Potassium Iodide - KI - Chemically

Chemical formula: KI

Synonyms: iodide of potassium

Amount: 100 g

Appearance and odour: white powder without any appreciable odour

Grade: Chemically pure

Packaging: professional wide necked, white HDPE bottle with blue conical seal cap and tamper ring. Labelled. Bottle and cap are UN approved and reusable.

Description and uses: iodine’s main water soluble compound.

Lugol's Iodine Solution

This grade shows no signs whatsoever of oxidation: pure white KI contains no free iodine (I2, which causes KI to take on a yellow hue).

With chlorine gas or by electrolysis the iodide is converted to violet elemental iodine (I2).

Elemental iodine is highly soluble in KI solutions forming potassium triiodide (KI3).

With copper (cupric) salts, insoluble cuprous iodide (CuI) and elemental iodine is formed:

Cu2+(aq) + 2 I-(aq) === > CuI(s) + ½ I2(aq)

This reaction is used in analytical chemistry to standardise oxidising solutions like sodium thiosulphate (Na2S2O3), by back titrating the iodine released by reacting a precisely known quantity of cupric salt with an excess of KI.

Iodine is an essential part of our diet. Iodine supplements (in the form of potassium iodide) are used to fight certain diseases. Iodine supplements are also administered in areas afflicted by nuclear disasters to substitute any intake of radioactive iodine 135.