Some Important Metal Compounds

                            Some Important Metal Compounds

       Sodium-

                          Sodium is 2.27% in the crust. Sodium is always found in the combined state due to high reactivity. The extraction of sodium metal is done by the electrolysis of dissolved sodium hydroxide by the Kastner method or by the electrical decomposition of dissolved by the down method.

       Properties of Sodium-

                          It is a soft soft silver-like white metal that can be cut with a knife.

It is a highly functional metal. That is, it reacts with moist air to make sodium oxide (Na_{2 o} ) and it reacts with water to make sodium hydroxide (NaOH) and hydrogen gas.

It is soluble in Benzene.

It reacts with ammonia to make sodamide ( NaNH₂), and reacts with acid to make corresponding salts hydrogen and alcohol to form sodium alkoxide (NaOH) and hydrogen gas.

      Uses of Sodium-

                        Sodium bicarbonate is uses as a medicine, to remove stomach acidity, to make baking soda, and in fair extinguishers.

When the salt is left in the open air, it absorbs moisture from the air which in transpire.

     1.  Sodium Chloride (NaCl)-Common Salt

                         Sodium chloride is obtained from the evaporation of water from sea or saline likes. Sodium chloride obtained from this salt water evaporation contains impurities of magnesium and potassium. In a saturated solution of this impure salt, pure sodium chloride is obtained by flowing HCl gas. It is Soluble in water.

     Use

  (i.)       It is an essential part of our daily diet.

  (ii.)      Many industrial compounds of importance are obtained from it.

  (iii.)     It forms a coagulation mixture.

  (iv.)     It is used in the preservation of food items like meat, fish, butter etc.

   (v.)     Used to precipitate soap solution.

   2.     Sodium Carbonate (Na₂CO₃)

                        It is a white crystalline soda. The formula for washing soda is Na₂CO₃, 10H2O and anhydrous sodium carbonate is called soda ash. Its aqueous solution is alkaline.

Use

  (i.)       In the industrial production of glass, sodium silicate, paper, borax, hypo, baking powder. 

   (ii.)     In washing clothes.

    (iii.)   In making "melting mixture" The melting mixture is a mixture of sodium carbonate and potassium carbonate.

    (iv.)    In softening of water.