Naming Ionic Compounds and Molecules

Introduction to Naming Ionic Compounds

Background

Ionic compounds consist of a cation (positively charged particle) and an anion (negatively charged particle). These compounds can be represented by either names or formulas using element symbols and subscripts. A systematic set of rules exists for naming and writing chemical formulas so that all scientists are consistent. This activity serves as an introduction to some of those rules.

Open Ended

What is the difference between a covalently-bonded (molecular) compound and an ionic compound?

Open Ended

What portion of the periodic table tends to form cations? Anions?

​Problem:

​What patterns exist in naming ionic compounds?

Part A:

Group your Ionic Compound Name Cards into two sensible categories of 3 cards each and discuss a heading for each category.

Open Ended

Group 1 grouping: Summarize how you group your compounds into two different categories

​Part A - Part 2:

Rearrange the cards into two different groups of 3 cards using different category headings.

Open Ended

Group 2 grouping: Summarize how you group your compounds into two different categories.

Match

Match the following Ionic Compounds Name and Formulas

• Aluminum Oxide

• Tin (II) Nitrate

• Magnesium Phosphide

• Calcium

  Sulfate

• Iron (III) Chlorate

Al₂O₃

Sn(NO₃)₂

Mg₃P₂

CaSO₄

Fe(ClO₃)₃

• Al₂O₃

• Sn(NO₃)₂

• Mg₃P₂

• CaSO₄

• Fe(ClO₃)₃

Open Ended

Summarize any patterns observed between each name and formula below:

Match

Match the following Ionic Compounds Name and Formulas

• Iron (III) Chloride

• Copper (II) Nitrate

• Potassium Phosphide

• Calcium

  Sulfide

• Iron (II) Chlorate

FeCl₃

Cu(NO₃)₂

K₃PO₄

CaS

Fe(ClO₃)₂

• FeCl₃

• Cu(NO₃)₂

• K₃PO₄

• CaS

• Fe(ClO₃)₂

Open Ended

What contradictions can you find in the early summary statements? Please discuss,

Open Ended

Write a one or two sentence summary of the general patterns that exist in naming ionic compounds based on the activity.

Representative elements have predictable charges.

​Metal names will always GO FIRST

• Metal names STAY THE SAME

​Non-metals

• Non-metals get a change name when they bond with Metals.

​Non-metals

• Non-metals name will change with a new -IDE ending

​Non-metals --> Bonded Anions

• Hydrogen --> HydrIDE

• Carbon --> CarbIDE

• ​Nitrogen --> NitrIDE

• ​Oxygen --> OxIDE

• ​Fluorine --> FluorIDE

• ​Phosphorus --> PhosphIDE

• ​Sulfur --> SulfIDE

• ​Chlorine --> ChlorIDE

• ​Selenium --> SelenIDE

• ​Bromine --> BromIDE

• ​Iodine -> IodIDE

• Non-metals will always be ​LISTED LAST

​Metal FIRST --> Non-Metal LAST + IDE

• Example: Table Salt

​

• NaCl = Chemical FORMULA

​

​Metal FIRST --> Non-Metal LAST + IDE

• Example: Table Salt

​

• NaCl = Chemical FORMULA

​

​Sodium ChlorIDE = Chemical NAME

Test your knowledge!​

A Periodic Table will help you!

Take one more look at the new -IDE anion names before you play:

Test your knowledge!​

Multiple Choice

Sodium + Nitrogen

• Sodide Nitride

• Sodium Nitrogide

• Sodide Nitrate

• Sodium Nitride

Multiple Choice

Sodium + Oxygen

• Sodide Oxyide

• Sodium Oxide

• Sodium Oxyide

• Sodium Oxygenide

Multiple Choice

Sodium + Phosphorous

• Sodium Phosphide

• Sodium Phosphoride

• Sodium Pho-Slo

• Sodium Phone Home

Multiple Choice

Nitrogen (#7) is the name of the element. Nitride is the name of the

• N ^3-

  Bonded

  Group 14 anion

• N ^3-

  Bonded

  Group 15 anion

• N ^3-

  Bonded

  Group 16 anion

• N ^3-

  Bonded

  Group 17 anion

​Transitional Metals

Rules in naming transitional ionic compounds

1. name first the cation before the anion

2. for those with 2 or more oxidation, we identify the oxidation in writing the name of the compound

example: Copper (II) oxide or Copper (I) oxide

Transitional Binary compounds of metal/nonmetal

Transitional metals combine with nonmetals to give ionic compounds. When naming binary ionic compounds, name the cation first (specifying the charge for transitional metals), then the nonmetal anion (element stem + -ide).

Stock System

• Most transition metals and large p block metals have variable charge

• Roman numeral used to indicate the charge of the cation

• Exceptions to stock system (do not use the roman numeral): Groups 1 & 2, Ag⁺¹, Zn⁺², Cd⁺², Al⁺³

Examples

NaCl- Sodium chloride

CuCl₂ - Copper (II) Chloride
CuCl - Copper (I) Chloride

Ternary compounds (polyatomic ions)

Name the cation first (specifying the charge, if necessary), then the polyatomic ion as listed in the table above (or as derived from the rules which were given).

Do NOT use prefixes to indicate how many of each element is present

Examples

Ca(NO₃)₂-Calcium nitrate

Mg(BrO₃)₂-Magenisum Bromate

K₃PO₄-Potassium phosphate
Cu₃(PO4)₂ - Copper (II) Phosphate

​QUESTIONS?