How to Name a Chemical Compound
Part of the Chemistry Workbook For Dummies Cheat Sheet
Someone who doesn't know chemistry might think that compounds should already have names, but you know differently. The following steps take you through the process of building a chemical name, using compound XAYB as an example:
Is X hydrogen?
If so, the compound is probably an acid and may use a common name. If X isn't hydrogen, proceed to Step 2.
Is X a nonmetal or a metal?
If X is a nonmetal, then the compound is molecular. For molecular compounds, use numeric prefixes before each element's name to specify the number of each element. If there's only one atom of element X, no prefix is required before the name of X. Use the suffix –ide after the element name for Y. If X is a metal, then the compound is ionic; proceed to Step 3.
Is X a metal that has variable charge?
If X has a variable charge (often, these are group B metals), you must specify its charge within the compound by using a Roman numeral within parentheses between the element names for X and Y. For example, use (II) for Fe2+ and (III) for Fe3+. Proceed to Step 4.
Is Y a polyatomic ion?
If Y is a polyatomic ion, use the appropriate name for that ion. Usually, polyatomic anions have an ending of –ate or –ite (corresponding to related ions that contain more or less oxygen, respectively). Another common ending for polyatomic ions is –ide, as in hydroxide (OH–) and cyanide (CN–). If Y is not a polyatomic ion, use the suffix –ide after the name of Y.