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

• Hg+2 and O-2

• Cr+3 and P-3

• Sn+4 and Cl-1

• Ni+4 and S-2

• Iron (III) phosphide

• Manganese (II) fluoride

• Gold (I) telluride

• Lead (IV) bromide

• Cobalt (III) arsenide

Ionic Compounds

• Sometimes you can use the reverse of the criss-cross method

• When naming compounds,

Naming Ionic Compounds Examples

• Au2S

• MnO

• Fe3N2

• CuCl2

• NiS2

• Cr3P2

• PbF4

• 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, 11-undeca, 12-dodeca.

• To write the formula for binary molecular compounds,

Binary Molecular Compounds Examples

Naming Compounds• SiF2

• C3Cl9

• S4I7

• P5O10

Writing Formulas• Nitrogen trichloride

• Triphosphorus pentoxide

• Hexasulfur monofluoride

• 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 sulfateCa+2 and SO4

-2

• Sodium chlorateNa+1 and ClO3

-1

• Magnesium hydroxideMg+2 and OH-1

• Potassium phosphateK+1 and PO4

-3

• Iron (III) carbonateFe+3 and CO3

-2

• Tin (IV) chromate Sn+4 and CrO4

-2

• Nickel (II) dihydrogen phosphateNi+2 and H2PO4

-1

• Chromium (III) sulfateCr+3 and SO4

-2

• Copper (II) acetateCu+2 and C2H3O2

-1

• Iron (II) permanganateFe+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

• KClO3

• BaSO3

• AlPO4

• CuOH

• Ni3(PO3)4

• Fe(CN)2

• Mn(HCO3)3

• Au2CO3

• Cr2HPO4

AcidsNaming & 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

• HI

• HCN

• H2C4H4O6

Writing Formulas for Acids• Sulfuric acid

• Hydroarsenic acid

• Perchloric acid

• Hypoiodous acid

HydratesNaming & 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