Properties of acids and bases

Properties of acids and bases

Physical Properties of Acids

  • Acids have a sour taste traditionally associated with vinegar and citrus fruits.
  • In aqueous solutions, they are conductors of electricity due to the ions present.
  • Acids have a pH less than 7, with their strength determined by how completely they ionise in water.
  • They may be liquid, as with hydrochloric or nitric acid, or solid, as with citric and ascorbic acids.

Physical Properties of Bases

  • Bases are characterised by a bitter taste and are often seen in foods like cocoa and coffee.
  • They feel slippery to the touch, a common example being soap which is a weak alkaline solution.
  • Bases have a pH greater than 7, with their strength determined by how completely they ionise in water.
  • They are also conductive in aqueous solution due to the presence of ions.

Chemical Properties of Acids

  • Acids react with bases in a reaction known as neutralisation, producing a salt and water.
  • They react with metals to produce hydrogen gas and salt. For example, hydrochloric acid reacts with zinc to form zinc chloride and hydrogen gas.
  • Acids also undergo decomposition reactions when heated, breaking down into simpler substances.

Chemical Properties of Bases

  • Bases also react in neutralisation reactions with acids, resulting in water and a salt.
  • Bases react with fats, in a type of reaction called saponification, to produce soap.
  • Bases like sodium hydroxide are also known for their ability to dissolve some metals, producing hydrogen gas.