When naming covalent compounds, prefixes must be used to identify the number of atoms. The prefixes are as follows.
1: Mono-
2: Di-
3: Tri-
4: Tetra-
5: Penta-
6: Hexa-
7: Hepta-
8: Octa-
9: Nona-
10: Deca-
To begin naming, identify the number of atoms of the first element in the compound. Find the corresponding prefix and add it to the element taken directly from the periodic table. An exception to the beginning step is if the prefix is mono-, it will not be added onto the element.
Next, identify the number of atoms of the second element and find the corresponding prefix. Even if the prefix is mono-, add it to the element. Additionally remove the ending and add the suffix -ide.
Name CBr4.
We see that there is only one carbon atom which would give the prefix mono-. Since carbon is the first element we do not add it onto the name. There are 4 bromine atoms which gives the prefix tetra-. We remove the ending of bromine and add the suffix -ide and combine the two to get tetrabromide. The name of this compound is “carbon tetrabromide”.
Name CO.
As in the example above there is only one carbon. However, the oxygen has one atom as well giving a prefix of mono-. Since oxygen is the second atom we name the compound “carbon monoxide”.
This article was written for you by Jeremie, one of the tutors with SchoolTutoring Academy.