Types and Chemical Properties of Acids

Types of Acids

  • Acids can be classified as Organic Acids and Mineral Acids
  • The acids present in plant materials and animals are called organic acids
  • Example Acetic acid (or Ethanoic acid), Citric acid, Lactic acid, Tartaric acid, Oxalic acid and Formic acid (or Methanoic acid).
  • The acids prepared from the minerals of the earth are called mineral acids. Mineral acids are man made acids.
  • Hydrochloric acid, Sulphuric acid and Nitric acid. Concentrated mineral acids are very dangerous.
  • Question :Why the dilution of a concentrated acid should always be done by adding concentrated acid to water gradually with stirring and not by adding water to concentrated acid.
  • Answer When a concentrated acid is added to water for preparing a dilute acid, then the heat is evolved gradually, and easily absorbed by the large amount of water (to which acid is being added).
  •  If, however, water is added to concentrated acid to dilute it, then a large amount of heat is evolved at once.
  • This heat changes some of the water to steam explosively which can splash the acid on our face or clothes and cause acid burns and can even break the glass.

Chemical Properties of Acid and Base

  • Acid + Metal → Salt + Hydrogen gas
  • Zn (s) + H2SO4 (aq) – ZnSO4 (aq) + H2 (g
experiment between sulphuric acid and zinc results in evolution of hydrogen gas by bubble test
experiment between sulphuric acid and zinc results in evolution of hydrogen gas by bubble test
  • Only hydrogen gas burns making a ‘pop’ sound.
  • This shows that hydrogen gas is evolved in the reaction of dilute sulphuric acid with zinc metal (taken in the form of zinc granules).
  • Acids react with metal carbonates (and metal hydrogencarbonates) to form carbon dioxide gas
  • Metal carbonate + Acid — Salt + Carbon dioxide + Water
  • Metal hydrogen carbonate + Acid — Salt + Carbon dioxide + Water
  • When dilute hydrochloric acid reacts with sodium carbonate, then sodium chloride, carbon dioxide and water are formed
chemical reaction between sodium carbonate with hydrochloride acid to form sodium chloride and carbon dioxide and water.
chemical reaction between sodium carbonate with hydrochloride acid to form sodium chloride and carbon dioxide and water.
  • The carbon dioxide gas is formed in the form of brisk effervescence (the rapid escape of small bubbles of gas from the liquid).
  • When dilute hydrochloric acid reacts with sodium hydrogen carbonate, then sodium chloride, carbon dioxide and water are formed

  • On passing the carbon dioxide gas evolved through lime water
conversion of lime water into white precipitate of calcium carbonate by passes of carbon dioxide gas
conversion of lime water into white precipitate of calcium carbonate by passes of carbon dioxide gas
  • Calcium carbonate (White ppt.) Makes Lime Water Milky 
  • On passing excess Carbon Dioxide white precipitate formed first dissolves due to the formation of a soluble salt calcium hydrogencarbonate, and the solution becomes clear again
conversion of white precipitate of calcium carbonate into clear solution of calcium hydrogen carbonate
conversion of white precipitate of calcium carbonate into clear solution of calcium hydrogen carbonate
  • limestone, marble and chalk are the different forms of the same chemical compound ‘calcium carbonate’. Even the egg-shells are made of calcium carbonate.
some compound made up of calcium carbonate
  • Acids react with bases (or alkalis) to form salt and water
  • the reaction between an acid and a base to form salt and water is called a neutralisation reaction
  • Base + Acid → Salt + Water
neutralization reaction between base sodium hydroxide and acid hydrochloride acid to form salt sodium chloride and water.
neutralization reaction between base sodium hydroxide and acid hydrochloride acid to form salt sodium chloride and water.

Reaction of Metallic Oxides with Acids

  • Metal oxide + Acid → Salt + Water
chemical reaction between copper oxide and hydrochloride acid to form copper chloride and water
chemical reaction between copper oxide and hydrochloride acid to form copper chloride and water
  • metallic oxides are said to be basic oxides and are basic in nature
  • Nonmetallic oxides are acidic in nature.
Scroll to Top

Sign in to edusaint

Login with your Social Account