Nomenclature of Acids - Quick Reference

Binary Acids

• Acids: compounds containing hydrogen that release H⁺ in water; aqueous solutions named from the acid's formula.
• Binary acid = hydrogen + one other nonmetal.
• Naming steps for binary acids:
  1. Change the word hydrogen to the prefix hydro-.
  2. Modify the other nonmetal by adding the suffix -ic.
  3. Add the word acid as a second word.
  4. Example: HCl(aq) in water is named hydrochloric acid.
• Phase labels and examples:
  • HF(g) → hydrogen fluoride
  • HF(aq) → hydrofluoric acid
  • HBr(g) → hydrogen bromide
  • HBr(aq) → hydrobromic acid
  • H₂S(g) → hydrogen sulfide
  • H₂S(aq) → hydrosulfuric acid

Oxyacids

• Oxyacids contain hydrogen, oxygen, and at least one other element; built from a polyatomic oxygen-containing anion.
• Naming steps for oxyacids:
  1. Omit hydrogen when naming.
  2. Start with the root name of the anion.
  3. Replace -ate with -ic, or -ite with -ous.
  4. Add the word acid.
• Example: H₂CO₃ (carbonic acid) – hydrogen is omitted, carbonate → carbonate−ate becomes -ic, then add acid.
  • H₂CO₃ → carbonic acid
• There are some exceptions to the general naming method (notably with common inorganic acids):
  • H₂SO₄ is sulfuric acid (not sulfic acid).
  • H₂SO₃ is sulfurous acid (not sulfous acid).

Common Acid Names from Formulas

• Example mappings:
  • ext{HC}2 ext{H}3 ext{O}_2
    ightarrow ext{acetic acid}
  • ext{HClO}_4
    ightarrow ext{perchloric acid}
  • ext{H}2 ext{SO}4
    ightarrow ext{sulfuric acid}
  • ext{H}2 ext{SO}3
    ightarrow ext{sulfurous acid}
• Key rule: naming uses the root of the anion (e.g., acetate → acetic acid; sulfate → sulfuric acid; sulfite → sulfurous acid).