Compounds and
Nomenclature
Bonding & Stability


Atoms want to be stable.
The Octet Rule states that a chemically stable
atom contains 8 valence electrons.
Chemical Bonds


Atoms will gain, lose, or share electrons to obtain 8
valence electrons – this is called a chemical bond
There are 3 types of bonds:
 Metallic
 Ionic
 Covalent / Molecular
Ionic Bonds
Types of Compounds
1. Ionic Compounds:
- involve the transfer of electron(s) between 2
oppositely charged ions (cation and anion)
- metal and a nonmetal or a combination involving a
complex ion
- forms an ionic bond
- exists as an ionic crystal lattice (not individual
molecules)
- known as a formula unit (eg. A formula unit of salt,
not a molecule)
Crystal Lattice
Formula Unit


a chemical formula showing the simplest
whole number ratio of cations to anions in an
ionic compound.
Eg. NaCl – sodium chloride
Types of Compounds (continued)
2. Molecular compounds:
- involve the sharing of electrons between
nonmetals
- forms a covalent bond
- exists as individual molecules
- Eg. Carbon dioxide CO2
water H2O
Covalent Bond/Molecule
Ionic and Covalent Bonds
Properties of Ionic and Molecular Compounds
1. State at room temperature:
- all ionic compounds are solids
- molecular compounds may be a solid, liquid or a
gas
2. Conductivity of solution:
- ionic compounds conduct electricity
(electrolytes)
- molecular compounds do not conduct electricity
(non- electrolytes)
3. Solubility in water:
- ionic compounds are soluble, to varying
degrees (some better than others) and
form colored or colorless solutions.
- molecular compounds may or may not be
soluble (colorless solutions if they
form).
Nomenclature

Chemical nomenclature is the systematic
naming of chemical compounds.

Science 1206 examines the naming of ionic
compounds, molecular compounds and acids.
Compounds can be divided into two basic categories,
those which are true binary compounds (contain only
two types of elements), and those which contain
more than two different types of elements.

Is there a metal or ammonium in the formula?
Is there a metal or ammonium in the formula?
Is there a metal or ammonium in the formula?
Is there a metal or ammonium in the formula?
Is there a metal or ammonium in the formula?
Is there a metal or ammonium in the formula?
Is there a metal or ammonium in the formula?
Ionic compounds
Identify the type of ions:
A. Monoatomic or simple ions
B. Polyatomic or complex ions
C. Multivalent ions
D. Hydrates
Rules for Naming ionic compounds:
A.




Monoatomic or simple ions
Single atoms that have lost or gained one or
more electrons
Form binary ionic compounds (2 simple ions)
Consist of cations and anions
Eg. Sodium + chlorine Na+ Cl-



Cations are written first, anions are second
(name changes to “-ide” for the anion)
The total charge must be zero
Do not write charges in your final answer
Is there a metal or ammonium in the formula?
Is there a metal or ammonium in the formula?
Is there a metal or ammonium in the formula?
Is there a metal or ammonium in the formula?
Is there a metal or ammonium in the formula?
Is there a metal or ammonium in the formula?
Is there a metal or ammonium in the formula?
Rules for formulas:
a. Write the symbols for the ions involved:
eg. Silver and chlorine
Ag+ and Cl-
Rules:
b. Determine the lowest whole number ratio of ions
which will provide an overall net charge of zero
Ag1+ Cl1- becomes AgCl
(silver chloride)
Example: potassium and oxygen
potassium - K+
oxygen O2K2+ O12becomes K2O
potassium oxide
Practice – Writing Formulas
Write formulas for the following compounds:
Lithium bromide
Potassium chloride
Barium chloride
Magnesium nitride
Aluminum Fluoride
Calcium Nitride
Is there a metal or ammonium in the formula?
Is there a metal or ammonium in the formula?
Is there a metal or ammonium in the formula?
Is there a metal or ammonium in the formula?
Is there a metal or ammonium in the formula?
Is there a metal or ammonium in the formula?
Is there a metal or ammonium in the formula?
Naming Ionic Compounds

Cation is named first
Anion is named second
Ending of anion is changed to “ide”

Practice:


NaCl
BaCl2
Al2O3
B. Multivalent ions
- certain transition
metals can form more
than one type of ion,
each with a different
charge.
eg. Cu2+ - copper (II)
Cu+ - copper (I)
Multivalent ions (continued)



The transition metals have various electron
configurations that will make them stable
Use a roman numeral after the cation to
specify its charge (Stock naming system).
Eg. Iron (ii) oxide
FeO
Iron (iii) oxide
Fe2O3
Stock vs. Classical
Formula
 Cu+
 Cu2+
 Fe2+
 Fe3+
Stock Name
copper(I) ion
copper(II) ion
iron(II) ion
iron(III) ion
Classical Name
Cuprous ion
Cupric ion
Ferrous ion
Ferric ion
- the one written on top is the more common
ion
- eg.
Fe3+ - iron (III)
Fe2+ - iron (II)
Practice:
CuSO4
PbO
uranium (vi) oxide
uranium (iv) oxide
C. Polyatomic/Complex Ions

Polyatomic ion: atoms of 2 or more elements
covalently bonded together with an overall
charge
eg.

Nitrate NO3Ammonium NH4+
Complex ions are groups of atoms that are
made stable by sharing electrons and which
then become even more stable by gaining
(usually) or losing electrons.


The total positive charge in the formula must
be equal to the total negative charge.
Rules:




Name the cation, then name the anion
Don’t change the ending of a polyatomic ion!
Balance the charges
If you need more than 1 complex ions, use
brackets for that group
Practice
NaNO3
Al2(SO4)3
Mg(OH)2
NaCH3COO
Is there a metal or ammonium in the formula?
Is there a metal or ammonium in the formula?
Is there a metal or ammonium in the formula?
Is there a metal or ammonium in the formula?
Is there a metal or ammonium in the formula?
Is there a metal or ammonium in the formula?
Is there a metal or ammonium in the formula?
D. Hydrates


Ionic compounds that contain water in their
structure
eg. CuSO4 H2O
Hydrate - Rules




Name the ionic part of
the formula first
Name the water part
second using a prefix
system for the number
of water molecules
Add prefix to “hydrate”
Prefixes:
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
mono
di
tri
tetra
penta
hexa
hepta
octa
nona
deca
Example:
CuSO4 5H2O
Copper (II) sulfate pentahydrate
Review
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
Silver nitrate
Iron(II) phosphate
Chromium(III) oxide
Nickel(II) fluoride
Copper(I) nitrate heptahydrate
Lead(II) carbonate
Iron(II) fluoride
Iron(III) hydroxide
Zinc phosphate dihydrate
Potassium chlorate
Ammonium chromate
12. Copper(II) sulfate
13. Cobalt(II) iodide
14. Cesium phosphate
15. Magnesium acetate
16. Potassium oxide
17. Strontium nitrate
18. Aluminum sulfate
19. Calcium chlorate
20. Rubidium cyanide
21. Tin(IV) oxide
22. Titanium(II) iodide
Ionic Formulas
1.
2.
3.
4.
5.
6.
7.
8.
BaCl2
Pb(NO3)2
TiI3
K2CrO4
CoO
Mg(ClO4)2
CuSO4
Na2SO3
10. FeCl3
11. Ca(CN)2
12. Cu2S
14. Cd(ClO)2
15. SnO2
16. NaHCO3
17. Al(C2H3O2)3
18. Ni3(PO4)2
Molecular Compounds
Chemical Bonding
Is there a metal or ammonium in the formula?
Is there a metal or ammonium in the formula?
Is there a metal or ammonium in the formula?
Is there a metal or ammonium in the formula?
Is there a metal or ammonium in the formula?
Is there a metal or ammonium in the formula?
Is there a metal or ammonium in the formula?
NO!!!!!!!!!
Molecular Compounds



Binary molecular compounds form between 2
non-metals
Covalent bonds: shared electrons
Molecular formula: shows number and kind
of atoms in a molecule
Naming




Use prefixes to specify
number of atoms of each
element in the molecule
Second element ends with
“-ide”
No charges used in formula
The prefix “mono-” should
not be used on the first
element
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
mono
di
tri
tetra
penta
hexa
hepta
octa
nona
deca
Practice

Name the following:




NO
CO2
N4O9
N6O

Write formulas for the
following:




Boron trifluoride
Sulfur hexafluoride
Nitrogen monoxide
Phosphorous
pentachloride
Acids
ACIDS






HCl
H2SO4
HNO3
HC2H3O2
H3PO4
H2CO3
Hydrochloric Acid
Sulfuric Acid
Nitric Acid
Acetic Acid
Phosphoric Acid
Carbonic Acid
Acids have 2 criteria:
1.
They must contain hydrogen (H+)
2.
They must be dissolved in water
(aqueous); the formula will always
contain the subscript aq.
Naming Acids
Hydrogen is always the positive ion for an acid

Ending
1. -ide
Example
HCl
2. –ite
Acid Name
begins with hydro,
ends with -ic and acid
ends with –ous and acid
3. –ate
ends with –ic and acid
H2SO4
H2SO3