Nomenclature

Chapter 5

Classifying Binary Compounds

• Compounds containing a metal and a nonmetal are binary ionic– Type I and II

• Compounds containing two nonmetals– Type III

• Compounds containing H and a nonmetal = Acids

Type III - Binary Compounds of 2 Nonmetals

• These binary compounds always start with a nonmetal or a metalloid. That’s the easiest way to identify them. They will contain no metals!

• Name first element in formula first, use the full name of the element

• Name the second element in the formula as if it were an anion– However, remember these compounds do not contain

ions, so DO NOT USE THE CRISS-CROSS METHOD!!!

Type III Binary Molecular Compounds

• Use a prefix in front of each name to indicate the number of atoms

• Never use the prefix mono- on the first element• 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, write the number next to the compound if there is a prefix, if not just write the symbol itself.

Binary Molecular Compounds Examples

Naming Compounds

• SiF2 - silicon difluoride

• C3Cl9 - tricarbon nonachloride

• S4I7 – tetrasilicon heptaiodide

• P5O10 – pentaphosphorus octoxide

Writing Formulas

• Nitrogen trichloride – NCl3

• Triphosphorus pentoxide - P3O5

• Hexasulfur monofluoride - S6F

• Diselenium pentabromide – Se2Br5

Metal Cations

• Type I – Metals that can only have one possible charge– Determine charge by position on the Periodic

Table

• Type II– Metals that can have more than one possible

charge– Determine metal cation’s charge from the

charge on anion

Type II Binary Ionic Compounds

• Contain Metal Cation + Nonmetal Anion• Metal listed first in formula & name• Name metal cation first, name nonmetal anion

second• Metal cation name is the metal name followed by

a Roman Numeral in parentheses to indicate its charge– Determine charge from anion charge– Common Type II cations in Table 5.2 (page 128 or on

Week #3 Ions & Symbols List)• Nonmetal anion named by changing the ending

on the nonmetal name to -ide

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 to determine the charges for the transition metals.

• When naming compounds, you do not need to tell how many atoms of each ion are present.

Naming Ionic Compounds Examples

• Au2S

• MnO

• Fe3N2

• CuCl2

• NiS2

• Cr3P2

• PbF4

• HgI

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 hydroxideMg+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

• KClO3

• BaSO3

• AlPO4

• CuOH

• Ni3(PO3)4

• Fe(CN)2

• Mn(HCO3)3

• Au2CO3

• 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

• HI

• HCN

• H2C4H4O6

Writing Formulas for Acids• Sulfuric acid

• Hydroarsenic acid

• Perchloric acid

• Hypoiodous acid

Hydrates

• Hydrates are when you have a certain number of water molecules attached to a compound (usually an ionic compound)

• The number of water molecules is shown after the formula for a compound and separated from the remainder of the compound by a dot.

Hydrates

• Use the same prefixes as you did when naming binary molecular compounds to tell how many water molecules are present in a hydrate (1 = mono, 2 = di, …)

• An anhydrous compound is one that contains no water molecules.

Hydrate Examples

• CuSO4 . 5H2O

• Mg(NO3)2 . 3 H2O

• Barium chloride dihydrate

• Ammonium acetate octahydrate

Basic Organic Compounds

• You will need to know the names of the first 10 alkanes (hydrocarbons containing only single bonds).

• The generic formula of these alkanes is:

•CnH2n+2

Basic Organic Compounds

• Methane – CH4

• Ethane – C2H6

• Propane – C3H8

• Butane – C4H10

• Pentane – C5H12

• Hexane - C6H14

• Heptane - C7H16

• Octane - C8H18

• Nonane - C9H20

• Decane - C10H22