Chapter 4 Nomenclature

4.1 Naming Compounds that contain a Metal and a Nonmetal

Binary Ionic Compound

Type I Compounds

Cation is always named 1st, and the anion second

A simple cation takes its name from the element.

A simple anion is named with the root of the element name and adding the suffix –ide.

Examples:

CsF AlCl3 MgI2

Rb2O SrI2 K2S

Table 4.1

Type II Compounds

Older nomenclature: the cation with the higher charge ends in –ic

the cation with the lower charge ends in –ous.

Examples:

CuCl CuCl2

Stock system- naming system using Roman numerals in parentheses for the charges; no other suffixes are needed (This is the most commonly used system)

Examples:

CuCl HgO Fe2O3

MnO2 PbCl4

Table 4.2

4.2 Naming Binary Compounds that contain only Nonmetals (Type III)

Prefixes:

Mono- hexa-

Di- hepta-

Tri- octa-

Tetra- nona-

Penta- deca-

(Sometimes it is appropriate to eliminate an extra vowel sound: decaoxide to decoxide)

Do not use prefix for mono- on 1st element if it is only one.

Continue to use suffix –ide on second element name

Examples:CCl4 NO2 IF5

BF3 NO N2O5

Figure 4.1: A flow chart for naming binary compounds.

4.4 Naming Compounds that contain Polyatomic Ions

YOU MUST MEMORIZE THESE!!

Oxyanions: hypochlorite

chlorite

chlorate

perchlorate

Examples:

Na2SO4 KH2PO4 Fe(NO3)3

Mn(OH)2 Na2SO3 Ca(OH)2

Na3PO4 KMnO4 (NH4)2Cr2O7

Co(ClO4)2 KClO3 Ca(NO2)2

Table 4.4

Figure 4.2: Overall strategy for naming chemical compounds.

4.5 Naming Acids

Binary Acid (no oxygen). Use prefix hydro-, and suffix –ic

Examples:

HCl HBr HI

H2S H2Se HF

Tertiary acids (oxygen present)

If anion ends in –ite, acid ends in –ous.

If anion ends in –ate, acid ends in –ic.

Examples:HNO3 HNO2

HC2H3O2 H2SO4 H2SO3

H3PO4 H3PO3 HClO

HClO2 HClO3 HClO4

4.6 Writing Formulas from Names

Criss-cross method (always check that a neutral compound is made)

(You cannot reduce subscripts that would change a polyatomic ion)

(BUT you should reduce subscripts in other cases)

Magnesium oxide tin(II)oxide tin(IV)oxide

Examples: potassium hydroxide sodium carbonate

Cobalt (III) nitrate calcium chloride lead (IV) oxide

Dinitrogen pentoxide ammonium perchlorate

Ammonium sulfate vanadium (V) fluoride

Disulfur dichloride rubidium peroxide

Aluminum oxide