Nomenclature
Chapter 5
Classifying Binary Compounds
• Compounds containing a metal and a nonmetal
are
– Type
• Compounds containing two nonmetals
– Type
• Compounds containing H and a nonmetal =
Metal Cations
• Type I
– Metals that can only
– Determine charge by
• Type II
– Metals that can have
– Determine metal cation’s charge from
Naming Binary Type II Compounds
• Cu+1 and N-3
• Iron (III) phosphide
• Hg+2 and O-2
• Manganese (II) fluoride
• Cr+3 and P-3
• Gold (I) telluride
• Sn+4 and Cl-1
• Lead (IV) bromide
• Ni+4 and S-2
• Cobalt (III) arsenide
Ionic Compounds
• Sometimes you can use the reverse of the
criss-cross method
• When naming compounds,
Naming Ionic Compounds Examples
• Au2S
• NiS2
• MnO
• Cr3P2
• Fe3N2
• PbF4
• CuCl2
• HgI
Type III - Binary Compounds of 2
Nonmetals
•
These binary compounds always start with a
nonmetal or a metalloid.
•
Name first element in formula first,
•
Name the second element in the formula
– However, remember
Type III Binary Molecular Compounds
• Use a prefix in front of
• Never use the prefix mono• Prefixes: 1-mono, 2-di, 3-tri, 4-tetra,5-penta,
6-hexa, 7-hepta, 8-octa, 9-nona, 10-deca, 11undeca, 12-dodeca.
• To write the formula for binary molecular
compounds,
Binary Molecular Compounds
Examples
Naming Compounds Writing Formulas
• Nitrogen trichloride
• SiF2
• C3Cl9
• Triphosphorus pentoxide
• S4I7
• Hexasulfur monofluoride
• P5O10
• Diselenium pentabromide
Figure 5.1: A flow chart for
naming
binary compounds.
Ionic Compounds
• Ternary ionic compounds – contain atoms
of three or more different elements,
usually a polyatomic ion.
• Writing the formulas for ternary
compounds is done in the same way as
binary compounds. The polyatomic ions
stays together though.
Ionic Compounds
• When you need more than one polyatomic
ion in your formula, put parentheses
around the ion, and how many of them you
need outside the parentheses as a
subscript.
• NEVER MOVE SUBSCRIPTS OF THE
IONS, ONLY THE CHARGES!!!
Writing Formulas for Ternary Ionic
Compound Examples
• Calcium sulfate
Ca+2 and SO4-2
• Sodium chlorate
Na+1 and ClO3-1
• Magnesium hydroxide
Mg+2 and OH-1
• Potassium phosphate
K+1 and PO4-3
• Iron (III) carbonate
Fe+3 and CO3-2
• Tin (IV) chromate
Sn+4 and CrO4-2
• Nickel (II) dihydrogen
phosphate
Ni+2 and H2PO4-1
• Chromium (III) sulfate
Cr+3 and SO4-2
• Copper (II) acetate
Cu+2 and C2H3O2-1
• Iron (II) permanganate
Fe+2 and MnO4-1
Ionic Compounds
• When naming ternary compounds, name
the cation (first symbol in the formula
unless it is ammonium, NH4+1) first, and
then the rest of the formula, which will only
have one name, unless it contains
hydrogen.
Naming Ternary Ionic Compounds
• Ca(NO3)2
• Ni3(PO3)4
• KClO3
• Fe(CN)2
• BaSO3
• Mn(HCO3)3
• AlPO4
• Au2CO3
• CuOH
• Cr2HPO4
Acids
Naming & Writing Formulas for Acids
• All acids begin with a hydrogen, and are
neutral compounds.
• In all acids, the cation is the hydrogen ion,
H+1.
• Anions change their endings when they
become acids.
Acids
• -ide ions become hydro root ic acid
• Ex: chloride becomes hydrochloric acid
• -ate ions become root ic acid
• Ex: nitrate becomes nitric acid
• -ite ions become root ous acid
• Ex: chlorite becomes chlorous acid
Acids Naming & Formula
Writing Examples
Naming Acids
• H3PO3
Writing Formulas for Acids
• Sulfuric acid
• HI
• Hydroarsenic acid
• HCN
• Perchloric acid
• H2C4H4O6
• Hypoiodous acid
Hydrates
Naming & Writing Formulas for Hydrates
• Hydrates – compounds that have a certain
number of water molecules attached to
each formula unit.
• To name hydrates, use the same prefixes
you used for naming binary molecular
compounds and add –hydrate after the
prefix.
Hydrates
• To write the formula for compounds
containing hydrates you simply have to
determine how many molecules are
present by looking at the prefix written
before the hydrate.
• If you see a substance where it says it is
anhydrous, that means it does not have
any water molecules attached to each
formula unit.
Naming and Formula Writing
Examples for Hydrates
• CuSO4 5H2O
• FeCl2 3H2O
• Ca3(PO4)2 8H2O
• Sodium thiosulfate tetrahydrate
• Magnesium hydroxide dihydrate
• Stannic nitrate octahydrate