Electrolysis

Electrolysis

Introduction

• Electrochemistry is the branch of chemistry which deals with interconversion of chemical and electrical energy.
• Chemical energy is converted to electrical energy due to the chemical reaction in dry cell. Electrochemistry is useful to design and operate such cells.
• The current research focusses on designing fuel cells as compact source of electricity.

An ionic compound or electrovalent compound is formed when metallic atoms donate electrons and non-metallic ions accept electrons.

The word electrolysis is made up of two words electro, which means the flow of electrons, and lysis, which means pertaining to.

Electrolysis is the process by which a chemical compound in the fused state or in aqueous solution undergoes a chemical change on the passage of current.

During electrolysis, a chemical change is brought about by electric energy.

• Electrolytic cell or voltameter is the vessel consisting of glass, containing two electrodes and an electrolyte.

 

• The graphite or metal rods through which electric current enters or leaves from an electrolyte are called electrodes.

Therefore, a cathode is the electrode which is connected to the negative terminal of the battery. It has an excess of electrons. An anode is than electrode which is connected to positive terminal of battery. It has deficiency of electrons.

 

Difference between cathode and anode 

Anode	Cathode
Connected to positive terminal of the battery	Connected to negative terminal of the battery
Migration of anion occurs	Migration of cations occurs
Oxidation occurs	Reduction occurs

Differences between metallic and electrolytic conductors

Metallic Conductors	Electrolytic Conductors
Flow electrons from negative pole to positive pole is responsible for conduction.	Flow of ions in solution to the respective electrodes is responsible for conduction.
Shown by metals and alloys	Shown by aqueous solution of ionic compounds
Present in both solid and liquid state of metals	Present in molten or aqueous solution of the ionic compounds
Physical process	Chemical process

• Electrolyte refers to the compound, which in fused state or in aqueous state conducts electric current so that chemical decomposition of the compound takes place.

The electrolytes which allow a large amount of current to flow through them are called strong electrolytes. The strong electrolytes in fused state are completely dissociated and hence, their ions are free to move in any direction.

Examples include an aqueous solution of mineral acid and caustic alkalis.

The electrolytes which allow a very small amount of current to flow through them are called weak electrolytes. The strong electrolytes in fused stat…