Overview
This lecture explains how to name acids in chemistry, distinguishing between acids with and without oxygen, and provides naming patterns and key examples.
Types of Acids
- Acids always begin with hydrogen (H) in their formula.
- There are two types: acids without oxygen and acids with oxygen.
Naming Acids Without Oxygen
- Use the prefix "hydro-" to indicate no oxygen present.
- Naming pattern: "hydro" + root of element + "ic acid."
- Example: HCl is hydrochloric acid; HI is hydroiodic acid; HF is hydrofluoric acid.
- "Hydro" signals no oxygen; "ic acid" is the naming ending.
Naming Acids With Oxygen
- No prefix is used if oxygen is present.
- The root comes from the polyatomic ion.
- If the ion ends with "-ite," change to "-ous acid" (e.g., NO₂⁻ is nitrite → HNO₂ is nitrous acid).
- If the ion ends with "-ate," change to "-ic acid" (e.g., NO₃⁻ is nitrate → HNO₃ is nitric acid).
- For phosphite (PO₃³⁻), the acid is called phosphorous acid (H₃PO₃); phosphate (PO₄³⁻) becomes phosphoric acid (H₃PO₄).
- Some acid names (e.g., phosphorous, phosphoric) include an extra "r" by convention.
Naming Mnemonics and Tips
- "I ATE organIC apples despITE being poisonOUS" — "ate" ions become "ic" acids, "ite" ions become "ous" acids.
- Always balance charges when writing acid formulas.
Key Terms & Definitions
- Acid — A compound starting with H, producing H⁺ ions in solution.
- Hydro- prefix — Indicates an acid without oxygen.
- Polyatomic ion — An ion made of multiple atoms (e.g., NO₃⁻, PO₄³⁻).
- "-ic acid" — Ending for acids from "-ate" ions.
- "-ous acid" — Ending for acids from "-ite" ions.
Action Items / Next Steps
- Practice acid naming problems provided in the description box.
- Review polyatomic ions and their charges.
- Sign up for live tutoring for more detailed explanations.