Naming Ionic Compounds Containing Polyatomic Ions

• For example, we name KNO3 using its cation, K+, potassium, and its polyatomic anion, NO3-, nitrate.

KNO3 potassium nitrate

• We name Fe(OH)2 according to its cation, iron, its charge (II), and its polyatomic ion, hydroxide.

Fe(OH)2 iron(II) hydroxide

• If the compound contains both a polyatomic cation and a polyatomic anion, we use the names of both polyatomic ions.

NH4NO3 ammonium nitrate