Difference Between Iodine and Potassium Iodide

Iodine vs Potassium Iodide

Iodine and Potassium Iodide are essential element and compound respectively. Iodine is classified as halogen in periodic table, represented by the symbol I and has the atomic number 53. Like all other halogens it is found in diatomic. Iodine is one of the most powerful disinfectants. It is commonly used in table salt and is essential part of the diet that saves from iodine deficiency. Iodine helps thyroid gland to produce thyroxin hormones essential for the body. Potassium iodide is the compound formed by the combination of potassium and iodine represented by KI. Potassium iodide has various uses the main one being taken as tablets as the treatment against radioactive exposure. KI is added to table salt to make it iodized.


Iodine appears blue black but gets converted into violet colored gas at room temperature. Iodine has a pungent and non pleasant odor and is less reactive than other halogens. Iodine is not an abundant element found on earth but because it has a high atomic number, very low toxicity level and its property to form compounds easily has made it an important element to be used in various ways. Iodine deficiency in humans leads to mental retardation and affects the normal functioning of thyroid gland. There are 37 known isotopes, of these iodine-131 is a common nuclear fission product that accumulates in thyroid glands and is highly carcinogenic. Iodine is industrially used as catalyst in the production of acetic acid. Iodine tincture is used as disinfectant.

Potassium iodide

It is an inorganic compound and appears as white solid and is produced commercially in large quantities. It is the most important iodide compound because it is less hygroscopic than any other iodide compounds. The most important application of KI is in the form of SSKI (saturated solution of potassium iodide also) tablets. These tablets are taken in emergency treatment of several ailments. SSKI is also used for the treatment in the cases of exposure to nuclear accidents. KI is also used to supplement iodine deficiency when added to table salt. KI is an important compound that is used in photography industry and in the field of biomedical research.


Iodine being a halogen cannot remain as an element under standard temperature and pressure but combines with other elements to form compounds easily. It is this property to form compounds that makes it a very important element. Iodine combines with potassium to form potassium Iodide which is a very important compound that is commercially used in various industries. Iodine isotopes are dangerous for the humans but when this iodine is taken in the form of KI it becomes human beings good friend. Iodine deficiency leads to mental retardation and goiter, this deficiency is fulfilled by the administration of iodine in the form of KI. Iodine appears to be bluish black whereas KI appears as white solid. Iodine is mainly used as disinfectant and KI is mainly used as nutritional supplement and as medicine to be used in treatment of many diseases.