Transcript Bonding Nomenclature Notes

Chapters 4 & 12
Nomenclature
and
Chemical Bonding
1
Ionic Compounds



Octet Rule -atoms will gain, lose, or share
electrons to achieve a noble gas
configuration.
Ionic compound -a compound composed
entirely of ions
 formed by the gaining and losing of
valence electrons
Ionic Bonding - a positively charged ion
is attracted to a negatively charge ion.
1)
2)
3)
Cation -positively charged ion
Anion -negatively charged ion
Typically between a metal and a nonmetal.
2
Properties of Ionic Compounds:

overall neutral
2) high melting points
3) generally brittle solids
4) dissolve in water to form electrolytes
Types of Ions:

Monatomic Cations – positively charged
ions formed from 1 atom
Li+
Mg2+

To name a cation add the word ion after
the element’s name.
Lithium ion
Magnesium ion
1)
3



Some elements can form more than
one ionic charge (Transitional Metals)
 Iron: Fe2+ and Fe3+
 Iron (II) ion
Iron(III) ion
Monatomic Anions – negatively
charged ions formed from 1 atom
FO2Naming a monatomic anion, replace
the ending of the name with –ide.
flouride
oxide
4
 Polyatomic Ions -ions that consist of more
than 1 atom
 C2H3O2- Acetate
 NH4+
Ammonium
 Rules for writing formulas for ionic
compounds:
1) Write the symbol for the cation first.
2) Write the symbol for the anion second.
3) Add subscripts so the charges equal
zero when added.
5
 Rules for naming ionic compounds:
1) Write the name of the cation unchanged
first.
2) Write the root of the anion with the –ide
ending.
 Binary Compound - ionic compound
composed of two atoms.
 Formula unit-the smallest
representative unit
1) Mg2+ + Cl1- 
MgCl2
2) Fe2+ +
O2- 
Fe2O2  FeO
3) Al3+ +
S2- 
Al2S3
6

Hydrates - ionic compounds that
absorb water into their solid
structures: CuSO4 • 5H2O

Polyatomic Ionic (Ternary)
Compounds- contains atoms of
three different elements.
1) K1+
+
NO31-
1) Mg2+ + OH11) Cu2+ +


KNO3
Mg(OH)2
PO43-  Cu3(PO4)2
7
Prefix
monoditritetrapentahexaheptaoctananodeca-
Number
1
2
3
4
5
6
7
8
9
10
8
Writing and Naming Covalent Compounds

Covalent Bond – formed by the sharing of
electrons

Molecule -the smallest representative unit

Molecular Compound -compounds composed
of molecules

Molecular Formula -shows the kind and
numbers of atoms present in a molecule of an
atom

Properties Of Covalent Compounds
1)
2)
3)
4)
made of two nonmetals
low melting and boiling points
solid, liquid, or gas at room temp.
do not dissociate in water
9
 Naming Covalent Compounds
CO CO2
CO32C2O42 Rules for naming covalent compounds:
1) Write the less electronegative
element first.
2) Write the root of the more
electronegative element with the -ide
ending second.
3) Add prefixes to both indicating the
number of atoms of each element
10
Exceptions:
1. Do not use mono-with the first
element in the compound
2. Prefixes are sometimes shortened.
CO
Carbon Monoxide
3. Chemist use common names for
some compounds other than the
formal names.
NH3
Nitrogen Trihydride
11
Electronegativity -the attraction to electrons
involved in a chemical bond
Two Types of Covalent Bonds
1. Polar Covalent Bond -one atom in a molecule
is significantly more electronegative
-This causes a slight positive and negative
charge on a molecule.
2. Nonpolar Covalent Bond -electrons are shared
equally
Electronegativity Differences
Bond Type
 0.3
non-polar
0.4 - 1.9
polar
 2.0
ionic 12

Structural Formulas -specifies which
atoms are bonded to each other in a
molecule
F2
NH3

Single Covalent Bond -two atoms share
1 pair of electrons
Double Covalent Bond -two atoms share
2 pair of electrons
Triple Covalent Bond -two atoms share 3
pair of electrons


13

Acids -a molecular substance that dissolves in
water to produce a hydrogen ion



acts like an ionic compounds because they break down into cations
and anions in water
produces a characteristic anion for which it is named
If the anion ends with… -ide such as chloride,
fluoride

add the prefix
hydro- and change the ending to –ic and add the
word acid

If the anion ends with… -ate such as phosphate, sulfate


change the ending to –ic and add the word acid.
If the anion ends with… -ite such as sulfite, phosphite

change the ending to –ous and add the word acid
14