Naming Compounds Flow Chart (Page 2 of 2) in pdf

More than two elements – Polyatomic ions

Write the name of the cation and then the name of the anion. Be careful with the names, one

number change produces a different name. If the formula has a charge the word “ion” must

appear in the name. If the formula does not have a charge, the word “ion” must not appear in

the name.

Cation Help

is ammonium ion. Transition metals and the metals to the right of the transition metals

on the periodic table require a roman numeral in the name to indicate the oxidation state of the

metal except for zinc, cadmium and silver. Alkali metals, alkaline earth metals and aluminum

do not get roman numerals.

example: Fe

is iron (III) ion Al

is aluminum ion Ag

is silver ion Na

is sodium ion

Anion Help

1. You must memorize the 13 “standard” anions, both the number of atoms and the charge. Most

of these end in “ate”, the two exceptions are hydroxide ion (OH

) and cyanide ion (CN

2. If there is one more oxygen than the “standard” ion the prefix of “per” is added to the name.

Example chlorate ion is ClO

so if the ion you are considering is ClO

the name is perchlorate

ion.

3. If there is one less oxygen than the “standard” ion the “ate” ending is changed to an “ite”

ending. Example: chlorate ion is ClO

so if the ion you are considering is ClO

the name is

chlorite ion.

4. If there is two less oxygens than the “standard” ion, a “hypo” prefix is added and the “ate”

ending is also changed to an “ite” ending. Example: chlorate ion is ClO

so if the ion you are

considering is ClO

the name is hypochlorite ion.

5. If there is a hydrogen attached to the “standard” ion (also changing the charge by +1) a prefix

of “bi” or “hydrogen” is used to indicate this. Example: sulfate ion is SO

so HSO

is bisulfate

ion or hydrogen sulfate ion.

6. If the anion is a single element change the name to end in “ide”. Example NH

Cl the name of

the anion is chloride ion. The name of the compound is ammonium chloride.

Naming Compounds Flow Chart Page 2