Jodek

Jodek is the Polish term for iodide, the anion I− derived from iodine. In chemistry, jodek denotes salts and compounds that contain the iodide ion. The most common jodek salts are potassium iodide (jodek potasu, KI) and sodium iodide (jodek sodu, NaI). These salts are widely used in industry, medicine, and nutrition, and they form when iodide combines with various cations.

In aqueous solution, iodide is typically colorless and acts as a mild reducing agent. It can be oxidized to elemental iodine (I2) by various oxidizing agents such as chlorine, bromine, or hydrogen peroxide. Iodide also participates in qualitative tests; a common test is the formation of a blue-black color when iodide is present in the presence of starch and iodine forms within the solution.

Solubility varies among iodide salts. Many iodide salts are highly soluble in water, but some silver iodide (AgI) and lead(II) iodide (PbI2) are poorly soluble and can form precipitates, which are useful in qualitative analysis and in certain practical applications.

Occurrence and production: iodide occurs naturally in seawater and brines and can be recovered and converted into iodide salts for commercial use. Industrially, iodide can be produced or regenerated from iodine-containing compounds through appropriate chemical processes and neutralization steps to yield salts such as KI or NaI.

Uses: iodide is essential as a dietary supplement through iodized salt, helping prevent iodine deficiency. In medicine, potassium iodide is used as a thyroid-blocking agent in radioprotection and has various clinical applications. Iodide salts also have roles in organic synthesis and have historical importance in photography, where iodide-containing compounds were used in silver halide emulsions.

Safety: excessive iodide intake can affect thyroid function and overall health. Proper handling and adherence to regulatory guidelines are important, especially in medical or dietary contexts.