Potassium tetraiodomercurate(II)

Last updated
Potassium tetraiodomercurate(II)
Potassium tetraiodomercurate(II).png
Potassium tetraiodomercurate(II)-3D-vdW.png
Names
IUPAC name
potassium tetraiodidomercurate(II)
Other names
potassium mercuric iodide,
Nessler's reagent (principal component)
Identifiers
3D model (JSmol)
ChEBI
ChemSpider
ECHA InfoCard 100.029.082 OOjs UI icon edit-ltr-progressive.svg
EC Number
  • 231-990-4
PubChem CID
UNII
UN number 3287
  • InChI=1S/Hg.4HI.2K/h;4*1H;;/q+2;;;;;2*+1/p-4 X mark.svgN
    Key: OPCMAZHMYZRPID-UHFFFAOYSA-J X mark.svgN
  • [K+].[K+].I[Hg-2](I)(I)I
Properties
K2[HgI4] [1]
Molar mass 786.406 g·mol−1
Appearanceyellow crystals
Odor odorless
Density 4.29 g/cm3
very soluble
Solubility soluble in alcohol, ether, acetone
Hazards
Safety data sheet (SDS) External MSDS for Nessler's reagent
Related compounds
Other anions
Mercury(II) iodide
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
X mark.svgN  verify  (what is  Yes check.svgYX mark.svgN ?)

Potassium tetraiodomercurate(II) is an inorganic compound with the chemical formula K 2[ Hg I 4]. It consists of potassium cations and tetraiodomercurate(II) anions. It is the active agent in Nessler's reagent, used for detection of ammonia. [2]

Contents

Preparation

The compound crystallizes from a heated solution of mercuric iodide, potassium iodide, and precisely 2% water in acetone. Attempted synthesis in concentrated aqueous solution will give the pale orange monohydrate K[Hg(H2O)I3] instead. [3]

Applications

K2[HgI4] is a precursor to analogous copper and silver salts M2[HgI4] (M=Cu, Ag). [4]

Nessler's reagent

Nessler's reagent, named after Julius Neßler (Nessler), is a 0.09 mol/L solution of potassium tetraiodomercurate(II) in 2.5 mol/L potassium hydroxide. This pale solution becomes deeper yellow in the presence of ammonia (NH3). At higher concentrations, a brown precipitate derivative of Millon's base (HgO·Hg(NH2)Cl) may form. The sensitivity as a spot test is about 0.3 μg  NH3 in 2 μL. [5]

NH+4 + 2 [HgI4]2− + 4 OH− → HgO·Hg(NH2)I↓ + 7 I− + 3 H2O

The brown precipitate is not fully characterized and may vary from HgO·Hg(NH2)I to 3HgO·Hg(NH3)2I2. [6]

Related Research Articles

<span class="mw-page-title-main">Zinc carbonate</span> Chemical compound

Zinc carbonate is the inorganic compound with the formula ZnCO3. It is a white solid that is insoluble in water. It exists in nature as the mineral smithsonite. It is prepared by treating cold solutions of zinc sulfate with potassium bicarbonate. Upon warming, it converts to basic zinc carbonate (Zn5(CO3)2(OH)6).

Classical qualitative inorganic analysis is a method of analytical chemistry which seeks to find the elemental composition of inorganic compounds. It is mainly focused on detecting ions in an aqueous solution, therefore materials in other forms may need to be brought to this state before using standard methods. The solution is then treated with various reagents to test for reactions characteristic of certain ions, which may cause color change, precipitation and other visible changes.

<span class="mw-page-title-main">Mercury(I) chloride</span> Chemical compound

Mercury(I) chloride is the chemical compound with the formula Hg2Cl2. Also known as the mineral calomel (a rare mineral) or mercurous chloride, this dense white or yellowish-white, odorless solid is the principal example of a mercury(I) compound. It is a component of reference electrodes in electrochemistry.

<span class="mw-page-title-main">Cadmium chloride</span> Chemical compound

Cadmium chloride is a white crystalline compound of cadmium and chloride, with the formula CdCl2. This salt is a hygroscopic solid that is highly soluble in water and slightly soluble in alcohol. The crystal structure of cadmium chloride (described below), is a reference for describing other crystal structures. Also known are CdCl2•H2O and the hemipentahydrate CdCl2•2.5H2O.

<span class="mw-page-title-main">Copper(I) iodide</span> Chemical compound

Copper(I) iodide is the inorganic compound with the formula CuI. It is also known as cuprous iodide. It is useful in a variety of applications ranging from organic synthesis to cloud seeding.

<span class="mw-page-title-main">Zinc iodide</span> Chemical compound

Zinc iodide is the inorganic compound with the formula ZnI2. It exists both in anhydrous form and as a dihydrate. Both are white and readily absorb water from the atmosphere. It has no major application.

The bead test is a traditional part of qualitative inorganic analysis to test for the presence of certain metals. The oldest one is the borax bead test or blister test. It was introduced by Berzelius in 1812. Since then other salts were used as fluxing agents, such as sodium carbonate or sodium fluoride. The most important one after borax is microcosmic salt, which is the basis of the microcosmic salt bead test.

<span class="mw-page-title-main">Mercury(II) cyanide</span> Chemical compound

Mercury(II) cyanide, also known as mercuric cyanide, is a poisonous compound of mercury and cyanide. It is an odorless, toxic white powder. It is highly soluble in polar solvents such as water, alcohol, and ammonia, slightly soluble in ether, and insoluble in benzene and other hydrophobic solvents.

<span class="mw-page-title-main">Sodium hexanitritocobaltate(III)</span> Chemical compound

Sodium hexanitritocobaltate(III) is inorganic compound with the formula Na3[Co(NO2)6]. The anion of this yellow-coloured salt consists of the transition metal nitrite complex [Co(NO2)6]3−. It was a reagent for the qualitative test for potassium and ammonium ions.

<span class="mw-page-title-main">Mercury(II) iodide</span> Chemical compound

Mercury(II) iodide is a chemical compound with the molecular formula HgI2. It is typically produced synthetically but can also be found in nature as the extremely rare mineral coccinite. Unlike the related mercury(II) chloride it is hardly soluble in water (<100 ppm).

<span class="mw-page-title-main">Mercury(II) acetate</span> Chemical compound

Mercury(II) acetate, also known as mercuric acetate is a chemical compound, the mercury(II) salt of acetic acid, with the formula Hg(O2CCH3)2. Commonly abbreviated Hg(OAc)2, this compound is employed as a reagent to generate organomercury compounds from unsaturated organic precursors. It is a white, water-soluble solid, but some samples can appear yellowish with time owing to decomposition.

<span class="mw-page-title-main">Cadmium iodide</span> Chemical compound

Cadmium iodide is an inorganic compound with the formula CdI2. It is a white hygroscopic solid. It also can be obtained as a mono- and tetrahydrate. It has few applications. It is notable for its crystal structure, which is typical for compounds of the form MX2 with strong polarization effects.

Germanium iodides are inorganic compound with the formula GeIx. Two such compounds exist: germanium(II) iodide, GeI2, and germanium(IV) iodide GeI4.

<span class="mw-page-title-main">Mercury(II) bromide</span> Chemical compound

Mercury(II) bromide or mercuric bromide is an inorganic compound with the formula HgBr2. This white solid is a laboratory reagent. Like all mercury salts, it is highly toxic.

<span class="mw-page-title-main">Potassium amide</span> Chemical compound

Potassium amide is an inorganic compound with the chemical formula KNH2. Like other alkali metal amides, it is a white solid that hydrolyzes readily. It is a strong base.

In chemistry and physics, the iron group refers to elements that are in some way related to iron; mostly in period (row) 4 of the periodic table. The term has different meanings in different contexts.

<span class="mw-page-title-main">Borate esters</span> Organic compounds of the form B(OR)₃ or B₃O₃(OR)₃

In organic chemistry, borate esters are organoboron compounds which are conveniently prepared by the stoichiometric condensation reaction of boric acid with alcohols. There are two main classes of borate esters: orthoborates, B(OR)3 and metaborates, B3O3(OR)3. Metaborates contain 6-membered boroxine rings.

<span class="mw-page-title-main">Arthur Vogel (chemist)</span> Author and educator (1905–1966)

Arthur Israel Vogel was a British chemist known for his Chemistry textbooks. He became the head of the chemistry department at Woolwich Polytechnic at the age of 27.

<span class="mw-page-title-main">Lutetium(III) iodide</span> Chemical compound

Lutetium(III) iodide or lutetium iodide is an inorganic compound consisting of iodine and lutetium, with the chemical formula of LuI3.

References

  1. ↑ Lide, David R., ed. (2009). CRC Handbook of Chemistry and Physics (90th ed.). Boca Raton, Florida: CRC Press. p. 4-82. ISBN   978-1-4200-9084-0.
  2. ↑ Vogel, Arthur I.; Svehla, G. (1979), Vogel's Textbook of Macro and Semimicro Qualitative Inorganic Analysis (5th ed.), London: Longman, ISBN   0-582-44367-9 – via the Internet Archive
  3. ↑ Wagenknecht, F.; Juza, R. (1963). "Potassium Triiodomercurate(II)". In Brauer, G. (ed.). Handbook of Preparative Inorganic Chemistry. Vol. 1 (2nd ed.). Academic Press. p. 1100 – via the Internet Archive.
  4. ↑ Wagenknecht, F.; Juza, R. (1963). "Copper(I) Tetraiodomercurate(II)". In Brauer, G. (ed.). Handbook of Preparative Inorganic Chemistry. Vol. 1 (2nd ed.). Academic Press. p. 1100 – via the Internet Archive.
  5. ↑ Vogel, Arthur I. (1954), A Textbook of Macro and Semimicro Qualitative Inorganic Analysis (4th ed.), London: Longman, p. 319, ISBN   0-582-44367-9
  6. ↑ Vogel, Arthur I.; Svehla, G. (1979), Vogel's Textbook of Macro and Semimicro Qualitative Inorganic Analysis (5th ed.), London: Longman, pp. 293–294, ISBN   0-582-44367-9 – via the Internet Archive
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.