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INTOCHEMISTRY · GENERAL CHEMISTRY

Naming Molecular Compounds

Learn Greek prefixes, formula writing and clear distinctions from ionic naming.

Step-by-step lessonWorked exampleInteractive practiceFree PDF + Word worksheet
Chemical language

Learn the concept, then practice it

Learn Greek prefixes, formula writing and clear distinctions from ionic naming. Start with the illustrated overview, follow the calculation, and try the questions.

Instructional diagram for Naming Molecular Compounds
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Key relationship

binary covalent name = prefix + first element + prefix + second-element -ide

01

Classify first

Two nonmetals often form a binary molecular compound. Unlike simple ionic naming, the compound name usually uses prefixes to show the atom counts.

02

Use prefixes consistently

Mono-, di-, tri-, tetra-, penta-, and hexa- mean 1–6. The first element usually omits mono-; the second element receives an -ide ending.

03

Read the formula

Read element symbols in order, then translate each subscript. Learn common vowel elisions such as monoxide and tetroxide.

WORKED EXAMPLE

Name Nâ‚‚Oâ‚„.

There are two nitrogen atoms (di-) and four oxygen atoms (tetra-); the conventional spelling shortens tetraoxide to tetroxide.

Final answer: dinitrogen tetroxide
!

Common mistake

Do not use Greek prefixes for a simple ionic formula such as CaClâ‚‚, which is calcium chloride.

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