Unit 10
DETERMINING FORMULAS
AND NOMENCLATURE
CHEMICAL FORMULAS

Clearest and simplest method of
designating compounds
Shows number of atoms using
subscripts

Shows the kind of elements in the
compound

EXAMPLE OF CHEMICAL
FORMULA
VITAMIN A
C20H30O
SALTS

COMPOUNDS THAT
BEGIN WITH A METAL or
NH4
SALTS

BINARY SALTS
– Contain only two elements: a
metal and a nonmetal
–To name a binary salt:
Name the metal
Drop ending of nonmetal
and add "ide"
PRACTICE NAMING
BINARY SALTS
1.
2.
3.
4.
5.
NaCl
CaF2
K2O
lithium nitride
aluminum iodide
TERNARY SALTS

Contain three or more elements metal and polyatomic ion

To name a ternary salt:
–Name metal
–Name polyatomic ion
PRACTICING WRITING
TERNARY SALTS
1.
2.
3.
4.
5.
K3PO4
CaCO3
Al(NO3)3
barium hydroxide
cesium chromate
Multiple Ox# SALTS


The metals may have more than
one oxidation number
To name the salt:
–Name the metal
–Put Roman numeral after the
metal to indicate oxidation state
being used
–Same ending as other salts
PRACTICING SPECIAL
SALTS
1.
2.
3.
4.
5.
FeCl2
6. nickel II iodide
FeCl3
7. chromium II phosphate
Cu(NO2)2
PbSO4
cobalt III hydroxide
COVALENT (nonmetal)
COMPOUNDS

BEGINS WITH NONMETAL
OTHER THAN H
NAMING COVALENT
COMPOUNDS

Name the first elements using
prefix to indicate the number of
atoms present if more than one

DO NOT USE A PREFIX TO
INDICATE ONE ATOM
NAMING COVALENT
COMPOUNDS

Name the second element
 Use prefixes to indicate the
number of atoms present in
the formula
Add "ide" to the end of the
second element

PREFIXES
MONO ----1
 DI
----2
 TRI
----3
 TETRA ----4
 PENTA ----5

HEXA ---- 6
HEPTA ---- 7
OCTA ---- 8
NON ---- 9
DECA ---- 10
PRACTICING COVALENT
COMPOUNDS
1.
2.
3.
4.
5.
N2O3
CS2
P2O5
carbon monoxide
dinitrogen trioxide
ACIDS

Compounds that begin
with an "H"
BINARY ACIDS


Contain only two elements: H and
a nonmetal
To name a binary acid
Begin with the prefix "hydro"
Drop normal ending of
nonmetal name and add "ic"
Add the word "acid"
PRACTICING BINARY
ACIDS
1. HCl
4. hydroiodic acid
2. HF
5. hydrobromic
3. H2S
acid
6. hydrophosphoric
acid
TERNARY ACIDS


Contain three elements: H and
polyatomic ions
To name a ternary acid
–Look at the polyatomic ion name
and if the polyatomic ion name
ends in:
"ate" - change to "ic"
"ite" - change to "ous"
Add the word "acid"

PRACTICING WRITING
TERNARY ACIDS
1.
2.
3.
4.
H2CO3
H2SO4
HNO3
HClO3
5. phosphorous
acid
6. oxalic acid
7. nitrous acid