• Common salt
  • Neutral salt
  • Basic salt
  • Acidic salt
  • Baking soda
  • Washing soda

Definition of Salts

Salt is a mineral substance composed primarily of sodium chloride (NaCl), a chemical compound belonging to the larger class of ionic salts

More About Salts

  • Salts of a strong acid and a strong base are neutral with pH value of 7
  • Salts of a strong acid and weak base are acidic with pH value less than 7 and those of a strong base and weak acid are basic in nature, with pH value more than 7
  • The salt formed by the combination of hydrochloric acid and sodium hydroxide solution is called sodium chloride. This is the salt which we use in food. Its pH value is 7. It is a neutral salt
  • Seawater contains many salts dissolved in it. Sodium chloride is separated from these salts. Beds of rock salt were formed when seas of bygone ages dried up. These large crystals of salt are brown due to impurities
  • The common salt thus obtained is an important raw material for various materials of daily use, such as sodium hydroxide, baking soda, washing soda, bleaching powder and many more
  • When electricity is passed through an aqueous solution of sodium chloride (called brine), it decomposes to form sodium hydroxide : 2NaCl (aq) + H2O (l) – 2NaOH (aq) + H2 (g) + Cl2 (g)
  • Chlorine gas is given off at the anode, and hydrogen gas at the cathode. Sodium hydroxide solution is formed near the cathode. The three products produced in this process are all useful
  • Bleaching powder is produced by the action of chlorine on dry slaked lime[Ca(OH)2]
  • Ca(OH)2 + Cl2 – CaOCl2 + H2O CaOCl2 The soda commonly used in the kitchen for making tasty cakes and other snacks is baking soda. It is produced using sodium chloride as one of raw materials
    NaCl + H2O + CO2 → NaHCO3 + NH4Cl
    The chemical name of baking soda is sodium hydrogen carbonate . It is a mild non-corrosive base. When baking soda is heated, following reaction takes place
    2NaHCO3→ Na2CO3 +H2O + CO2
    Another chemical that can be obtained from sodium chloride is Na2 CO3 .10H2O.
    Sodium carbonate is obtained by heating baking soda. Recrystallization of sodium carbonate gives washing soda
    Na2CO3 + 10H2O → Na2CO3.10H2O

Uses of salts:

    Bleaching powder is used for bleaching cotton and linen in the textile industry, for bleaching wood pulp in paper factories and for bleaching washed clothes in laundry, as an oxidising agent in many chemical industries; and for disinfecting drinking water to make it free of germs

    Baking soda is used for making baking powder, which is a mixture of baking soda (sodium hydrogencarbonate) and a mild edible acid such as tartaric acid. When baking powder is heated or mixed in water, the following reaction takes place
    NaHCO3 + H+ CO2+H2O + Sodiumsalt
    Carbon dioxide produced during the reaction causes bread or cake to rise making them soft and spongy
    Sodium hydrogencarbonate is also an ingredient in antacids. Being alkaline, it neutralizes excess acid in the stomach and provides relief
    Sodium carbonate (washing soda) is used in glass, soap and paper industries
    It is used in the manufacture of sodium compounds such as borax and for removing permanent hardness of water
    Sodium carbonate can be used as a cleaning agent for domestic purposes.