Polyatomic Ions and Naming Compounds

What is the correct name for the compound Fe2(SO4)3?

Which of the following is a correct statement about polyatomic ions?

What is the charge of the phosphate ion, PO4?

What is the correct name for the compound Cu(NO3)2?

Which of the following compounds contains a transition metal?

What is the correct name for the compound $Ca(ClO_4)_2$?

What is the chemical formula for ammonium phosphate?

Which of the following correctly describes the ion $SO_3^{2-}$?

What is the correct chemical formula for iron(II) carbonate?

Polyatomic Ions

Polyatomic ions are ions comprised of multiple atoms.
They act as a single unit, indivisible.
Each has a specific name and charge.
Examples include: chromate ($CrO_4^{2-}$), carbonate ($CO_3^{2-}$), perchlorate ($ClO_4^-$), oxalate ($C_2O_4^{2-}$), sulfate ($SO_4^{2-}$), phosphate ($PO_4^{3-}$), and ammonium ($NH_4^+$).
Use the ion's name from the list.
Use the "-ide" suffix for monoatomic anions (Groups 15, 16, and 17).
Be sure the whole polyatomic ion is enclosed in parentheses if there's more than one. The subscript for the number of the polyatomic ion appears after the parenthesis.

Naming Compounds with Polyatomic Ions

Identify if the compound contains a transition metal (d-block elements).
If a transition metal is present, use Roman numerals to show the metal's charge.
Use the name of the polyatomic ion from the list.
Monoatomic anions use the "-ide" suffix.

Writing Chemical Formulas with Polyatomic Ions

Follow the same steps as for monoatomic ions.
For transition metals, determine their charge and use the Roman numeral.
Enclose polyatomic ions in parentheses and place the subscript outside the parenthesis. This indicates the number of times the polyatomic ion is present in the compound.

Naming Examples

$Li_2SO_4$ : Lithium sulfate (lithium is not a transition metal).
$FePO_4$ : Iron(III) phosphate (Iron has a 3+ charge).
$NH_4S$ : Ammonium sulfide.

This quiz covers the principles of polyatomic ions and how to name compounds containing them. You'll learn about the charges of polyatomic ions, the role of transition metals, and how to properly use Roman numerals in naming. Test your understanding of chemical formulas and naming conventions.