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Reagent test Alcohols: Forms Lucas test in alcohols is a test to differentiate between primary, secondary, and tertiary alcohols. Alkaloids: Forms Froehde Liebermann Mandelin Marquis Mayer's Mecke Simon's: Amines, and amino acids: Forms Folin's: Barbiturates: Class Dille–Koppanyi Zwikker: Benzodiazepines: Class Zimmermann: Phytocannabinoids ...
Sodium iodide (chemical formula NaI) is an ionic compound formed from the chemical reaction of sodium metal and iodine. Under standard conditions, it is a white, water-soluble solid comprising a 1:1 mix of sodium cations (Na + ) and iodide anions (I − ) in a crystal lattice .
I 2 dissolves in the iodide-containing solution to give triiodide ions (I 3 −), which have a dark brown color. The triiodide ion solution is then titrated against standard thiosulfate solution to give iodide again using starch indicator: I − 3 + 2 e − ⇌ 3 I − (E 0 = +0.54 V) Together with reduction potential of thiosulfate: [1]
The color of the flames also generally depends on temperature and oxygen fed; see flame colors. [5] The procedure uses different solvents and flames to view the test flame through a cobalt blue glass or didymium glass to filter the interfering light of contaminants such as sodium. [12] Flame tests are subject of a number of limitations.
Melzer's reagent is an aqueous solution of chloral hydrate, potassium iodide, and iodine.Depending on the formulation, it consists of approximately 2.50-3.75% potassium iodide and 0.75–1.25% iodine, with the remainder of the solution being 50% water and 50% chloral hydrate.
Two intersecting lines are drawn on the surface of the cap, the first with aniline or aniline water, the second with an aqueous solution of 65% nitric acid. The test is considered positive when a bright orange color forms where the lines cross. [4] [5] [6] Agaricus placomyces and Agaricus xanthodermus produce false negative reactions. [4] [5]
This clock reaction uses sodium, potassium or ammonium persulfate to oxidize iodide ions to iodine. Sodium thiosulfate is used to reduce iodine back to iodide before the iodine can complex with the starch to form the characteristic blue-black color. Iodine is generated: 2 I − + S 2 O 2− 8 → I 2 + 2 SO 2− 4. And is then removed:
The main use of sodium iodate in everyday life is in iodised salt. The other compounds which are used in iodised table salt are potassium iodate, potassium iodide, and sodium iodide. Sodium iodate comprises 15 to 50 mg per kilogram of applicable salt. Sodium iodate is also used as a dough conditioner to strengthen the dough.