1. Naming and Writing Formulas for Acids and Bases
Chapter 9
Chemical Names and Formulas
Section 4

2. Vocabulary
Acid
A compound that produces hydrogen ions (H+) in solution.
Base
A compound that produces hydroxide ions (OH-) in solution.

3. State Standards
4.6
Name and write the chemical formula for simple ionic and molecular compounds, including those that contain the polyatomic ions: ammonium, carbonate, hydroxide, nitrate, phosphate, and sulfate

4. Key Questions How do you determine the name and formula of an acid?
How do you determine the name and formula of a base?

5. Names and Formulas of Acids
You can consider the acid to consist of an anion combined with as many hydrogen ions as needed to make the molecule electrically neutral.
The chemical formulas of acids are in the general form HnX.

6. Three Rules for Naming Acids
When the name of the anion ends in –ide, the acid name begins with the prefix hydro-. The stem of the anion has the suffix –ic and is followed by the word acid.
HCl (X is chloride) is hydrochloric acid.
When the anion names ends in –ite, the acid name is the stem of the anion with the suffix –ous, followed by the word acid.
H2SO3 (X is sulfite) is named sulfurous acid

7. Three Rules for Naming Acids
When the anion name ends in –ate, the acid name is the stem of the anion with the suffix -ic, followed by the word acid.
HNO3 (X is nitrate) is named nitric acid.

8. Writing Formula for Acids
To write the formula for an acid, use the rule for writing the name of the acid in reverse. Then balance the ionic charges just as you would for any ionic compound.

9. Name and Formula of Bases
A base is generally an ionic compound that produces hydroxide (OH-) when dissolved in water.
Bases are named in the same way as other ionic compounds- the name of the cation is followed by the name of the anion.
NaOH
Sodium Hydroxide

10. Name and Formula of Bases
To write the formula for a base, first write the symbol for the metal cation followed by the formula for the hydroxide ion. Then, balance the ionic charges just as you would for any ionic compound.
Aluminum hydroxide
Al3+
OH-
Al(OH)3

11. Summary
If the anion name ends in –ide, the acid name begins with the prefix hydro-. The stem of the anion has the suffix –ic and is followed by the word acid. If the anion name ends in –ite, the acid name is the stem of the anion with the suffic –ous, followed by the word acid. If the anion name ends in –ate, the acid name is the stem of the anion with the suffix –ic, followed by the word acid. To write the formula for an acid, use the rule for writing the name of the acid in reverse.

12. Summary
Bases are named like other ionic compounds. To write the formula for a base, write the symbol for the metal cation followed by that of the hydroxide ion. Then, balance the ionic charges.