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An iodide ion is the ion I −. [2] Compounds with iodine in formal oxidation state −1 are called iodides. In everyday life, iodide is most commonly encountered as a component of iodized salt, which many governments mandate. Worldwide, iodine deficiency affects two billion people and is the leading preventable cause of intellectual disability ...
The iodine clock reaction is a classical chemical clock demonstration experiment to display chemical kinetics in action; it was discovered by Hans Heinrich Landolt in 1886. [1] The iodine clock reaction exists in several variations, which each involve iodine species (iodide ion, free iodine, or iodate ion) and redox reagents in the presence of ...
Hydrogen iodide. The simplest compound of iodine is hydrogen iodide, HI.It is a colourless gas that reacts with oxygen to give water and iodine. Although it is useful in iodination reactions in the laboratory, it does not have large-scale industrial uses, unlike the other hydrogen halides.
The initial aqueous solution contains hydrogen peroxide, an iodate, divalent manganese (Mn 2+) as catalyst, a strong chemically unreactive acid (sulphuric acid (H 2 SO 4) or perchloric acid (HClO 4) are good), and an organic compound with an active ("enolic") hydrogen atom attached to carbon which will slowly reduce free iodine (I 2) to iodide (I −).
In 1921, solid silver iodide (AgI) was found to have had extraordinary high ionic conductivity at temperatures above 147 °C, AgI changes into a phase that has an ionic conductivity of ~ 1 –1 cm −1. [clarification needed] This high temperature phase of AgI is an example of a superionic conductor.
The acid facilitates the conversion by the brown, Manganese-containing precipitate of the Iodide ion into elemental Iodine. The Mn(SO 4) 2 formed by the acid converts the iodide ions into iodine, itself being reduced back to manganese(II) ions in an acidic medium. Mn(SO 4) 2 + 2 I − (aq) → Mn 2+ (aq) + I 2 (aq) + 2 SO 2− 4 (aq)
For prolonged titrations, it is advised to add dry ice to the titration mixture to displace air from the Erlenmeyer flask so as to prevent the aerial oxidation of iodide to iodine. Standard iodine solution is prepared from potassium iodate and potassium iodide, which are both primary standards: IO − 3 + 8 I − + 6 H + → 3 I − 3 + 3 H 2 O
Of the halides, iodide usually is the best leaving group. Because of the weakness of the C–I bond, samples of organoiodine compounds are often yellow due to an impurity of I 2. A noteworthy aspect of organoiodine compounds is their high density, which arises from the high atomic weight of iodine.