Naming Binary Covalent Compounds
Remember Covalent Compounds are between 2 NON-METALS!
Rule 1. The element with the lower group number is written first in the name. (The
number on the left of the periodic table is listed first.)
Exception: If there are ONLY carbons and hydrogens, or nitrogen and hydrogens, the
carbons will get listed first.
Ex: CH4, C2H6, NH3, N2H6
Rule 2. The second element in the name is named by adding the suffix -ide to the root
name of the element.
Rule 3. Greek prefixes are used to indicate the number of atoms of each nonmetal element
in the chemical formula for the compound.
HINT: You will ALWAYS use a greek prefix. The only exception is if the first element
listed is a mono. Then the first element does not use a prefix.
Note: when the addition of the Greek prefix places two vowels adjacent to one another, the "a" (or the "o") at the end of
the Greek prefix is usually dropped; e.g., "nonaoxide" would be written as "nonoxide", and "monooxide" would be written
as "monoxide". The "i" at the end of the prefixes "di-" and "tri-" are never dropped.
Prefixes
1
mono2
di3
tri4
tetra5
penta-
6
7
8
9
10
hexaheptaoctanonadeca-
Examples:
1. S2Cl4 = Disulfur tetrachloride
2. CH4 = Carbon tetrahydride
3. nitrogen monoxide = NO
4. diphosphorous pentoxide = P2O5
Chemistry: Covalent Binary Compounds: Nonmetal–Nonmetal Combinations
Write the name of each of the following compounds.
1. HF
1. ______________________________________
2. H2S
2. ______________________________________
3. NO
3. ______________________________________
4. N2O
4. ______________________________________
5. NO2
5. ______________________________________
6. N2O5
6. ______________________________________
7. SO2
7. ______________________________________
8. CBr4
8. ______________________________________
9. C2H6
9. ______________________________________
10. C4H10
10. ____________________________________
Write the chemical formula for each of the given names.
11. nitrogen triiodide
11. ___________________________________
12. dinitrogen tetroxide
12. ___________________________________
13. sulfur trioxide
13. ___________________________________
14. carbon monoxide
14. ___________________________________
15. dihydrogen monoxide
15. ___________________________________
16. hydrogen monobromide
16. ___________________________________
17. phosphorus trichloride
17. ___________________________________
18. tricarbon octahydride
18. ___________________________________
19. carbon tetrahydride
19. ___________________________________
20. dicarbon tetrahydride
20. ___________________________________