Nessler's reagent

Nessler's reagent

Neßler's reagent is a reagent named after Julius Neßler and is used to detect small amounts of ammonia. It is a 0.09 mol/L solution of potassium tetraiodomercurate(II) (K2 [HgI4] ) in 2.5 mol/L potassium hydroxide. A yellow coloration indicates the presence of ammonia: at higher concentrations, a brown precipitate may form. The sensitivity as a spot test is about 0.3 μg NH3 in 2 μL.

:NH4+ + 2 [HgI4] 2− + 4OH− → HgO·Hg(NH2)I + 7I− + 3H2O

Toxicity

It is toxic if swallowed, inhaled or absorbed through the skin. It presents a neurological hazard and may act as a carcinogen and be a reproductive hazard. It is corrosive and causes burns.

Other names

Nessler's solution, mercuric potassium iodide, mercury(II) potassium iodide, Channing's solution, potassium mercuric iodide, potassium tetraiodomercurate(II)

Preparation

Nessler's reagent is generally prepared from potassium iodide and mercury(II) iodide. Hot concentrated solution of mercury(II) chloride is added to concentrated solution of potassium iodide, until the precipitate of mercury(II) iodide stops dissolving. The liquid is filtered, and potassium hydroxide and a further bit of mercury(II) chloride solution are added. The resulting solution is then cooled and diluted to required concentration. [http://www.fao.org/docrep/field/003/Q6501E/Q6501E05.htm]

References

*VogelQualitative

External links

* [http://www-cie.iarc.fr/htdocs/monographs/vol58/mono58-3.htm IARC Monograph: "Mercury and Mercury Compounds"]
* [http://www.npi.gov.au/database/substance-info/profiles/53.html National Pollutant Inventory - Mercury and compounds fact sheet]


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  • Nessler's reagent — Ness·ler s reagent nes lərz n an alkaline solution of potassium mercuric iodide used in chemical analysis esp. in a test for ammonia in aqueous solution (as when obtained from water, blood, or urine) with which it forms a yellowish brown color or …   Medical dictionary

  • nessler's reagent — noun or nessler s solution ˈneslə(r)z Usage: usually capitalized N Etymology: after Julius Nessler : an alkaline solution of potassium mercuric iodide used in chemical analysis especially in a delicate test for ammonia in aqueous solution (as… …   Useful english dictionary

  • Nessler's reagent — /nes leuhrz/ an aqueous solution of potassium iodide, mercuric chloride, and potassium hydroxide, used as a test for the presence of ammonia. Also called Nessler s solution. [1870 75; see NESSLERIZE] * * * …   Universalium

  • Nessler's reagent — n. Nessler s solution, water based solution of potassium hydroxide and mercuric iodide and potassium iodide (used to test and detect for the presence of ammonia) …   English contemporary dictionary

  • Nessler — Neßler, Nessler, Nesler are surnames of: Brad Nessler (born 1956, St. Charles, Minnesota), an American sportscaster Julius Neßler (1827–1905), a German chemist Nessler s reagent, after Julius Neßler Karl Ludwig Nessler (1872, Todtnau, Germany… …   Wikipedia

  • Nessler's solution — n. Nessler s reagent, water based solution of potassium hydroxide and mercuric iodide and potassium iodide (used to test and detect for the presence of ammonia) …   English contemporary dictionary

  • nessler's solution — noun see nessler s reagent …   Useful english dictionary

  • Nessler reagent (solution) — Ness·ler reagent (solution) (nesґler) [Julius Nessler, German chemist, 1827–1905] see under reagent …   Medical dictionary

  • Nessler reagent — Neslerio reagentas statusas T sritis chemija apibrėžtis KI, HgCl₂ ir KOH tirpalų mišinys. atitikmenys: angl. Nessler reagent rus. реактив Несслера …   Chemijos terminų aiškinamasis žodynas

  • Nessler's solution — Solution So*lu tion (s[ o]*l[=u] sh[u^]n), n. [OE. solucion, OF. solucion, F. solution, fr. L. solutio, fr. solvere, solutum, to loosen, dissolve. See {Solve}.] 1. The act of separating the parts of any body, or the condition of undergoing a… …   The Collaborative International Dictionary of English

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