Nomenclature
A Systematic Approach to Naming
Chemical Compounds
Nomenclature
Ternary Ionic Compounds
Binary and Ternary Acids
Ternary Ionic Compounds
>2 elements
cation with an anion
Metal cation with polyatomic anion
Na2SO4
sodium sulfate
Polyatomic cation with monatomic anion
NH4Cl
ammonium chloride
Polyatomic cation with polyatomic anion
NH4NO3
ammonium nitrate
Some Common Polyatomic Anions
nitrate
chlorate
NO3ClO3-
carbonate
CO32-
sulfate
SO42-
phosphate
PO43-
Some Common Polyatomic Anions
nitrate
NO3nitrate chlorate
ClO3chlorate carbonate
NO3ClO3-
CO32carbonatesulfate
SO42sulfate
phosphate
phosphate PO43-
SO42-
CO32-
PO43-
Some Common Polyatomic Anions
nitrate
NO3-
ClO3carbonate CO32SO42sulfate
phosphate PO43chlorate
nitrite
NO2-
chlorite
ClO2-
SO32sulfite
phosphite PO33-
Notice that renaming ‘-ate’ to ‘-ite’ simply reduces the
number of oxygen atoms but not ionic charge
Some Common Polyatomic Anions
Some polyatomic anions can have even 1 less oxygen
nitrate
NO3-
ClO3carbonate CO32SO42sulfate
phosphate PO43chlorate
nitrite
NO2-
chlorite
ClO2-
SO32sulfite
phosphite PO33-
Notice that renaming ‘-ate’ to ‘-ite’ simply reduces the
number of oxygen atoms but not ionic charge
Some Common Polyatomic Anions
Some polyatomic anions can have even 1 less oxygen
nitrate
NO3--
chlorate
ClO3-- chlorite
ClO- 2chlorite ClO
ClO3
2
2CO
CO3322- 2SO442-2- sulfite
SO
SO
3 3
sulfite SO
3PO33- 3PO
phosphite
34
PO4
phosphite PO3
nitrate
chlorate
carbonate
carbonate
sulfate
sulfate
phosphate
phosphate
NO3
nitrite
nitrite
NO- 2-
NO2
Some Common Polyatomic Anions
Some polyatomic anions can have even 1 more oxygen
perchlorate ClO4-
nitrate
NO3-
nitrite
NO2-
chlorate
carbonate
sulfate
phosphate
ClO3CO32SO42PO43-
chlorite
ClO2-
sulfite
phosphite
SO32PO33-
hypochlorite ClO-
The halo-oxo-anions of Br and I have identical naming schemes
Some Common Polyatomic Anions
perchlorate
perchlorate
periodate ClO
IO4-44-perbromate
BrO
nitrate
chlorate
iodate
bromate
carbonate
sulfate
phosphate
NO3- -ClO
IO
ClO
BrO
3 33
CO32SO42PO43-
NO2-
nitrite
chlorite
iodite
bromite
chlorite
- -- - --- hypochlorite
IO
ClO
hypoiodite
BrO
IO
hypobromite
BrO
ClO
hypochlorite ClO
ClO
2 222
sulfite
phosphite
SO32PO33-
The halo-oxo-anions of Br and I have identical naming schemes
Ternary Ionic Compounds
Examples
Write the chemical formula of aluminum sulfate
Aluminum sulfate
Al3+
SO42-
2(3+)
?(3+) + 3(2-)
?(2-) = 0
Al2(SO4)3
Ternary Ionic Compounds
Examples
Write the systematic name for Cu(NO3)2
Cu(NO3)2
(?+) + 2(-1) = 0
(2+)
?+
Cu2+
NO3-
Copper is a transition element so use Stock
convention for naming the metal ion:
copper(II) nitrate
Some Common Polyatomic Anions
A Few Exceptions
hydroxide
cyanide
OHCN-
azide
N3-
carbide
C22-
Despite being polyatomic anions, the rules of
nomenclature for monoatomic ions apply.
Binary and Ternary Acids
A binary acid is molecular compound which dissociates into
hydrogen ion and a monoatomic anion in aqueous solution.
A ternary acid is molecular compound which is a combination
of hydrogen ion and a polyatomic anion.
Binary Acids
Prefix the root name of the anion with ‘hydro’
Transform the suffix of the anion from ‘-ide’ to ‘-ic’
Add the word ‘acid’
EXAMPLES
HCl(g)
hydrogen
Read
the formula
chloridecarefully!
HCl(aq) hydrochloric acid
HI(g)
hydrogen iodide
HI(aq)
hydroiodic acid
Binary Acids
An Exception
HCN(g) hydrogen cyanide
HCN(aq) Read
hydrocyanic
the molecular
acid name carefully
Even though it is not a binary acid, the ‘-ide’ ending of the
anion requires application of the binary acid rule.
Ternary Acids
Transform the suffix of the anion from ‘-ate’ to ‘-ic’ -orTransform the suffix of the anion from ‘-ite’ to ‘-ous’
Add the word ‘acid’
Never use the prefix ‘hydro’ for ternary acids
EXAMPLES
HNO3
nitric acid
HNO2
nitrous acid
Ternary Acids
The name does not include ‘acid’ until the anion’s ionic
charge is completely balanced by hydrogen ion.
EXAMPLE
Na2SO4
sodium sulfate
NaHSO4 sodium hydrogen sulfate
H2SO4
sulfuric acid
Review of Basic Nomenclature
Binary Ionic Compounds
CuCl2
copper(II) chloride
barium oxide BaO
Binary Molecular Compounds
N2O4
dinitrogen tetraoxide
sulfur hexafluoride SF6
Ternary Ionic Compounds
MnSO4 manganese(II) sulfate
aluminum nitrate Al(NO3)3
Acids
HCl(aq) hydrochloric acid
perchloric acid
HClO4