Which two of the following salts are used for preparing iodized salt? (1) \(\mathrm{KIO}_{3}\) (2) KI (3) \(\mathrm{I}_{2}\) (4) HI (a) (i) and (ii) (b) (i) and (iii) (c) (ii) and (iv) (d) (iii) and (iv)

Potassium iodate (KIO3) is a key substance used in the process of enriching table salt with iodine, an essential trace element required for human health. It's an inorganic compound that serves as a stable source of iodine. Unlike iodine in its elemental state, KIO3 is not volatile and does not pose a risk of evaporation when mixed with salt. This property makes it an excellent choice to ensure a consistent amount of iodine is present in the salt over time.

In the preparation of iodized salt, a specific amount of KIO3 is sprayed onto the salt and thoroughly mixed to achieve uniform distribution. The amount used is carefully calculated to meet the dietary requirements of iodine without excess, which is critical to prevent any potential negative health effects associated with high iodine intake.

Potassium iodide (KI) is another compound commonly used in iodizing table salt. It is more than just an additive for salt; it's also well-known for its medicinal uses, such as protecting the thyroid gland from radiation by saturating thyroid tissue with stable iodine. When used in the iodization of salt, KI is favored for its high solubility in water and its ability to quickly supply the body with the necessary iodine.

Similar to potassium iodate, KI is also evenly mixed with table salt in a meticulous process to ensure an even distribution. One of the advantages of potassium iodide in table salt is that it is readily bioavailable, meaning that once ingested, the body can easily absorb and utilize the iodine to support vital bodily functions.

Iodine deficiency is a significant health concern that can lead to various medical conditions, most notably goiter -- the enlargement of the thyroid gland. This essential nutrient is also crucial for the production of thyroid hormones, which play a vital role in regulating metabolism, growth, and development. Deficiencies in iodine can lead to hypothyroidism, mental retardation in children, and various other developmental abnormalities.

Moreover, adequate iodine intake is particularly important for pregnant women as it supports fetal development. The World Health Organization (WHO) recommends iodine supplementation in regions where natural food sources are insufficient. Iodized salt has been a successful public health intervention in preventing iodine deficiency disorders in many parts of the world.

Table salt iodization is a public health measure aimed at eliminating iodine deficiency in populations. It involves adding a minute amount of iodine, in the form of potassium iodate or potassium iodide, to table salt, an item commonly consumed by people globally. This strategy is both cost-effective and has a broad reach, making it an ideal vehicle for iodine supplementation.

The process itself is straightforward but requires careful control to ensure that the correct amount of iodine is added. This is typically achieved through a standardized procedure where the iodizing agent is sprayed onto the salt as it moves through a conveyer or mixing device. The fortified salt is then packaged and distributed for consumption. Regular monitoring is also required to ensure that the iodine levels in the salt remain within the recommended limits and that the quality of the iodized salt is maintained.