Electrochemistry

Electrolysis of Some Common Electrolytes

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 flow of electrons, and lysis,which means pertaining to.

Electrolysis is the process by which a chemical compound in 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.

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

Therefore, cathode is the electrode which is connected to the negative terminal of battery. It has excess of electrons. Anode is the electrode which is connected to positive terminal of battery. It has deficiency of electrons.

• 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 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 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 state are completely dissociated. Hence, their ions are free to move in any direction.

Examples include aqueous solution of acid and bases.

• Non-electrolyte is the chemical compound which does not conduct electric current in fused state or in aqueous solution and does not undergo any chemical decomposition.

Examples are carbon tetrachloride, alcohol, ether, pure water, etc.

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

When a chemical compound in fused state or in aqueous solution breaks up into electrically charged atoms or group of atoms, the charged particles are called ions. A positively charged ion is cation. They migrate towards cathode. A negatively charged ion is an anion. They migrate towards anode.

Mechanism of el…