Formulas of Acids An acid is a substance that when dissolved in water, dissociates or breaks apart into a hydrogen ion (H + ) and an anion. Acids always have hydrogen as the first element in the formula, HCl (aq), HNO 3 (aq), H 2 SO 4 (aq), etc.
Naming Binary Acids Binary acids contain only two elements, hydrogen and a monatomic anion whose name ends in the suffix -ide. To name a binary acid like HCl –Begin the name with the prefix hydro- –Next use the root of the second elements name, e.g. chlor –Replace the suffix of the anion with the suffix -ic –Add the word acid HCl is hydrochloric acid
Examples HF H 2 S HBr H 2 O Hydroiodic acid Hydronitric acid Hydroselenic acid
Ternary Acids Ternary acids contain three elements, with hydrogen being the first element in the formula and oxygen being the last. To name a ternary acid such as H 2 SO 4 –Remove the hydrogen ion(s) and determine the formula of the anion –Replace the suffix -ate becomes -ic acid -ite becomes -ous acid H 2 SO 4 anion SO 4 2- sulfuric acid
Polyatomic Ions Have you memorized the polyatomic ions yet? NH 4 + ammonium PO 4 3- phosphate CO 3 2- carbonate SO 4 2- sulfate ClO - hypochlorite SO 3 2- sulfite ClO 2 - chlorite CN - cynaide ClO 3 - chlorate NO 3 - nitrate ClO 4 - perchlorate NO 2 - nitrite OH - hydroxide C2H3O2-C2H3O2- acetate
Examples HClO 4 H 3 PO 4 HNO 3 HNO 2 Acetic acid Hypochlorous acid Carbonic acid
Summary Binary Acids Hydro ___ic acid Ternary Acids If the anion is -ate it becomes _____ic acid If the anion is -ite it becomes _____ous acid