Neutralisation and salts · Year 11
Acids react with bases, alkalis, carbonates and reactive metals to make salts. In neutralisation, hydrogen ions from the acid and hydroxide ions from the alkali join to make water. A salt’s name comes from the metal and the acid: hydrochloric acid makes chlorides, sulfuric acid makes sulfates and nitric acid makes nitrates.
Key facts
- acid + base → salt + water. Bases are metal oxides and hydroxides; alkalis are bases that dissolve in water.
- acid + metal → salt + hydrogen, and acid + carbonate → salt + water + carbon dioxide.
- Hydrochloric acid makes chlorides, sulfuric acid makes sulfates and nitric acid makes nitrates.
- The ionic equation for neutralisation is H⁺(aq) + OH⁻(aq) → H2O(l).
- To make a soluble salt, add an insoluble base or carbonate to the acid until it is in excess, filter, then crystallise. With an alkali, use a titration to find the exact amounts.
- Insoluble salts are made by mixing two solutions to form a precipitate, which is filtered, washed and dried.