4.1 Acids, bases and neutralisation

• Acids are substances that release H+ ions when they are dissolved in water
• An H+ ion is a proton and an acid is referred to as a proton donor
• Examples of acids = hydrochloric, sulfuric, nitric
• Strong acids fully dissociate when dissolved in water
• Examples of strong acids = hydrochloric, sulfuric, nitric
• Weaks acids partially dissociate when dissolved in water
• Examples of weak acids = ethanoic
• Bases are substances that accept H+ ions and are referred to as proton acceptors
• Different types of bases = metal oxides, metal hydroxides, metal carbonates, alkalis
• Alkalis are bases that dissolve in water releasing OH- ions
• Examples of alkalis = sodium hydroxide, ammonia
• Neutralisation is a reaction between an acid and a base to produce a salt
• Acid + carbonate -> salt + water + carbon dioxide
• Acid + metal oxide -> salt + water
• Acid + alkali -> salt + water
• Ammonia reacts with acids to form ammonium salts containing NH4+
• pH values less than 7 indicate increasing concentrations of H+ ions (acidity).
• The pH scale ranges from 0-14.