Polyatomic Naming & Writing

Chemical Nomenclature

PART 2: Naming Writing Formulas for Ionic

Compounds containing Polyatomic Ions

Naming and Writing

Formulas with
Polyatomic Ions

By the end of class I will be able to...

• Name ionic compounds containing Polyatomic Ions using
the IUPAC nomenclature rules

• Write the formula of ionic compounds containing
Polyatomic Ions when given the IUPAC name.

Ex: Al2(SO)3 is Aluminum Sulfate

Terms to Know
- Polyatomic Ion ( Poly = MANY)

Composed of a group of
atoms with one net charge

- Most common Polyatomic Ions

Naming Binary Formulas

1. Write the name of the cation

- If it’s a polyatomic ion, write the name

2. Write the name of the anion.

- If it’s an anion, drop the ending and add -ide
- If it’s a polyatomic ion, write the name.

CRISS-CROSS Method

1. Write the formulas for the cation and polyatomic

ion, including the oxidation number!

2. The oxidation number of the cations and polyatomic

ions will be switched. ( Ignore the + and - signs)

3. Reduce the oxidation numbers if needed.

1

2
Ca2+OH-

Ca(OH)2

Let’s Practice!!!

Multiple Choice

What is the correct charge of Chromium in the formula shown:

CrCl₃

• +1

• +2

• +3

Multiple Choice

What is the correct name for the formula shown:

VF₅

• Vanadium fluoride

• Vanadium (V) fluorine

• Vanadium (V) fluoride

• Vanadium fluorine

Multiple Choice

What is the correct name for the polyatomic ion below?

CO₃^2-

• carbon

• carbide

• carbonate

• carbonite

Multiple Choice

What is the correct formula for sulfate ion?

• SO₃^2-

• SO₄^2-

• SO₂^4-

• SO₂^3-

Multiple Choice

What is the correct formula for the compound named "aluminum nitrate"

• AlNO₃

• Al₃NO₃

• Al(NO₃)₃

• Al₃(NO₃)₃

Multiple Choice

What is the correct formula for the compound named "calcium phosphate"

• CaPO₄

• Ca₂(PO₄)₃

• Ca₃(PO₄)₂

Multiple Choice

What is the correct formula for the compound: "ammonium sulfite"

• NH₄SO₃

• (NH₄)₂SO₃

• (NH₄)₂SO₄

• NH₄(SO₃)₂

Multiple Choice

What is the correct name for the following formula:

CuNO₃

• copper nitrate

• copper (I) nitrate

• copper (II) nitrate

• none of these

Multiple Choice

What is the correct formula for the polyatomic ion called chlorate?

• ClO^–

• ClO₂^–

• ClO₃^–

• ClO₄^–

Multiple Choice

Which of the following is the correct name for the chemical formula Ca(NO₂)₂?

• cadmium nitride
• calcium nitrate
• calcium nitrite
• cadmium nitrite

Multiple Choice

The name of Al₂(SO₄)₃ is

• aluminum sulfur oxide
• aluminum sulfate
• aluminum trisulfate
• aluminum (III) sulfate

Multiple Choice

What is the name of NH₄Cl?

• nitrogen tetrahydrogen chloride
• ammonium chlorine
• ammonium chloride
• ammonium chlorate

Multiple Choice

What is the formula for sodium nitrate?

• Na₃NO
• NaNO
• Na₃NO₃
• NaNO₃

Multiple Choice

What is the formula for iron(II) carbonate?

• Fe₂CO₃
• FeCO₃
• Fe₂CO2
• FeCO4

Multiple Choice

What is the name of K₃PO₄?

• Tripotassium Phosphate
• Tripotassium Phosphite
• Potassium phosphide
• Potassium phosphate

Multiple Choice

Name the following ionic compound: Cr(NO₂)₃

• chromium nitrite
• chromium nitride
• chromium III nitride
• chromium III nitrite

Fill in the Blanks

Hydroxide

Fill in the Blanks

Sulfate

Fill in the Blanks

Phosphite

Fill in the Blanks

nitrate

Fill in the Blanks

acetate

Fill in the Blanks

ammonium

Fill in the Blanks

perchlorate