THE MOLE AND THE AVOGADRO’S CONSTANT, MOLE ATOM, Mathematically,

 

THE MOLE AND THE AVOGADRO’S CONSTANT:

            One mole of a substance contains fixed number of particles 6.02x10²³ mole^-1. This constant number is also known as Avogadro’s constant and it is represented by ‘L’ Particles of substance may be atoms, molecules, ion or even electrons.

 

MOLE ATOM:

            In case of an element one mole is referred to 6.02x10²³ atoms, this why it is also called one mole atom. Practically it is equal to gram relative atomic mass of that element i.e;  relative atomic mass expressed in grams. e.g;

 

            1 mole atom of nitrogen = 14g.

            1 mole atom of hydrogen = 1g.

            1 mole atom oxygen = 16g.

            1 mole atom of chlorine = 35.5g.

            1 mole atom of iron = 56g.

            1 mole atom of sodium = 23g.

            Mathematically,

 

  Mass in grams

Mole atom =                                      

Ar of the element

 

                                    N =

 

MOLE MOLECULE:

            In the case of covalent compounds one mole is referred to 6.02x10²³ molecules. This is why it is also called mole molecule. Practically it is gram relative molecular mass i.e.; relative molecular mass expressed in grams. For example,

 

            1 mole molecular of water = 18g.

            1 mole molecule of CO₂ = 44g.

            1 mole molecule of H₂SO₄ = 98g.

            1 mole molecule of hydrogen = 2g.

            1 mole molecule of oxygen = 16g.

 

Mathematically,

Mass in grams

Mole molecule =                                           

Mr of the molecule

 

                                    n =