Nomenclature Examples in Chemistry

Start with the recap, study the fully worked examples, then use the practice problems to check your understanding of Nomenclature.

This page combines explanation, solved examples, and follow-up practice so you can move from recognition to confident problem-solving in Chemistry.

Concept Recap

The systematic method for naming chemical compounds according to IUPAC (International Union of Pure and Applied Chemistry) rules, ensuring that every compound has exactly one.

Chemistry has a naming system so that every compound gets exactly one name and every name points to exactly one compound — like a universal address system.

Read the full concept explanation →

How to Use These Examples

  • Read the first worked example with the solution open so the structure is clear.
  • Try the practice problems before revealing each solution.
  • Use the related concepts and background knowledge badges if you feel stuck.

What to Focus On

Core idea: Ionic compounds: metal name + nonmetal with -ide suffix. Acids: hydro-...-ic or ...-ic/-ous. Covalent: Greek prefixes (mono-, di-, tri-).

Common stuck point: Transition metals need Roman numerals to show their charge: FeCl₂ is iron(II) chloride, FeCl₃ is iron(III) chloride.

Sense of Study hint: When naming a compound, first classify it as ionic, covalent, or an acid. For ionic compounds, write the metal name first, then the nonmetal with an '-ide' ending; use Roman numerals for transition metals with variable charges. For covalent compounds, use Greek prefixes (mono-, di-, tri-) before each element name. For acids, use 'hydro-...-ic acid' for binary acids and '-ic' or '-ous acid' for oxyacids.

Worked Examples

Example 1

easy
Name the following ionic compounds: (a) NaCl, (b) \text{CaO}, (c) \text{FeCl}_3.

Solution

  1. 1
    (a) Na = sodium, Cl = chloride → sodium chloride.
  2. 2
    (b) Ca = calcium, O = oxide → calcium oxide.
  3. 3
    (c) Fe can have multiple charges. With 3 Cl^-, Fe must be +3. → iron(III) chloride.

Answer

\text{(a) sodium chloride, (b) calcium oxide, (c) iron(III) chloride}
For ionic compounds, name the cation first and then the anion (with -ide ending). Transition metals require Roman numerals to indicate their charge since they can form multiple ions.

Example 2

medium
Name these covalent compounds: (a) \text{CO}_2, (b) \text{N}_2\text{O}_4, (c) \text{PCl}_5.

Practice Problems

Try these problems on your own first, then open the solution to compare your method.

Example 1

easy
Write the chemical formula for: (a) potassium bromide, (b) aluminum oxide.

Example 2

hard
Name the following compounds: (a) \text{FeCl}_3, (b) \text{N}_2\text{O}_5, (c) \text{Cu}_2\text{O}. Explain the naming convention used for each.
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Related Concepts

Formula WritingIon

Background Knowledge

These ideas may be useful before you work through the harder examples.

formula writingion