Notes On Alkali Metals: Anomalous Properties And Compounds - CBSE Class 11 Chemistry
Lithium exhibits some anomalous behaviour and it exhibits a “diagonal relationship” with magnesium.



Lithium and magnesium have some notable similarities in their chemical properties. 
  • Both form nitrides
  • Both react slowly with water
  • Neither element forms compounds containing the superoxide ion
  • Both the metals form water-soluble chlorides that are found as hydrates. 

Important compounds of Sodium:  Sodium carbonate, Sodium chloride, Sodium hydroxide and sodium hydrogen carbonate.

Sodium carbonate or washing soda (Na2CO3) can be formed by Solvay process. It is typically found as a hydrate with ten water molecules of crystallisation called sodium carbonate decahydrate.

It is used in water softening, as well as in laundry and cleaning. 
It is used in the manufacture of glass and in the production of soap, borax and caustic soda.
Sodium carbonate is also necessary in the paint, paper and textile industries.

Sodium chloride (NaCl) can be isolated from sea water.Sodium chloride is commonly used as table salt and in the preparation of other compounds that contain sodium such as sodium hydroxide, sodium carbonate and sodium peroxide.

Sodium hydroxide (NaOH) can be prepared by the electrolysis of sea water in the Castner-Kellner cell.

  • In its pure form it is a white solid.
  • It is very caustic.
  • It has melting point of 591K.
  • It is deliquescent.  It means that samples of sodium hydroxide left in the open will absorb water from the air and dissolve.

Baking soda (or) sodium hydrogen carbonate (NaHCO3) can be produced by reacting sodium carbonate with carbon dioxide.It is used as a mild skin antiseptic, as a household cleaner, as an ingredient in mouthwash and toothpaste and as treatment for indigestion due to acidity. It is also used in certain types of fire extinguishers.

Sodium ions play important roles in transmitting nerve signals, regulating water transport into cells, and transporting nutrients into cells.

Potassium ions are essential for activating enzymes, the metabolism of ATP in cells, and transmitting nerve signals. The sodium-potassium pump a transmembrane protein in cell membranes uses active transport to move sodium and potassium ions across cell membranes against the concentration gradients.  

Summary

Lithium exhibits some anomalous behaviour and it exhibits a “diagonal relationship” with magnesium.



Lithium and magnesium have some notable similarities in their chemical properties. 
  • Both form nitrides
  • Both react slowly with water
  • Neither element forms compounds containing the superoxide ion
  • Both the metals form water-soluble chlorides that are found as hydrates. 

Important compounds of Sodium:  Sodium carbonate, Sodium chloride, Sodium hydroxide and sodium hydrogen carbonate.

Sodium carbonate or washing soda (Na2CO3) can be formed by Solvay process. It is typically found as a hydrate with ten water molecules of crystallisation called sodium carbonate decahydrate.

It is used in water softening, as well as in laundry and cleaning. 
It is used in the manufacture of glass and in the production of soap, borax and caustic soda.
Sodium carbonate is also necessary in the paint, paper and textile industries.

Sodium chloride (NaCl) can be isolated from sea water.Sodium chloride is commonly used as table salt and in the preparation of other compounds that contain sodium such as sodium hydroxide, sodium carbonate and sodium peroxide.

Sodium hydroxide (NaOH) can be prepared by the electrolysis of sea water in the Castner-Kellner cell.

  • In its pure form it is a white solid.
  • It is very caustic.
  • It has melting point of 591K.
  • It is deliquescent.  It means that samples of sodium hydroxide left in the open will absorb water from the air and dissolve.

Baking soda (or) sodium hydrogen carbonate (NaHCO3) can be produced by reacting sodium carbonate with carbon dioxide.It is used as a mild skin antiseptic, as a household cleaner, as an ingredient in mouthwash and toothpaste and as treatment for indigestion due to acidity. It is also used in certain types of fire extinguishers.

Sodium ions play important roles in transmitting nerve signals, regulating water transport into cells, and transporting nutrients into cells.

Potassium ions are essential for activating enzymes, the metabolism of ATP in cells, and transmitting nerve signals. The sodium-potassium pump a transmembrane protein in cell membranes uses active transport to move sodium and potassium ions across cell membranes against the concentration gradients.  

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