IPC Notes Polyatomic Ion Names & Formulas

Polyatomic Ions A polyatomic ion is a charged covalently bonded group of atoms. ex) sulfate is SO 4 -2

Common Polyatomic Ions Nitrate = NO 3 -1 Sulfate = SO 4 -2 Phosphate = PO 4 -3 Ammonium = NH 4 +1 Carbonate = CO 3 -2 Hydroxide = OH -1

Common Polyatomic Ions Nitrate = NO 3 -1 Sulfate = SO 4 -2 Phosphate = PO 4 -3 Ammonium = NH 4 +1 Carbonate = CO 3 -2 Hydroxide = OH -1 NOTE: There are many more polyatomic ions that this short list. You will use about 30 of them in Chemistry.

Writing Formulas 1)Write the symbol of the first ion with its oxidation number. 2)Write the symbol of the second ion with its oxidation number.

Writing Formulas 3) Criss cross the numbers, not the + or – sign. 4) If a subscript needs to be used with a polyatomic ion, write parenthesis around the polyatomic ion first and then put the subscript at the bottom right.

Writing Formulas Write the formula for: aluminum sulfate

Writing Formulas Write the formula for: potassium nitrate

Writing Formulas Write the formula for: calcium phosphate

Writing Formulas Write the formula for: magnesium hydroxide

Writing Formulas Write the formula for: calcium carbonate

Writing Formulas Write the formula for: ammonium phosphate

Writing Names 1)Write the name of the first ion. 2)Write the name of the second ion. If the second ion is a polyatomic ion, leave the name alone. If the second ion is just an element, change the ending to –ide.

Naming Compounds Write the name for: MgSO 4

Naming Compounds Write the name for: KNO 3

Naming Compounds Write the name for: Al 2 (CO 3 ) 3

Naming Compounds Write the name for: NH 4 F

Naming Compounds Write the name for: NH 4 NO 3

Naming Compounds Write the name for: Ca(OH) 2