Naming & Writing Ionic Compounds

Chemical Nomenclature

PART 1: Naming Writing Formulas for Ionic

Compounds

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

• Name ionic compounds using the IUPAC nomenclature
rules
• Write the formula of ionic compounds when given the
IUPAC name.

Ex: Al2O3 is Aluminum Oxide

Naming Ionic
Compounds

Terms to Know

- Binary Compound

Compound made up of only two types of elements ( NaCl, Fe2O3)

- Cation

An ion with a POSITIVE charge

- Anion

An ion with a NEGATIVE charge

- Polyatomic Ion ( Poly = MANY)

-
A group of atoms that has one net charge.

Naming Binary Formulas

1. Write the name of the cation

2. Write the name of the anion.
3.

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

Naming Ionic Compounds with Transition Metals

1. Write the name of transition metal first.

2. Write the oxidation number (charge) of the transition

metal using roman numerals in parentheses.

3. Write the root name of the nonmetal.

4. Add the ending –ide to the root name of the

nonmetal.

Roman Numerals

1

I

2

II

3

III

4

IV

5

V

6

VI

Multiple Choice

Choose the name of a CuBr₂ compound.

• Copper Bromine

• Copper (II) Bromide

• Lithium iodide

• Cae sium oxide

Multiple Choice

Choose the name of a MgCl₂ compound.

• Magnesium chloride

• Manga nese iodide

• Cupric bromide

• Cae sium oxide

Multiple Choice

Name the ionic compound SnSe₂

• Tin diselenide

• Tin (IV) Selenide

• Tin selenide

• Tin (II) triselenide

Multiple Choice

Name the following ionic compound: BeCl₂

• beryllium chlorine

• beryllium II chloride

• beryllium chloride

• beryllium dichloride

Multiple Choice

Name this compound: 
KF

• Potassium fluoride
• Potassium fluorite
• Fluorine potasside 
• Potassium fluorate

Multiple Choice

Which of these combinations is an ionic compound made of?

• Metal and Metal

• Nonmetal and Nonmetal

• Metal and Nonmetal

• Cation and Cation

Multiple Choice

When naming a compound, which of these is written first?

• Metal

• Nonmetal

• Anion

• Cation

Multiple Choice

When naming a compound, what must the last part be?

• the element with "ide" at the end

• the element with the ending "ite"

• the name of the element

• the element with "ide" at the end, unless its a polyatomic ion

Multiple Choice

If I gain electrons I become

• Positive because I've added to my atom

• negative because I've added electrons

• same because i'm balanced

• equal because now I have electrons

Multiple Choice

Correctly name the compound Ba₃P₂

• barium phosphide

• barium phosphorus

• barium(II) phosphide

• tribarium diphosphide

Multiple Choice

What is the name of the binary ionic compound of calcium and sulfur?

• calcium sulfur

• The formula must be known in order to correctly name the compound.

• . calcide sulfide

• calcium sulfide

Multiple Choice

Correctly name the compound Rb₂O

• dirubidium oxygen

• rubidium oxygen

• dirubidium oxide

• rubidium oxide

Writing Formulas for

Ionic Compounds

Oxidation Numbers

●To understand writing formulas for
Ionic Compounds, we must first be able
to identify an element’s oxidation number.

●The oxidation number of an element is
the number of valence electrons that
an atom will gain or lose.

●Recall that metals will give up electrons
making them a cation ( positively
charged) and nonmetals will take
electrons making them an anion (
negatively charged)

Quick Practice: Oxidation numbers

●What is the charge on the following elements?

○ Oxygen

○ Magnesium

○ Chromium ( III)

○ Chlorine

○ Potassium

○ Sulfur

○ Tin (III)

Quick Practice: Oxidation numbers

●What is the charge on the following elements?

○ Oxygen

2-

○ Magnesium

2+

○ Chromium ( III)

3+

○ Chlorine

1-

○ Potassium

1+

○ Sulfur

2-

○ Tin (III)

3+

CRISS-CROSS Method

1. Write the formulas for the cation and anion, including

the oxidation number!

2. The oxidation number of the cations and anions will

be switched. ( Ignore the + and - signs)

3. Reduce the oxidation numbers if needed.

1

2
Ca2+Cl-
CaCl2

Let’s Practice!!!

Multiple Choice

A method that can be used to write correct formulas for ionic compounds is called the _____ method.

• neutralization

• ion switching

• crisscross

• subscript

Multiple Choice

What is the correct formula for the compound, lithium oxide?

• LiO
• Li₂O
• LiO₂
• Li₂O₂

Multiple Choice

What is the formula for manganese(III) oxide?

• MgO
• Mg₂O₃
• MnO
• Mn₂O₃

Multiple Choice

The chemical formula of Iron (III)bromide is

• FeBr
• Fe(III)Br
• FeBr₃
• Fe₂Br₃

Multiple Choice

Write the formula for copper(I) phosphide

• Cu₃P
• CuP
• Cu₁P
• CuP₃

Multiple Choice

What is the formula for manganese(III) oxide?

• MgO
• Mg₂O₃
• MnO
• Mn₂O₃

Multiple Choice

How do the following two elements bond together?
K¹⁺  S^2- 

• KS
• K₈S
• K₆S₃
• K₂S