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Iodine is a chemical element with the symbol I and atomic number 53. It is a non-metallic halogen that is found mainly in seawater and rocks. It is an essential nutrient that is required by the thyroid gland to produce hormones that regulate metabolism. Iodine is also used in various industrial and pharmaceutical applications. In this article, we will discuss the three methods of preparation of iodine.
1. From Seaweed
Historically, the primary source of iodine was seaweed. Seaweed contains high levels of iodine, which it absorbs from seawater. The process of extracting iodine from seaweed involves burning the seaweed and collecting the ashes. The ashes are then leached with water to dissolve the iodine. The solution is then evaporated to obtain solid iodine crystals.
2. From Iodides
Iodine can also be prepared from iodides such as potassium iodide, sodium iodide, or calcium iodide, among others. The process involves oxidizing the iodide with an oxidizing agent such as chlorine or hydrogen peroxide. The iodine is then separated from the solution by filtration, and the solid iodine crystals are obtained by evaporation.
3. From Brine
Another method of preparing iodine is by the extraction of iodine from brine. Brine is a solution of salt and water that is found in salt mines and salt lakes. It contains small amounts of iodine, which can be isolated by various chemical processes. One such process involves treating the brine with chlorine to oxidize the iodide to iodine. The iodine is then separated from the solution by filtration and evaporation.
In conclusion, iodine is an essential nutrient that is required by the human body for the proper functioning of the thyroid gland. It is also used in various industrial and pharmaceutical applications. The three methods of preparing iodine are from seaweed, from iodides, and from brine. All three methods have their advantages and disadvantages, but they all serve the purpose of producing this vital element. It is essential to use iodine wisely and in appropriate quantities to avoid health complications.