Ch.5 (Types of compound )
Section 1(Ionic Compound)
Gr.10 /Chemistry/LC3
Nagham Hussam
Chemistry Teacher
Ionic compounds
Ionic compounds are:
1. Made up of
oppositely charged
ions held together
strongly in wellorganized units.
2. Hard solids at room
temperature and are
difficult to melt.
Look at the structure
of magnesium oxide.

The smallest part of compounds
Molecule: the smallest unit of the
compound in a covalent compound.
 Formula unit The simplest ratio of ions
in a compound.

Binary Ionic Compounds
You will learn how to name and write
formulas for ionic compounds.
 Binary compound: a compound that
contains only two elements.
 Ex: Sodium chloride (NaCl), potassium
iodide (KI) and (CaF2) calcium florid
(contain more than one ion of each
element)

Predicting Charge on Ions
Predicting Charge on Ions
Oxidation numbers for elements in Groups
3 through 12, the transition elements, cannot
be predicted by group number.
 Aluminum is in Group 13, so it loses its three
outer electrons to become an Al3+ ion; oxygen
is in Group 16 and has six valence electrons, so
it gains two electrons to become an O2– ion.

How to name a binary ionic
compound
To name a binary ionic compound, first
write the name of the positively charged
ion, usually a metal, and then add the
name of the nonmetal or negatively
charged ion, whose name has been
modified to end in -ide.
 Magnesium combines with oxygen to
form a compound called magnesium
oxide (MgO).

How to write the formula
Sodium chloride contains sodium ions that have
a 1+ charge and chloride ions that have a 1–
charge.
 the sum of the charges in an ionic compound
must always equal zero.

Learning Check
Write the correct formula for the compounds
containing the following ions:
A. Na+, S21) NaS
2) Na2S
3) NaS2
B. Al3+, Cl1) AlCl3
2) AlCl
3) Al3Cl
C. Mg2+, N31) MgN
2) Mg2N3
3) Mg3N2
Solution
A. Na+, S22) Na2S
B. Al3+, Cl1) AlCl3
C. Mg2+, N33) Mg3N2
Naming Binary Ionic Compounds
Contain 2 different elements
Name the metal first, then the nonmetal as ide.
NaCl
ZnI2
Al2O3
Examples:
sodium chloride
zinc iodide
aluminum oxide
Learning Check
Complete the names of the following binary
compounds:
Na3N
sodium
________________
KBr
potassium ________________
Al2O3
aluminum ________________
MgS
_________________________
Solution
Complete the names of the following binary
compounds:
Na3N
sodium nitride
KBr
potassium bromide
Al2O3
aluminum oxide
MgS
magnesium sulfide
Learning Check
A. The formula for the ionic compound of
Na+ and O2- is
1) NaO
2) Na2O
3) NaO2
B. The formula of a compound of aluminum and
chlorine is
1) Al3Cl
2) AlCl2
3) AlCl3
C. The formula of Fe3+ and O2- is
1) Fe3O2
2) FeO3
3) Fe2O3
Solution
A. The formula for the ionic compound of
Na+ and O2- is
2) Na2O
B. The formula of a compound of aluminum
and chlorine is
3) AlCl3
C. The formula of Fe3+ and O2- is
3) Fe2O3
Transition Metals
Many form 2 or more positive ions
1+
2+
Ag+
Cd2+
silver
ion
cadmium
copper(I) ion
iron(II)
ion
copper (II) ion iron(III) ion
Zn2+
zinc ion
1+ or 2+
Cu+,Cu2+
2+ or 3+
Fe2+, Fe3+
Names of Variable Ions
Use a roman number after the name of a
metal that forms two or more ions
Transition metals and
the metals in groups 4A and 5A
FeCl3
(Fe3+)
iron (III) chloride
CuCl
SnF4
PbCl2
Fe2S3
(Cu+ )
(Sn4+)
(Pb2+)
(Fe3+)
copper (I) chloride
tin (IV) fluoride
lead (II) chloride
iron (III) sulfide
Learning Check
Complete the names of the following binary
compounds with variable metal ions:
FeBr2
iron (_____) bromide
Cu2O
copper (_____) oxide
SnCl4
___(_____ ) ______________
Fe2O3
________________________
CuS
________________________
Solution
Complete the names of the following binary
compounds with variable metal ions:
FeBr2
iron ( II ) bromide
Cu2O
copper ( I ) oxide
SnCl4
tin (IV) chloride
Fe2O3
iron (III) oxide
CuS
copper (II) sulfide
Learning Check
Name the following compounds:
A. CaO
1) calcium oxide
2) calcium(I)
oxide
3) calcium (II) oxide
B.
SnCl4
1) tin tetrachloride
3) tin(IV) chloride
C. Co2O3
1) cobalt oxide
3) cobalt trioxide
2) tin(II) chloride
2) cobalt (III) oxide
Solution
Name the following compounds:
A. CaO
1) calcium oxide
B.
SnCl4
C.
Co2O3
3) tin(IV) chloride
2) cobalt (III) oxide
Compounds Containing Polyatomic
Ions

Polyatomic ion: An ion that has two or
more different elements.
Compounds Containing Polyatomic Ions
Compounds Containing
Polyatomic Ions
Ionic compounds may contain:
1. positive metal ions bonded to negative polyatomic ions,
such as in NaOH .
2. negative nonmetal ions bonded to positive polyatomic
ions, such as in NH4I .
3. or positive polyatomic ions bonded to negative polyatomic
ions, such as in NH4NO3.
How to write formula of Compounds
Containing Polyatomic Ions
Remember that the sum of the positive
and negative charges must equal zero.
 Write a subscript outside the
parentheses to show the number of
polyatomic ions in the compound.
 The formula for the compound that
contains one magnesium ion and two
nitrate ions is Mg (NO3)2.

How to name a compound
containing a polyatomic ion
To name a compound containing a
polyatomic ion, follow the same rules as
used in naming binary compounds.
 The name of the compound composed
of calcium and the carbonate ion is
calcium carbonate.
 To form a neutral compound, one Ca2+
ion must combine with one CO32– ion to
give the formula CaCO3.

Hydrates
Hydrate: A compound in which there is
a specific ratio of water to ionic
compound. For example CaSO4 • 2H2O
is calcium sulfate dihydrate.
 Hygroscopic: compounds can easily
become hydrates by absorbing water
molecules from water vapor in the air.
Example is Sodium Carbonate (Na2CO3).

Hydrates
Deliquescent: Substances those are so
hygroscopic that they take up enough water from
the air to dissolve completely and form a liquid
solution.
Hydrates
The dot in the formula represents a
ratio of compound formula units to
water molecules.
 For example, CaSO4 • 2H20 is the
formula for a hydrate of calcium sulfate
that contains two molecules of water
for each formula unit of calcium
sulfate.

How To name hydrates
To name hydrates, follow the regular
name for the compound with the word
hydrate, to which a prefix has been added
to indicate the number of water
molecules present.
 The name of the compound with the
formula CaSO4 • 2H2O is calcium
sulfate dihydrate.

Anhydrous compound
Heating hydrates can drive off the water.
 This results in the formation of an anhydrous
compound—one in which all of the water has
been removed.
 In some cases, an anhydrous compound may
have different color from that of its hydrate. For
example: CuSO4.5H2O is (blue) while
anhydrous of CuSO4 is (white)

Good luck