Naming Acids
Introduction
- Understanding how to look at the chemical formula for an acid and write a name for it.
- This lecture is an introduction; the next will involve practice problems.
Definition of Acids
- Acid: A compound where one or more H+ ions are bonded to a negative ion.
- Negative Ions: Can be individual elements or polyatomic ions.
- Charges must balance: Positive charge from H+ must equal the negative ion charge.
Importance of Ions in Naming
- The name of an acid is based on the name of the negative ion present in it.
- Separate the acid into H+ and the negative ion parts.
- Identify and name the negative ion to name the acid.
Types of Acids
Acids Without Oxygen
- Example: HCl and HBr.
- Break into H+ and the negative ion (e.g., Cl- is chloride, Br- is bromide).
- Naming Rule: If the negative ion ends in "-ide", take off "-ide" and add between "hydro-" and "-ic" (e.g., hydrochloric acid, hydrobromic acid).
Acids With Oxygen
- Negative Ions: Polyatomic ions ending in "-ate" or "-ite".
"-ate" Ions
- Example: HNO3 (nitrate to nitric acid) and H2CO3 (carbonate to carbonic acid).
- Rule: Remove "-ate" and add "-ic" and "acid".
"-ite" Ions
- Example: HNO2 (nitrite to nitrous acid) and HClO2 (hypochlorite to hypochlorous acid).
- Rule: Remove "-ite" and add "-ous" and "acid".
Special Cases and Exceptions
- Irregular Patterns: Phosphate, phosphite, sulfate, sulfite acids have anomalous names.
- Phosphate to phosphoric acid, phosphite to phosphorus acid.
- Sulfate to sulfuric acid, sulfite to sulfurous acid.
- Hypo/Per Prefixes: Just focus on the ion endings (e.g., permanganate to permanganic acid).
Mnemonic for Naming
- My "ride" has hydraulics: "-ide" to "hydro-" and "-ic"
- I "ate" something icky: "-ate" to "-ic"
- Sprite is delicious: "-ite" to "-ous"
Practice
- Check out practice problems in the following video for reinforcement.
Ensure to memorize polyatomic ion names and endings to accurately name acids. This foundational knowledge is necessary for problem-solving in chemistry.