Naming chemical compounds is hard at first but you will eventually get the hang of it. You might even become a master of naming chemical compounds!

I will first teach you how to name chemical compounds then I will give you a practice quiz afterwards.

Step 1. Identify Which Type the Compound Belongs

There are three types of three types of chemical compounds that we can easily name:

  1. Binary Acids – hydrogen and a halogen (HF, HCl, HBr and HI only!)
  2. Ionic Compounds – metal and a nonmetal
  3. Covalent Compounds – both nonmetals
Examples: 
  • HCl is a binary acid
  • NaCl is an ionic compound
  • CO2 is a covalent compound

Step 2. Name the Compound According to These Steps

Naming Binary Acids

  1. Write Hydro + root of second element + ic for the first word
  2. Write acid for the second word
Examples:
  • HCl is Hydrochloric acid
  • HBr is Hydrobromic acid

Naming Ionic Compounds

For naming ionic compounds, we wil use Fe2O3 as a guide example.
1. Write the name of the first element as the first word

         Fe is Iron

2. Use the subscript of the second element or group of elements as the charge of the first element

naming compounds
3. Look up the Oxidation States of the first element in the periodic table
Iron Element Periodic table
         Iron has two oxidation states, 2 and 3.

4. If there are two or more Oxidation States, write that as a roman number inside a parenthesis

         Therefore, the first word in the name of Fe2O3 is Iron(III).
       
5. Use the subscript of the first element as the charge of the second element or group of elements

        In this case, the subscript of Fe is not shown. That means the subscript is one and oxygen has a charge of -2 or O2-.

Ferric oxide

6. Look up the name of the second element or group of elements in a Table of Anions

       O2- is oxide

7. Write the name of the anion as the second word

        Therefore, Fe2O3 is Iron(III) oxide.

Naming Covalent Compounds

1. Write the name of the first element as the first word
2. Write the name of the root of the second element + ide as the second word
3. Write a Greek prefix according to the subscript of each element
4. The first element does not need the prefix mono

Example:
  • CO2 is Carbon dioxide

Greek Prefixes

Prefix                   Subscript      
mono                       1
di                             2
tri                             3
tetra                         4
pent                         5
hex                          6
hept                         7
oct                          8
non                          9
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