Naming Compounds

Hannah Ambinder & Lauren Stone
Naming Compounds
-Ionic compounds are made up of metals and nonmetals, which form cations and anions.
Together, their net charge must equal zero.
The metal goes first, and the ending “-ide” gets added to the nonmetal. Example: NaCl is
written as sodium chloride.
If the compound contains a polyatomic ion, do not change anything. Example: LiNO3 is
written as lithium nitrate.
Use roman numerals to indicate the number of valence electrons in transition metals.
Example: Fe(OH)2 is written as iron (II) hydroxide. Aluminum (III), Zinc (II), and Silver (I)
are all exceptions to this rule.
If there is a hydrate in a compound, you must use number prefixes. Follow the format of
compound · prefix-hydrate. Example: CuSO4 · 5H2O is copper (II) sulfate pentahydrate.
-Covalent compounds are formed from multiple nonmetals, and include acids, bases, and
organic compounds.
Name the element furthest left or closest to the bottom of the period table first. Use
number prefixes on both words, but do not write “mono” on the first word. Drop double
vowels. Example: CO2 is written as carbon dioxide.
Acid is a substance that yields H+ ions when dissolved in water. If there is a hydrogen ion
at the front of the formula, you should name it as an acid. There are two types of acids.
o Binary acids are composed of two elements, usually hydrogen and a halogen. To
name them, use the format hydro-element name-ic acid. Example: HCl is written
as hydrochloric acid.
o Oxyacids are formed from hydrogen, oxygen, and a third element. To name one,
you must know the name of the polyatomic ion that it contains. If the polyatomic
ends with “–ate,” change the ending to “–ic.” HNO3 is written as nitric acid. If the
polyatomic ends with “–ite,” change the ending to “–ous.” H2SO3 is written as
sulfurous acid.
o If a covalent compound contains OH-, name it as a base. Do not use number
prefixes to name bases. Example: NaOH is written simply as sodium hydroxide.
Hannah Ambinder & Lauren Stone
Mixed Practice Problems
1. CuCO3
2. CCl4
3. Li2O
4. HBr
5. LiClO4 · 3H2O
6. H2SO3
7. Sc2(SO4)3
8. HClO
9. MgSO4
10. Al2O3
11. NH4OH
12. PCl5
13. Ba3(PO4)2
14. MgI2
15. LiOH
16. HF
17. AgCH3COO
18. N2O3
19. NiSO4 · 6H2O
20. HC2H3O2
Hannah Ambinder & Lauren Stone
Answer Key
1. Copper (II) carbonate
2. Carbon tetrachloride
3. Lithium oxide
4. Hydrobromic acid
5. Lithium perchlorate trihydrate
6. Sulfurous acid
7. Scandium (III) sulfate
8. Hypochlorous acid
9. Magnesium sulfate
10. Aluminum oxide
11. Ammonium hydroxide
12. Phosphorous pentachloride
13. Barium phosphate
14. Magnesium iodide
15. Lithium hydroxide
16. Hydrofluoric acid
17. Silver acetate
18. Dinitrogen trioxide
19. Nickel (II) sulfate hexahydrate
20. Acetic acid