Definition Of Electrolyte

Definition Of Electrolyte

An electrolyte is a chemical compound that, in solution or in the molten state, dissociates into ions and conducts an electric current. On passing an electric current from an external source.

More About Electrolyte

• The ions in the electrolyte migrate towards the oppositely charged electrodes. Positive ions (Cations) migrate to the negative electrode (Cathode) and negative ions (Anions) to the positive electrode (Anode) and they discharge at respective electrodes
• This phenomenon is called electrolysis and the container in which electrolysis occur is called electrolytic cell
• Aqueous solution of Copper sulphate as Electrolyte: An aqueous solution of copper sulphate an electrolyte; a strip of pure copper metal as cathode; and a strip of impure copper as an anode.
• When an electric current is passed through the aqueous solution of copper sulphate, copper ions (Cu2+) migrate towards the pure copper strip cathode, get discharge and deposit over it
• Sulphate ( SO4-2 ) ions move towards the impure copper anode, dissolve its Copper into the solution as copper ions and thus keep their concentration constant in the solution
• Molten Sodium chloride as Electrolyte: When Molten Sodium chloride is subjected to electrolysis .Sodium ions migrate towards Cathode and Chloride ions migrate towards Anode. At Cathode Sodium ions reduced to sodium metal ,whereas chloride ions are oxidized to chlorine gas at anode electrode.
• Based on dissociation ability electrolytes are classified into two types:
  • 1. Strong Electrolytes Ex: Aqueous sodium hydroxide
    2. Weak Electrolytes Ex:Ammonium hydroxide

Examples of Electrolyte:

1. Strong Electrolytes

A. Strong Acids

• - Hydrochloric acid
  - Hydro bromic acid
  - Hydro iodic acid
  - Nitric acid
  - Chloric acid
  - Perchloric acid
  - Sulphuric acid


 

B. Strong Bases:

• - Sodium hydroxide
  - Potassium hydroxide
  - Lithium hydroxide
  - Barium hydroxide
  - Calcium hydroxide


 

C. Salts:

• - Sodium chloride
  - Potassium chloride
  - Potassium bromide
  - Magnesium chloride


 

2. Weak Electrolytes:

a. Weak acids:

• - Hydrofluoric acid - Acetic acid - Carbonic acid - Phosphoric acid

b. Weak Bases:

• - Ammonium hydroxide
  - Pyridine

Solved Example:

Ques: To which of the following electrolytes dissociation constant is high?

• A. Aqueous sodium chloride
  B. Carbonic acid
  C. Ammonium hydroxide
  D. Acetic acid

Answer: A - Aqueous sodium chloride is a strong electrolyte, hence its dissociation constant is high when compared with other electrolytes (Ammonium hydroxide, Carbonic acid and Acetic acid)

Ques: Sulphuric acid is a ____

• A. Strong acid and Weak electrolyte
  B. Weak acid and strong electrolyte
  C. Strong acid and strong electrolyte
  D. Weak acid and weak electrolyte

Answer - C