
 Lose or gain electrons to reach magic number 8
◦ Valence electrons are known by group number
 Main group elements only
 These atoms follow a pattern down the column
Valence electrons vs charge
How many valence electrons do the
following elements have?
 What would their charge be?

◦K
◦P
Mg
O
Al
Br
C
Ar
◦ Do you see any pattern to the charges?
 Metals make positive ions (cations)
 Non-metals make negative electrons (anions)
Practice
First determine the charge on the cation
and the anion.
 Then adjust the number of cations and
anions you need to make the compound
neutral.
 All ionic compounds are overall neutral;
that is when you add up all the charges
the sum is zero

Making ionic compounds
NaCl is made with Na+1 and Cl-1
 MgO is made with Mg+2 and O-2
 Na2O is made with 2 Na+1 and O-2
 MgCl2 is made with Mg+2 and 2 Cl-1

Making ionic compounds

Combine K and F to make a neutral compound

Put the following elements together to make
ionic compounds





Be and F
Li and S
Ba and N
K and As
Cs and C
◦
◦
◦
◦
K makes a K+1 ion
F makes a F-1 ion
Need one of each to make the ionic compound neutral
KF
Practice

What about the elements in-between
group II and III?
◦ Called transition metals because they can make
more than one positive charge
◦ On our tables you can tell by the small black
number above the symbol…..
Transition metals
Cu II and S
 W IV and O
 Pd II and N
 Cr III and Si

Practice with transition metals

Some ions are actually a group of
elements combined together
◦ Can not be broken apart
◦ Act as one unit

These are known as polyatomic ions
◦ See handout
Polyatomic Ions
Naming Binary Compounds

We can easily name binary compounds
both ionic and covalent (non-metals)
◦ Non-metals and metals use type I and II
◦ Non-metals and non-metals use type III
Naming Binary Compounds

Type I
◦ Metal bonded to non-metal
◦ Metal always listed and named first
 No changes in the metal name
◦ Metals only make ONE ion (known as simple
metals)
◦ Anion is listed second
 Use the root of the name and add –ide
◦ Hydrogen becomes hydride
◦ Halogens remove –ine and add –ide
◦ Oxide, nitride, sulfide
◦ NaCl is sodium chloride
Naming Binary Ionic Compounds

Type II

Cation is first again and anion is changed the
same as type I
The difference is that we need to designate
the charge of the transition metal with a
Roman Number
USE THE ANION TO DETERMINE THE
CHARGE OF THE CATION!!!



◦ use transition metals
CuO
◦
◦
◦
◦
Oxygen is -2
The compound must be neutral
So the copper (Cu) must be +2
The compound is named copper II oxide

Name the following ionic compounds:

CaF
AlCl3
MgI2

CuBr2
Al2O3
CrCl3

Fe2O3
FeO
FeCl3

The number of atoms has no influence on
the name for type I and II
Practice

Polyatomic ions just use their name

K2SO4 would be potassium sulfate

NH4NO3 would be ammonium nitrate
Co(NO2)2
 (NH4)3N

Polyatomic Ions

Type III
◦ Non-metal to non-metals
NUMBER OF ATOMS IS IMPORTANT FOR
TYPE III
 Use prefixes to determine the number of
atoms in the name
 Same naming scheme as type I

 Use entire name for 1st element
 -ide for 2nd
 Add prefixes for multiple atoms
◦ Note: mono- is never used on 1st element

Prefixes
◦
◦
◦
◦
◦
◦
◦
◦
◦
◦
1 – mono
2 – di
3- tri
4- tetra
5- penta
6- hexa
7- hepta
8- octa
9- nona
10- deca
CCl4 would be carbon tetrachloride
 N2O2 would be dinitrogen dioxide


PCl5
P4O6

N2O5
SF6

CO
NO2
Practice



Acids are a special group of binary
compounds and have their own naming rules.
All acids begin with H and are dissolved in
water
Acids without oxygen
◦ Use root of anion and add –ic and acid
◦ HCl is hydrochloric acid

Acids with oxygen
◦
◦
◦
◦
-ite becomes –ous
-ate becomes –ic
H2SO3 is sulfurous acid
H2SO4 is sulfuric acid
Naming Acids

If the anion ends in –ide
◦ Start with hydro
◦ Use the root of the anion
◦ Add –ic acid to the end

If the anion ends in –ate
◦ NO HYDRO
◦ Use the root or slightly more and add –ic acid

If the anion ends in –ite
◦ NO HYDRO
◦ Use the root or slightly more and add –ous acid
Naming acids

Name these acids

HF

HNO3

H3PO4
Practice

Write the formulas from these names:
Nitric acid
 Potassium sulfide
 Sodium carbonate
 Dinitrogen pentoxide

Reversing the process