Definition of Nessler's reagent in English:
Nessler's reagent
noun
(also Nessler reagent)
Chemistry An alkaline solution of mercuric iodide and potassium iodide, containing HgI₄ 2− ions, which gives a brown colour or precipitate when added to an aqueous solution containing ammonia. Similarly "Nessler('s) solution".
Origin
Mid 19th century; earliest use found in Journal of the Chemical Society.
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