Naming ternary compounds

Ternary compounds are compounds that consist of more than two elements. Most of these compounds involve bonding with polyatomic cations and polyatomic anions. In naming and writing the formulae for ternary compounds, we follow rules that are similar to binary compounds.

Rules for naming ternary compounds:

1. Decide if the metal is a metal with fixed ionic charge or variable charge.
2. Name the metal, following the rules in naming for:
   • metal with fixed ionic charge, or
   • metal with variable charge
3. Name the polyatomic anion following the name of the metal.
4. No Greek prefixes necessary here because the metal charge is either implicitly or explicitly specified and, therefore, in forming a compound, there is only one possible combination with the polyatomic anion.
5. For compounds containing NH₄⁺ cations:
   • Name the cation first followed by the anion (remember that for simple anion, the ending is in -ide).

Examples

Fe₂(SO₄)₃ - iron (III) sulfate or ferric sulfate

Ag₂CO₃ - silver carbonate

Content suitability

BCIT courses: CHEM 0011