Types of Compounds

The following summarizes the distinguishing features of different kinds of formulas and names.

Binary Covalent Compounds

General Formula  -  AaBb   -  For example, N2O5 or CO2  

General Name - (prefix unless mono)(name of first element in formula) (prefix)(root of second element)ide
                            For example, dinitrogen pentoxide or carbon dioxide

Binary Ionic Compounds

General Formula - MaAb   -  For example, NaCl or FeCl3

General Name - (name of metal) (root of nonmetal)ide or (name of metal)(Roman #) (root of nonmetal)ide
                            For example, sodium chloride or iron(III) chloride

Ionic Compounds with Polyatomic Ion(s)

General Formula - MaXb or (NH4)aXb   X = recognized formula of polyatomic ion
                                For example, Li2HPO4 or CuSO4 or NH4Cl or (NH4)2SO4

General Name - (name of metal) (name of polyatomic ion) or (name of metal)(Roman #) (name of polyatomic ion) or ammonium (root of nonmetal)ide or ammonium (name of polyatomic ion)
                            For example, lithium hydrogen phosphate or copper(II) sulfate or ammonium chloride or ammonium sulfate

Binary Acids

General Formula - HX(aq)   -  For example, HCl(aq)

General Name - hydro(root)ic acid   -  For example, hydrochloric acid


General Formula - HaXbOc   -  For example, HNO3 or H2SO4 or H3PO4

General Name - (root)ic acid   -  For example, nitric acid or sulfuric acid or phosphoric acid

The following links take you to pages that have information about writing names and formulas for compounds.

Binary Covalent Nomenclature

Ionic Nomenclature

Cation Names and Formulas

Anion Names and Formulas

Acid Nomenclature

General Nomenclature