Ferric chloride, solution preparation

P Keto esters (t.g., ethyl ocetoacetate) are soluble in solutions of caustic alkalis but not in sodium carbonate solution. They give colours with freshly prepared ferric chloride solution a little alcohol should be added to bring the ester into solution. Sodium ethoxide solution reacts to yield sodio compounds, which usually crystallise out in the cold. Phenylhydrazine yields pyrazolones. They are hydrolysed by boiling sulphuric acid to the Corresponding ketones, which can be identified as usual (Section 111,74). 

A fairly general procedure consists in coupling a phenol or naphthol with a diazotised amine, reducing the product to an aminophenol or aminonaphthol, and oxidising the hydroxy compound with acid ferric chloride solution. This method is illustrated by the preparation of (3 (or 1 2)-naphthoquinone ... 

Prepare the neutral ferric chloride solution (i.e., free from hydrochloric acid) by adding dilute sodium hydroxide solution dropwise to the bench reagent until a slight precipitate of ferric hydroxide is formed. Filter off the precipitate and use the clear filtrate for the test. 

Recommended practice for examination and evaluation of pitting corrosion Test method for determining susceptibility to stress corrosion cracking of high-strength aluminium alloy products Test method for pitting and crevice corrosion resistance of stainless steels and related alloys by the use of ferric chloride solution Recommended practice for preparation and use of direct tension stress corrosion test specimens... 

Experiment 5. Angeli-Rimini Reaction.—A few drops of an aldehyde (any of those prepared) are dissolved in aldehyde-free 1 alcohol and about the same amount of benzene sulphohydroxamic acid (for the preparation of which see p. 192) is added in the case of aliphatic substances, twice as much of the acid is used. To this mixture, kept cool and shaken, 2 A-sodium hydroxide is added, in an amount judged to be about two molecular proportions. After standing for fifteen minutes the alkaline mixture is made just acid to Congo red and finally a drop of ferric chloride solution is added. An intense red colour is produced. 

Another system under investigation is the iron/ chromium redox flow battery (Fe/Cr RFB) developed by NASA. The performance requirements of the membrane for Fe/Cr RFB are severe. The membrane must readily permit the passage of chloride ions, but should not allow any mixing of the chromium and iron ions. An anionic permselective membrane CDIL-AA5-LC-397, developed by Ionics, Inc., performed well in this system. ° It was prepared by a free radical polymerization of vinylbenzyl chloride and dimethylaminoethyl methacrylate in a 1 1 molar ratio. One major issue with the anionic membranes was its increase in resistance during the time it was exposed to a ferric chloride solution. The resistance increase termed fouling is related to the ability of the ferric ion to form ferric chloride complexes, which are not electrically repelled by the anionic membrane. An experiment by Arnold and Assink indicated that... 

Precipitation of ferric hydroxide gel was also observed in the preparation of spindlelike hematite (a-Fe203) particles in a dilute ferric chloride solution in the presence of phosphate (9). In this case, however, the positive role of the gel was not definite since similar uniform hematite paricles were obtained as well in homogeneous systems in the presence of the same anions (9). Also, Hamada and Matijevic (10) prepared uniform particles of pseudocubic hematite by hydrolysis of ferric chloride in aqueous solutions of alcohol (10-50%) at I00°C for several days. In this reaction, it was observed that acicular crystals of (3-FeOOH precipitated first, and then they dissolved with formation of the pseudocubic particles of hematite. The intermediate P-FeOOH appears to work as a reservoir of the solute to maintain an ideal supersaturation for the nucleation and growth of the hematite. Since the (3-FeOOH as an intermediate and the pseudocubic shape tire not peculiar to the alcohol/water medium... 

Ferrous Salt. — On first removing the superficial layers of a crystal by washing with water, and then preparing a 3 per cent aqueous solution from the washed crystals, the solution must not acquire a blue color on the addition of a few drops of a dilute ferric chloride solution. 

Salicylic Acid, ioo c.c. of the milk are shaken with ioo c.c. of hot water (6o°), 8 drops of acetic acid and 8 drops of mercurous nitrate solution and filtered, the filtrate being shaken with 50 c.c. of a mixture of ether and petroleum ether in equal volumes. The ethereal layer is then separated and the solvent evaporated, the residue being dissolved in a little water and treated with a few drops of a recently prepared 005% ferric chloride solution a violet coloration indicates salicylic add. 

Wear nitrile gloves, laboratory coat, and eye protection. Work in the fume hood. Dilute the solution of cyanide with water to a concentration not greater than 2%. For each 50 mL of solution, slowly add, while stirring, 5 mL of 10% sodium hydroxide solution, and 60-70 mL of household bleach. Test the solution for continued presence of cyanide as follows. Remove about 1 mL of the solution and place in a test tube. Add 2 drops of a freshly prepared 5% aqueous ferrous sulfate solution. Boil the mixture for 30 seconds, cool to room temperature, and add 2 drops of 1% ferric chloride solution. Acidify the mixture to litmus with 6 M hydrochloric acid (slowly add concentrated acid to an equal volume of cold water). If cyanide is still present, a deep blue precipitate forms. If the test... 

Potassium Cyanide Solutions. Wear breathing apparatus, eye protection, laboratory coat, and butyl rubber gloves. Instruct others to keep a safe distance. Cover the spill with a 1 1 1 mixture by weight of sodium carbonate or calcium carbonate, clay cat litter (bentonite), and sand. Scoop the mixture into a container and transport to the fume hood. Slowly, and while stirring, add the slurry to a pail containing household bleach (about 70 mL/g of cyanide). Test the solution for the presence of cyanide using the Prussian blue test. To 1 mL of the solution, add 2 drops of a freshly prepared 5% aqueous ferrous sulfate solution. Boil the mixture for at least 60 seconds, cool to room temperature and add 2 drops of 1 % ferric chloride solution. Add 6 M hydrochloric acid (prepared by... 

It is possible also to prepare colloidal ferric hydroxide with a negative charge. This may be done by adding slowly 100 c.c. of 0 01-normal ferric chloride solution to 150 c.c. of 0-01-normal sodium hydroxide, the mixture being continuously shaken during the process.2... 

Attempts to determine the molecular weight of colloidal ferric hydroxide lead to very high values. Thus, a colloidal solution prepared by addition of ammonium carbonate to ferric chloride solution was purified by dialysis, and the freezing-point determined of that portion which would not pass through a collodion membrane. The point was only slightly lower than that of the filtrate, indicative of a molecular weight of 3120 for the colloid.2... 

For the preparation of the pure salt, Caven 2 recommends addition of ferric chloride solution to one of orthophosphoric acid—made by boiling glacial metaphosphoric acid with water until it ceases to give any precipitate with barium chloride—m such proportions that rather more than twice as much acid, calculated as H3P04, is present as is required to precipitate the iron. The precipitate thus obtained appears, when suspended in water, perfectly white when strained on calico, it possesses a slightly bluish tint. Since hot water hydrolyses the salt, the washing should be conducted in the cold. 

Ferric carbonyl ferrocyanide, Fe[Fe(CN)5CO], is prepared by double decomposition of an excess of ferric chloride solution and the potassium salt.1 It resembles indigo in appearance, and contains about 4 per cent, of combined water.2 Dried at a moderate temperature, it yields a friable resinous mass with a brilliant conchoidal fracture.1... 

Identification of Salicylic Acid in Horse Urine No statutory limit is prescribed for salicylic acid, but it is normally present in horse urine it is important, therefore, to distinguish between normal concentrations and those arising from medication with aspirin or other salicylates such as topically applied methyl salicylate. Normal urine concentrations rarely exceed 10 LLg/ml, but therapeutic doses of aspirin may give concentrations as much as 500 times greater. Addition of 1 ml of freshly prepared ferric chloride solution to 5 ml of urine will give a detectable violet colour when the concentration of salicylic acid exceeds about 100 ig/ml. A positive result should be followed... 

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