ACID and BASE

ARRHENIUS CONCEPT :::

  • ACID : Acid are those species which give H+ ions when dissolved in water.
   
    

When HCl dissolves in water it dissociates to give H+ and CL- ions.

 
                         
  • BASE : Base are those species which give OH- ions when dissolved in water.
     
    

When NaOH dissolves in water it dissociates to give Na+ and OH-

 BRONSTED LOWERY CONCEPT :::

• ACID : Acid are those species which donates H+ ions. i.e H+ ion donors are called acid.

• BASE : Base are those species which accepts H+ ions. i.e H+ ion acceptor are called base.

Here Acetic Acid ( CH3COOH ) donates H+ ion and hence acts as acid while Water (H2O) accepts H+ ion and thereby acts as base.

LEWIS CONCEPT :::

• ACID : Acid are those species which accepts lone pair of electrons.

• BASE : Base are those species which donates lone pair of electrons.

Here Ammonia ( NH3) donates lone pair of electrons and hence acts as Lewis Base while Boron Fluoride (BF3) accepts lone pair of electrons and hence acts as Lewis acid.