54) How is sodium chloride extracted from sea water

Sodium chloride

• Sodium chloride is an ionic salt and is represented by the chemical formula $\mathrm{NaCl}$.
• It is an essential compound for our body as it maintains blood pressure, contracts and relaxes muscles, and maintain the osmotic fluid balance.

Stepwise process of Extraction

• Evaporation of seawater - First the seawater is evaporated which leads to the formation of crude salt. The crude salt contains sodium chloride (salt) and sand and clay particles.
• Treatment of crude salt with water - The crude salt-containing (salt + sand and clay particles) is treated with water and then the evaporation process is again done which leads to the formation of rock salt ($\mathrm{NaCl}$). If we want to use rock salt for consumption, then we iodize it to sodium iodide $\left(\mathrm{NaI}\right)$. Thus common salt ( sodium chloride + sodium iodide + potassium iodide) is formed.