MCQ Detailed View

Seawater contains many dissolved minerals, including salts of sodium, magnesium, calcium, and potassium. Among these, magnesium is a metal that can be efficiently extracted from seawater on a large scale. Magnesium is the eighth most abundant element in the Earth's crust and is present in seawater mainly as magnesium chloride (MgCl₂).

The extraction of magnesium from seawater is an important industrial process. The most common method is electrolysis of molten magnesium chloride. First, magnesium chloride is obtained from seawater by reacting it with lime, which separates it from other salts. Then, the molten magnesium chloride is electrolyzed to produce pure magnesium metal. This method is preferred because magnesium is highly reactive and cannot be easily extracted by direct reduction with carbon.

Magnesium is a lightweight, silvery-white metal with many industrial uses. It is used in the production of aluminum alloys, which are applied in aerospace, automotive, and electronics industries. Magnesium is also important in the chemical industry for preparing compounds like magnesium oxide (MgO) and magnesium hydroxide (Mg(OH)₂).

Other metals listed in the options are not typically extracted from seawater. Potassium is obtained from potash and other mineral deposits, while aluminum is extracted from bauxite ore, not seawater.

Understanding magnesium extraction is an essential part of chemistry, particularly in inorganic chemistry, metallurgy, and industrial chemistry. Knowledge of how metals are obtained from natural sources like seawater helps students understand the practical applications of chemistry in daily life and industry.

Therefore, the correct answer is Magnesium, which is efficiently extracted from seawater and widely used in industry.