ANS:A - freeze drying

Common salt is generally not produced commonly by electrolytic method from brine. Common salt is generally not produced commonly by the electrolytic method from brine because:

Electrolytic Method Overview:

1. Process: The electrolytic method involves passing an electric current through brine (a concentrated solution of sodium chloride), leading to the electrolysis of sodium chloride into its components.
2. Products: This method produces sodium hydroxide (NaOH), chlorine gas (Cl₂), and hydrogen gas (H₂) as the primary products, rather than just sodium chloride (common salt).

Reasons for Not Using Electrolysis for Common Salt Production:

1. Complexity and Cost: The electrolytic process is more complex and expensive compared to other methods, making it less viable for the straightforward production of common salt.
2. Desired Product: The main goal of producing common salt is to obtain pure sodium chloride, whereas electrolysis yields additional products that may not be desirable for salt production.
3. Alternative Methods: More efficient and cost-effective methods for producing common salt include:
   • Solar Evaporation: Utilizing sunlight to evaporate water from seawater or brine, leaving behind crystallized salt.
   • Vacuum Evaporation: Evaporating water under reduced pressure to obtain salt crystals.

Summary:

The electrolytic method is not commonly used for producing common salt from brine due to its complexity, higher costs, and the focus on producing sodium hydroxide and chlorine rather than just sodium chloride. More straightforward methods like solar and vacuum evaporation are preferred for salt production.