Ammonium mercuric thiocyanate

Mercuric thiocyanate, which is formed as a white precipitate when mercuric nitrate and potassium thiocyanate solutions are mixed, is soluble in excess of either solution. When dried, this salt is inflammable, forming a voluminous ash known as Pharaoh s serpents. By the interaction of a mercuric salt with ammonium thiocyanate and thio-carbamide in acetic acid solution in the presence of an oxidising agent, or by the action of hydrogen sulphide on mercuric thiocyanate, the phototropic compound HS.Hg.CNS is obtained.6... 

Prepare an analar solution of 12 g ammonium ferric sulphate in water and add 40 ml of analar nitric acid. Dilute to 100 ml. Prepare a solution containing 0.4 g of mercuric thiocyanate crystals in 100 ml of absolute alcohol. Mix 5 ml of the test solution from the oxygen flask combustion method (described above) with the ammonium ferric sulphate solution. Add 1.5 ml of mercuric thiocyanate solution. When chlorine is present an orange to red colour will develop in the test sample. If a semi-quantitative estimation of chlorine is required, set the solution aside for 10 min, then measure the optical density of this coloured solution against the blank solution at 460 nm in 20 mm cells. Typical calibration figures for the examination of plastic coatings such as PVC are as follows ... 

Ferric thiocyanate, Fe(CNS)3, has a characteristic blood-red color it is formed when a soluble thiocyanate is added to a ferric salt. The reactiton furnishes a convenient test for ferr salts or a thiocyanae. The so-called Pharaoh s serpents are made from mercuric thiocyanate. Ammonium thiocyanate, NH4CNS, is converted by heat into thiourea, SC(NH2)2, the reactions of which are analogous to those of urea, CO(NH2)2. 

Sulphate, chloride (Cl ), nitrate (NO ), and ammonium (NH ) in water were measured with a Technicon Autoanalyzer II system by the methylthymol blue, mercuric thiocyanate, cadmium reduction and sodium nitroprusside methods, respectively. Sulphate and Cl in highly colored samples were measured by means of ion chromatography. Cations were analyzed with an atomic-absorption spectrophotometer by means of flame-emission spectrophotometry for potassium (K ) and... 

Soliman and Belal investigated argentimetric (67,68) and mercurimetric (69) methods. Hydralazine precipitates silver from ammoniacal silver nitrate solution. The silver is dissolved with hot nitric acid and titrated with ammonium thiocyanate solution. Alternatively, mercury is precipitated from alkaline potassium mercuric iodide solution. The precipitated mercury is dissolved by adding excess standard iodine solution. The excess iodine is back-titrated with sodium thiosulfate solution after acidifying with acetic acid. 

Arsenic triiodide also dissolves, the saturated solution at 15° C. having density 3-661. Other soluble halides are potassium bromide, anhydrous ferric and aluminium chlorides 6 and tetramethyl ammonium iodide but the iodides of rubidium, cadmium, manganese and cobalt, also mercuric and stannic iodides, and cobalt and stannic bromides, are insoluble or only very slightly soluble in arsenic tribromide. The liquid also dissolves phosphoryl bromide and, very slightly, ammonium thiocyanate. In the mixed solutions of halides, the components may react chemically (cf. p. 106), but such is not always the case for example, with antimony tribromide a continuous series of solid solutions is formed.7... 

Thiourea is tbimed by heating ammonium thiocyanate at 170°C. After about an hour, 25% conversion is achieved. With HQ, thiourea forms thiourea hydrochloride with mercuric oxide, thiourea forms a salt and with silver chloride, it forms a complex salt. 

When hydrogen sulfide reacts, with mercuric chloride in neutral or acid solution, or when mercury and sulfur are ground together, black mercuric sulfide is formed. Under certain conditions, this material can be converted into the red modification by the continued action of soluble alkali sulfides. The reaction of mercuric chloride and sodium thiosulfate gives the red form if the ratio of the concentrations is higher than 1 4d The red sulfide is also produced when the substance Hg(SH)NCS is boiled with concentrated ammonium thiocyanate solution or when hydrogen sulfide is conducted into a warm mercuric salt solution in the presence of acetic acid and an excess of ammonium thiocyanate, or thiourea.2,3... 

Thirty-five grams of mercuric acetate and 25 g. of ammonium thiocyanate are dissolved in 100 ml. of hot glacial acetic acid. A steady stream of hydrogen sulfide is conducted into the hot solution until precipitation is complete. Then the acetic acid is slowly evaporated. (Caution Hydrogen cyanide gas is evolved.) The black precipitate that first appears slowly changes to the red modification as the acid boils away. Until this change is... 

Visual titration was also reported, the excess of silver being titrated with potassium thiocyanate in the presence of ferric ammonium sulfate indicator [51]. Mercuric nitrate titrations were also reported [62]. 

Mercuric Nitrate, 0.1 M [32.46 g Hg(N03)2 per 1000 mL] Dissolve about 35 g of mercuric nitrate [Hg(N03)2-H20] in a mixture of 5 mL of nitric acid and 500 mL of water, and dilute with water to 1000 mL. Standardize the solution as follows Transfer an accurately measured volume of about 20 mL of the solution into an Erlenmeyer flask, and add 2 mL of nitric acid and 2 mL of Ferric Ammonium Sulfate TS. Cool to below 20°, and titrate with 0.1 N Ammonium Thiocyanate to the first appearance of a permanent brown color. Calculate the molarity. 

When it is not possible to employ potassium chloride solution, e.g., if one of the junction solutions contains a soluble silver, mercurous or thallous salt, satisfactory results can be obtained with a salt bridge containing a saturated solution of ammonium nitrate the use of solutions of sodium nitrate and of lithium acetate has also been suggested. For non-aqueous solutions, sodium iodide in methyl alcohol and potassium thiocyanate in ethyl alcohol have been employed. 

This compound undergoes rearrangement the same as ammonium cyanate and thio-urea is obtained. With a soluble mercuric salt ammonium thiocyanate precipitates mercuric thio-cyanate which on heating swells up into phantastic shapes which are known as Pharaoh s serpents. The alkyl thio-cyanates are known and have been discussed (p. 74). Allyl-thio-cyanate is a constituent of oil of garlic. These... 

More recent investigators contend that salicylic acid can only be mercurated to give pure products when mercuric sulphate is used. A mixture of the anhydrides of o- and p hydroxymercuri-salicylic acids is formed, the latter 3delding p-thiocyanomercuri-salicylic acid with potassium or ammonium thiocyanates, and sodium p-sodium sulphitomercuri-salicylate with sodium sulphite. 

MERCURIC NITRATE (10045-94-0) A powerful oxidizer. Violent reaction with reducing agents, combustibles, phosphinic acid, hypophosphoric acid, petroleum hydrocarbons. Forms heat- and/or shock-sensitive compounds with acetylene (forms mercury acetylide), ethanol (forms mercury fulminate), ferrocene, isobutene, phosphine, potassium cyanide, sulfur. Incompatible with strong acids, acetic anhydride, ammonia, ammonium hexacyanofer-rate(II), organic azides, citric acid, hydrazinium perchlorate, isopropyl chlorocarbonate, nitrosyl perchlorate, sodium thiosulfate, sulfamic acid, thiocyanates, hydrozoic acid, methyl isocyanoacetate, sodium peroxyborate, trinitrobenzoic acid, urea nitrate. Aqueous solution corrodes metals. 

S 13.78%. Occurs in nature as the mineral cinnabar. Prepd from mercuric acetate, ammonium thiocyanate, glacial acetic acid and hydrogen sulfide Newell et al, Inorg. Syn, 1, 19 (1939). See also Colour Index vol. 4 (3rd ed.. 1971) p 4682. 

Light yellow, odorless powder slowly darkened by light. Crystals are hexagonal Or cubic, d 5.67 mp 552. Practically insol in water (0.03 mg/l) in acid (except coned HI in which it dissolves readily on heating) in ammonium carbonate. Freely sol in solns of alkali cyanides or iedides 35 mg dissolve in a liter of 10% ammouia appreciably sol in coned solns of alkali bromides, chlorides, thiocyanates, thiosulfates, mercuric and silver nitrates. It is slowly attacked by boiling coned acids, but not affected by hot solns of alkali hydroxides. 

The formation of (II) provides a quite selective spot test for palladium. Gold must be removed prior to the test because it will cause the development of a deep ruby red in the spot plate test and a diffused violet spot on the paper, apparently due to the reduction of the gold ions to the colloidal metal. Interference may also arise from 0s04 , Os+, Ru+, and RuCle ions because they have distinct self-colors. Mercurous ion causes partial interference by the reduction of part of the palladium to the elementary state, but a positive response can still be seen. It is possible to detect I part of palladium in the presence of 200 parts of platinum or 100 parts of rhodium. Less favorable ratios should be avoided because of the color of these salts. No interference is caused by mercuric and iridic chloride, but free ammonia, ammonium ions, stannous, cyanide, thiocyanate, fluoride, oxalate, and tetraborate ions do interfere. Lead, silver, ferrous, ferric, stannic, cobaltous, nickel, cupric, nitrite, sulfate, chloride, and bromide ions do not interfere. 

MF also decomposes by the action of inorganic salts such as sulfides, or thiosulfates. MF decomposes to mercuric sulfide by action of aqueous alkaline sulfides. This method of decomposition is used for elimination of MF from waste water [12, 42] or for decomposition of small quantities of solid MF in which case warm ammonium sulfide solution is recommended [38]. The reaction of MF with sulfides or hydrogen sulfide is fast when boiling the mixture, but slow at ambient temperature. Alkaline thiocyanates give the MF double salts (e.g., Hg (CN0)2 KSCN) [15]. The reaction with thiosulfates is very well documented because it is sometimes used for quantitative analysis of MF [10, 15, 29, 35, 58] ... 

Weigh an amount equivalent to 0-1 g of yellow mercuric oxide into a stoppered flask with the aid of 20 ml of chloroform, add 10 ml of dilute nitric acid and 20 ml of water and shake until the mercuric oxide is dissolved. Add 50 ml of water and titrate with 0-IN ammonium thiocyanate, at a temperature not exceeding 20°, using ferric alum as indicator. 1 ml 0-lN = 0-01083 g. 

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