Polyatomic Ion Compounds
Polyatomic Ions The same principles and rules are followed in forming and naming polyatomic ion compounds. However, parenthesis must be used to keep charges separate.
K NO 3 - Determine the charges: K + NO 3 - Criss-Cross: KNO 3 Naming: Keep the first (positive) ion the same and for the second (negative) ion 1.) keep the same if it is a polyatomic or 2.) drop the ending and add –ide if it is a single element. Potassium Nitrate
Na SO 3 2- Na + SO 3 2- Na 2 SO 3 Sodium Sulfite
Ca SO 3 2- Ca 2+ SO 3 2- CaSO 3 Calcium Sulfite
Al C 2 H 3 O 2 - Al 3+ C 2 H 3 O 2 - Al(C 2 H 3 O 2 ) 3 Aluminum Acetate
NH 4+ PO 4 3- (NH 4 ) 3 PO 4 Ammonium Phosphate
Fe 3+ OH - Fe(OH) 3 Iron(III) Hydroxide