Naming Compounds
IONIC, COVALENT AND ACIDS
A. Ionic Nomenclature
Ionic Formulas
 Write each ion, cation first. Don’t show charges in
the final formula.
 Overall charge must equal zero.
 If charges cancel, just write symbols.
 If not, use subscripts to balance charges.
 Use parentheses to show more than one polyatomic
ion.
 Stock System - Roman numerals indicate the ion’s
charge.
A. Ionic Nomenclature
Ionic Names
 Write the names of both ions, cation first.
 Change ending of monatomic anions
to -ide.
 Polyatomic ions have special names.
 Stock System - Use Roman numerals to show the
ion’s charge if more than one is possible. Overall
charge must equal zero.
A. Ionic Nomenclature
 Consider the following:
 Does it contain a polyatomic ion?
-ide, 2 elements no
 -ate, -ite, 3+ elements


Does it contain a Roman numeral?


yes
Check the table for metals not in Groups 1 or 2.
No prefixes!
A. Ionic Nomenclature
Common Ion Charges
1+
0
2+
3+ NA 3- 2- 1Multiple Oxidation States
Exceptions Ag+1, Zn+2, Cd+2
A. Ionic Nomenclature
potassium chloride
K+ Cl
magnesium nitrate
Mg2+ NO3
copper(II) chloride
Cu2+ Cl
KCl
Mg(NO3)2
CuCl2
A. Ionic Nomenclature
NaBr
sodium bromide
Na2CO3
sodium carbonate
FeCl3
iron(III) chloride
B. Molecular Nomenclature
 Prefix System (binary compounds)
1.
Less e-neg atom
comes first.
2. Add prefixes to indicate # of atoms. Omit mono- prefix on
first element.
3.
Change the ending of the
second element to -ide.
4.
Metalloids will typically bond covalently with other
nonmetals. (Has to do with difference in electronegativity)
B. Molecular Nomenclature
PREFIX
monoditritetrapentahexaheptaoctanonadeca-
NUMBER
1
2
3
4
5
6
7
8
9
10
B. Molecular Nomenclature
CCl4
carbon tetrachloride
N2O
dinitrogen monoxide
SF6
sulfur hexafluoride
B. Molecular Nomenclature
arsenic trichloride
AsCl3
dinitrogen pentoxide
N2O5
tetraphosphorus decoxide
P4O10
B. Molecular Nomenclature
 The Seven Diatomic Molecules
Br2 I2 N2 Cl2 H2 O2 F2
H
Named the same as the element
H2 is Hydrogen
etc….
Cl2 is chlorine
N O F
Cl
Br
I
C. Acid Nomenclature
 Acids are compounds that form H+ ions in solution. Therefore
they will all start with H.
 There are 3 acid naming scenarios:
HCl is a binary acid. All binary acids are named the same
way:
1.




the prefix "hydro" is used.
the root of the anion is used.
the suffix "ic" is used.
the word "acid" is used as the second word in the name.
 The name for HCl is hydrochloric acid.
 Other binary acids: HF, HBr, HI, and H2S.
C. Acid Nomenclature
2. HClO is an acid involving a polyatomic ion. The
polyatomic ion is ClO¯ and its name is
hypochlorite.

Any time you see the "ite" suffix, you change it to "ous" and
add the word acid.
 The name of HClO is hypochlorous acid.
 Other “ous” acids: HNO2, H2SO3
C. Acid Nomenclature
HClO3 has the ClO3¯ polyatomic ion and its name
is chlorate.
1.

Any time you know the "ate" ending is used on the
polyatomic, you use "ic" when you write the corresponding
acid formula.
 The name of HClO3 is chloric acid.
 Other “ate” acids: H3PO4, HNO3, H2CO3
C. Acid Nomenclature
 Name the following:
 HBr
 HBrO3
 H2SiO3
 H3AsO3
C. Acid Nomenclature
 Write the formula for the following:
 Phosphorus acid
 Hydroselenic acid
 Oxalic acid