Transcript PowerPoint Presentation - Chemical Names and Formulas

Chemical Names and
Formulas
Overview
•Metals and Non-Metals
•Ions and Ionic Charges
•Types of Compounds
•Systematic Names
-Writing Names and Formulas
3-
PO4
phosphate ion
Nomenclature
HC2H3O2
Acetic Acid
C2H3O2acetate ion
Metals and Nonmetals
Stairway Of Division on Periodic Table
 C, P, Se, I, Rn and to the right are nonmetals
 B, Si, As, Ge, Sb, Te, Po, At are semimetals
 All others are metals

Ions
 Cations
 Anions
Positively
Charged
Atoms
+
 i.e.
Na
Negatively
Charged
Atoms
 i.e.
Cl
Properties of Ionic Compounds
Forming NaCl from Na and Cl2

A metal atom can
transfer an electron to
a nonmetal.

The resulting cation
and anion are attracted
to each other by
electrostatic
forces.
IONIC CHARGES

Group I ->
1+

Group II ->
2+

Group III ->
3+

Group IV ->
4+
IONIC CHARGES

Group V ->
3-

Group VI ->
2-

Group VII ->
1-

Group VIII ->
Noble Gases
Predicting Charges on Monatomic Ions
KNOW THESE !!!!
+1 +2
+3 +4 -3 -2 -1
Cd+2
0
Forms of Chemical Bonds
There are 3 forms bonding
atoms:
 Ionic—complete transfer of 1
or more electrons

Most bonds are
somewhere in
between ionic
and covalent.

Covalent—sharing of one or
more valence electrons

_________ – holds atoms of
a metal together
TYPES OF COMPOUNDS
 Ionic
Compounds
• usually
formed from a metal and
non-metal.
• these elements are not attached
to one another.
Formulas of Ionic Compounds
Formulas of ionic compounds are determined from
the charges on the ions
atoms
Na  +

ions

F : 

sodium + fluorine
Charge balance:
 _
Na+
: F :  NaF

sodium fluoride
1+
1-
formula
= 0
TYPES OF
COMPOUNDS
 Ionic
Compounds con’t
• Examples
NaCl
CaBr2
KI
CHEMICAL FORMULAS
 Definition
• shows the kind and numbers of
atoms in the smallest
representative unit of the
substance.
 i. e.
NaCl
IONIC COMPOUNDS
A
formula unit is the lowest
whole number ratio of ions in an
ionic compound.
 i.e.
 There
Na2Cl2
-> NaCl
is no such thing as a
molecule of NaCl!!!!!!!!!
NAMING
COMPOUNDS
 Your
ability to name compounds
and write formula’s hinges on
your ability to recognize whether
a compound is Ionic or
Molecular.
BINARY IONIC
COMPOUNDS
 Binary
means 2 elements
 Ionic means a metal and a nonmetal (or cation and anion)
 Writing Formulas
• charges must balance so
compound charge is neutral.
COMPOUNDS
FORMED
FROM IONS
CATION +
ANION --->
COMPOUND
Na+ + Cl- --> NaCl
A neutral compound
requires
equal number of +
and - charges.
BINARY IONIC
COMPOUNDS
 Writing
Formulas from Names
• 1st word = CATION
• 2nd word = ANION name
with ide ending.
BINARY IONIC
COMPOUNDS
 Potassium
Chloride
 Aluminum
Oxide
• notice ending
of name is ide!
+
K Cl
-> KCl
Al23+O32- ->
Al2O3
Polyatomic Ions
 Definition
•tightly bound groups of
atoms that behave as a unit
and carry a charge.
 Example
2SO3 , NO2 , ClO2
TERTIARY IONIC
COMPOUNDS
Tertiary
means 3 different
elements
Usually contain Poly-atomic
Ions
Ionic means cation and anion
TERTIARY IONIC
COMPOUNDS:Writing
Formulas
 Ca2+CO32-
->
CaCO3
Calcium
Carbonate
TERTIARY IONIC
COMPOUNDS: Naming
Calcium
Nitrate
Ca(NO3)2
Transition Metals: Metals that form more
than One Cation
The name of metals with two or more positive ions
(cations) use a Roman numeral to identify ionic charge.
Lead
Pb2+
lead(II)
Pb4+
lead(IV)
Copyright © 2005 by Pearson Education, Inc.
Publishing as Benjamin Cummings
24
Naming with Transition
Metals
 First
word = CATION
 Second word = ANION
 Pay attention to subscript on anion
to determine oxidation state
(Roman Numeral in parentheses)
of Transition Metals
Common Transition Metals with
more than one Oxidation State
Copper
 Tin
 Lead
 Iron
 Cobalt
 Manganese
 Mercury
 Nickel

Naming Ionic Compounds with
Variable Charge Metals
Copyright © 2005 by Pearson Education, Inc.
Publishing as Benjamin Cummings
27
Naming FeCl2
To name FeCl2
1. Determine the charge of the cation using the charge
of the anion (Cl-).
Fe ion + 2 Cl- = Fe ion + 2- = 0
Fe ion = 2+
2. Name the cation by the element name and add a
Roman numeral in parenthesis to show its charge.
Fe2+ = iron(II)
3. Write the anion with an ide ending.
FeCl2 = iron(II) chloride
29
Naming Transition
Metals
Copper
Oxide
(I)
Cu2O
Writing Formulas with
Transition Metals
Iron (III)
FeCl3
Chloride
Iron (II)
FeCl2
Chloride
Learning Check
Select the correct name for each.
A. Fe2S3
1) iron sulfide
2) iron(II) sulfide
3) iron(III) sulfide
B. CuO
1) copper oxide
2) copper(I) oxide
3) copper(II) oxide
32
Solution
Select the correct name for each.
A. Fe2S3
3) iron (III) sulfide
Fe3+ S2-
B. CuO
3) copper (II) oxide
Cu2+ O2-
33
TYPES OF
COMPOUNDS
 Molecular
Compounds- Formed
by Covalent Bonds
• composed of molecules in
which elements share
electrons.
• usually composed of 2
nonmetals.
• these elements are attached
MOLECULAR
FORMULA
 Definition
• shows the numbers and
kinds of atoms present in a
molecule of a compound.
 i. e.
CO
TYPES OF
COMPOUNDS
 Molecular
Compounds con’t
•Examples
CS2
SiO2
BF3
BINARY MOLECULAR
COMPOUNDS
Binary
means 2 elements
Molecular means 2 nonmetals
NO ionic charges are
present
Naming Binary
Molecular Compounds
 Prefixes
are used to show how
many atoms are present in each
molecule.
 Mono (1), di (2), tri (3), tetra
(4), penta (5), hexa (6), hepta
(7), octa (8), nona (9), deca (10)
Writing Binary
Molecular Compounds
Carbon
CO2
Dioxide
•no mono
prefix is used
on first element
• Di means 2
oxygens!!
Naming Binary
Molecular Compounds
2
ways it’s done!
• (prefix + element name)
i.e. N2O
dinitrogen monoxide
Naming Binary
Molecular Compounds
• (prefix + element root + ide)
i.e. PCl3
Phosphorous
Trichloride
 All binary compounds end in
ide!!!