The key difference between iodine and potassium iodide is that iodine is a chemical element whereas potassium iodide is a chemical compound.
Iodine is a halogen that locates in group 17 of the periodic table of elements. On the other hand, potassium iodide is a chemical compound that forms from the combination of iodine and potassium. As a result, potassium iodide is very useful in many industries as a source of iodine.
CONTENTS
1. Overview and Key Difference
2. What is Iodine
3. What is Potassium Iodide
4. Side by Side Comparison – Iodine vs Potassium Iodide in Tabular Form
5. Summary
What is Iodine?
Iodine is a chemical element having the atomic number 53 and chemical symbol I. It is the heaviest halogen among the other halogens. The halogens are group 17 chemical elements in the periodic table. Furthermore, iodine exists as a lustrous, metallic-grey solid at room temperature. However, it can readily undergo sublimation to form the violet gas of iodine. Moreover, among the oxidation states that iodine can exist, the -1 oxidation is the most common among them, which results in the iodide anion. It is because, the iodine has an incomplete octet in its electron configuration in which it requires an electron to complete the octet. Then, when it obtains an electron from outside, it forms the -1 oxidation state.
Some important facts about iodine are as follows:
- Atomic number – 53
- Standard atomic weight – 126.9
- Appearance – lustrous, metallic-grey solid
- Electron configuration – [Kr] 4d10 5s2 5p5
- Group – 17
- Period – 5
- Chemical category – nonmetal
- Melting point is 113.7 °C
- Boiling point is 184.3 °C
Moreover, iodine is a strong oxidizer. Mainly, it is due to its incomplete octet of electron configuration in which it lacks one electron to fill up the outermost p orbital. Thus, it seeks for an electron by oxidizing other chemical species. However, it is the weakest oxidizing agent among other halogens due to its large atomic size.
What is Potassium Iodide?
Potassium iodide 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 chemical formula of this compound is KI.
Some important chemical facts about this compound are as follows:
- Chemical formula – KI
- Molar mass – 166 g/mol.
- Melting point is 681 °C.
- Boiling point is 1,330 °C.
- It has the crystal structure of sodium chloride.
- A mild reducing agent.
- Production is industrially by treating KOH with iodine.
The most important application of KI is in the form of SSKI (saturated solution of potassium iodide also) tablets. These tablets are taken in the emergency treatment of several ailments. Also, SSKI is useful for the treatment in the cases of exposure to nuclear accidents. Furthermore, KI is a supplement for iodine deficiency when added to table salt. Moreover, we can use it in the photography industry and in the field of biomedical research.
What is the Difference Between Iodine and Potassium Iodide?
Iodine is a chemical element having the atomic number 53 and chemical symbol I whereas Potassium iodide is an inorganic compound and appears as white solid and is produced commercially in large quantities. Therefore, the key difference between iodine and potassium iodide is that iodine is a chemical element whereas potassium iodide is a chemical compound. In brief, iodine combines with potassium (e.g., KOH) to produce potassium iodide compound. As another important difference between iodine and potassium iodide, we can say that iodine has a lustrous, metallic-grey appearance whereas potassium iodide appears as a white solid compound.
Furthermore, there is a difference between iodine and potassium iodide in their usage as well. Also, there are few other differences in their chemical properties too. The below infographic summarizes the difference between iodine and potassium iodide in tabular form.
Summary – Iodine vs Potassium Iodide
Iodine being a halogen cannot remain as an element under standard temperature and pressure but combines with other elements to form compounds easily. Hence, it is this property to form compounds that make it a very important element. Therefore, the key difference between iodine and potassium iodide is that iodine is a chemical element whereas potassium iodide is a chemical compound. Iodine combines with potassium to form potassium Iodide which is a very important compound that is commercially useful in various industries. However, iodine isotopes are dangerous for humans, but when this iodine is taken in the form of KI, it becomes useful to humans. Moreover, iodine deficiency leads to mental retardation and goitre, this deficiency is fulfilled by the administration of iodine in the form of KI.
Reference:
1.“Iodine.” Wikipedia, Wikimedia Foundation, 20 Oct. 2018. Available here
2.“Potassium Iodide.” Wikipedia, Wikimedia Foundation, 26 Sept. 2018. Available here
Image Courtesy:
1.”Sample of iodine”By LHcheM – Own work, (CC BY-SA 3.0) via Commons Wikimedia
2.”Potassium iodide” (Public Domain) via Commons Wikimedia
Annette says
why is the iodine found in food capable of being absorbed and utilized by the body, think seaweeds and the Japanese diet being greater than the typical American diet. Could iodine through diet be just as beneficial to reverse an iodine deficiency? From the about article, I come away thinking that Potassium Iodide is the only/best way to reverse a deficiency. Or is it that lesser amounts of KI are needed and better absorbed than I ?
Pahoo says
The term “iodine” actually describes a single atom of iodide bound to either another atom of iodide or to another compound. “Nascent iodine” was once used as simply another name for sodium iodide (an iodide atom bound to sodium). The term was then used by the American mysticist, Edgar Cayce, to describe a free form of iodine (i.e., a single atom of iodide unbound to any other atom) – apparently created by adding electromagnetic or another form of energy. However, when this free form of iodide is exposed to a positively charged ion, such as sodium or potassium, as it would be in a liquid supplement, it will bind with these to form sodium iodide or potassium iodide. Therefore, if you are buying a supplement promoted as “nascent iodine”, it is most likely sodium iodide or potassium iodide. There do not appear to be any published, placebo-controlled studies on “nascent iodine” for thyroid support or any other use.
Expose Them511 says
Why would the medical industrial complex do this study when they can’t dominate the treatment and make merchandise of us? They don’t want you to heal; they want to “treat” you with one of their designer diseases that are the results of their bad medical and dietary advice or that come out of a syringe or pill bottle till you drop dead. They are in the business of self-aggrandizement and death, not altruism and health.
Pahoo says
First, since the Fukushima disaster I would strongly suggest staying away from seaweed sources of any kind unless you can confirm the source as being Atlantic Ocean.
Second, a food source is fine so long as it’s growth occurred in an Iodine rich soil, which are sadly lacking these days.
Lastly, nascent Iodine, followed by potassium iodide, are the best ‘artificial’ sources, as supplements. I have to investigate the statement in the article which apparently suggests that it may be necessary to take the potassium iodide (KI) with table salt (NaCl) for maximum absorption.