Protections silver® nitrate

In many cases the analytical grade material may be replaced by pure recrystallised silver nitrate, but in that case it is advisable to standardise the solution against sodium chloride. Solutions of silver nitrate should be protected from light and are best stored in amber-coloured glass bottles. 

Discussion. These anions are both determined as silver bromide, AgBr, by precipitation with silver nitrate solution in the presence of dilute nitric acid. With the bromate, initial reduction to the bromide is achieved by the procedures described for the chlorate (Section 11.56) and the iodate (Section 11.63). Silver bromide is less soluble in water than is the chloride. The solubility of the former is 0.11 mg L 1 at 21 °C as compared with 1.54 mg L 1 for the latter hence the procedure for the determination of bromide is practically the same as that for chloride. Protection from light is even more essential with the bromide than with the chloride because of its greater sensitivity (see Section 11.57). 

AgN03 = silver nitrate CICN = cyanogen chloride CN" = cyanide ion CNATC = cyanides not amenable to chlorination (Rosentreter and Skogerboe 1992) AAS = atomic absorption spectroscopy EPA = Environmental Protection Agency FIA = flow injection analysis GC/ECD = gas chromatograph/electron capture detector HCN = hydrogen cyanide NaOH = sodium hydroxide NIOSH = National Institute for Occupational Safety and Health... 

Silver nitrate, which is a caustic agent, is available as a stick or pen in combination with potassium nitrate and is suitable for the removal of warts on the hands and feet. It should be used with caution and patients are advised to protect the surrounding skin, as it can cause chemical burns. It can also cause staining of skin and fabric. 

Thus, the N,N-dibenzyl-protected aminonitrile 55 was prepared via Swern oxidation of N,N-dibenzylaminoethanol 54 followed by treatment with the enantio-pure amine auxiliary (S,S)-53 and HCN, resulting in the formation of a 3 2 epimeric mixture of the aminonitriles 55 in 55% yield, from which the single dia-stereomers could be isolated by chromatography. After lithiation with LDA, addition to the requisite (E)-a, P-unsaturated esters and hydrolysis of the aminonitrile moiety with silver nitrate, the desired a-amino keto esters R)-S6 were obtained with yields of 65-81% and enantiomeric excesses ee of 78-98%, which could be improved to ee > 98% by a simple recrystallization. Since the amino ketone functionality can be cleaved oxidatively, the 5-amino-4-oxo-esters 56 could be transformed to the corresponding succinic half-esters 57 with hydrogen peroxide in methanol in good to excellent yields (68-90%) (Scheme 1.1.15). 

Walcr-peptizable colloidal substances such as gelatin, dextrin, gum arable, and soap peptize many precipitates, and are often culled protective colloids. Gelatin in the solution prevents the precipitation of silver dichromatc upon mixing silver nitrate and potassium dichroinalc solutions. (See Condensation Processes, below.)... 

When dilute silver nitrate and dilute potassium bromide solutions are mixed so that there is a slight excess of either solution, silver bromide is peptized. Acheson s oil-dag and aqua-dag are suspensoids of graphite in oil ur water containing a protective colloid, lannin. Oil-dug contains about 15% of a "deflocculated graphite." and is used in dilute solution in luhricaling oil (about... 

Use of a protective colloid in solution prevents the formation of the ordinary and expected precipitate in many eases, and causes the formation of the expected substance -as colloidal sol. Silver nitrate (0.6 gram per liter and potassium dichromate (0.5 gram per liter) to one of which is added 0.1 volume of Itol gelatin solution (2 grains per 100 milliliters of water) are mixed with stirring silver dichromate sol is formed. 

There are two methods for the preparation of Cu-Ag double metal powder by replacement reaction. One is to react nano copper with silver nitrate solution directly in the existence of polymer protecting agent to produce Cu-Ag double metal powder, which, by TEM determination, appears usually in the form of twigs. In the other method, an Ag(NH i) + solution is used to replace the AgNOj solution to take part in the replacement reaction, and with the other conditions being the same as those in the former method, sphere particles can normally be obtained. The present study is aimed at the preparation of nano particles of sphere form, and so the second method is employed. 

Soluble in 350 parts water miscible with alcohol, ether, and oils. It reduces ammoniacal silver nitrate, but not Fehling s solution. Keep container tightly closed and protected from light.1... 

Small Quantities. Wear eye protection, laboratory coat, and nitrile rubber gloves. In the fume hood, add to an equal volume of sodium carbonate or calcium carbonate, and then add to a very large volume of water. Cautiously add calcium or sodium hypochlorite solution (household bleach). When reaction is complete (test with silver nitrate for completeness of reaction),8 dilute and neutralize. Let stand until solids settle. Liquid may be decanted into the drain with at least 50 times its volume of water. Solid residue may be discarded with normal refuse.6,7... 

Protected temporarily as an a-amino nitrile, SMA can be recovered in excellent yield after treatment with silver nitrate in acetonitrile.64... 

Numerous conditions have been developed for this transformation, but reproducible yields have usually been obtained by mixing a silver salt with a coreagent, such as silver nitrate associated with wet ammonia, silver oxide with triethylamine or sodium thiosulfate, and silver benzoate with triethylamine. Nonbasic conditions have also been described by Koch and Podlech using silver trifluoroacetate deposited on silica.6 These modifications have been developed for the homologation of Fmoc-protected amino acids. 

Silver nitrate, AgN03, can be used to test for the presence of halide ions in solution. It combines with the halide ions to form a silver halide precipitate. In medicine, it is used as an antiseptic and an antibacterial agent. Silver nitrate drops are placed in the eyes of newborn babies to protect them against an eye disease. 

Procedure Add 1 mL of 0.1 N silver nitrate to both the Test Solution and the Chloride Reference Solution. Mix, allow to stand for 5 min protected from direct sunlight, and compare the two solutions. The turbidity of the Test Solution is not greater than that of the Chloride Reference Solution. 

Procedure Unless otherwise directed, dissolve the specified amount of the test substance in 30 to 40 mL of water neutralize to litmus external indicator with nitric acid, if necessary and add 1 mL in excess. Add 1 mL of silver nitrate TS to the clear solution or filtrate, dilute to 50 mL with water, mix, and allow to stand for 5 min protected from direct sunlight. Compare the turbidity, if any, with that produced similarly in a control solution containing the required volume of Standard Chloride Solution and the quantities of the reagents used for the sample. 

While protected from light, a saturated solution of the Step 1 product (2.49 mmol) in 20 ml methyl alcohol and 1.5 ml of CHC13 stirred at ambient temperature was treated with a light-protected mixture of silver nitrate (2.64 mmol) and 213 jxl pyridine in 13 ml methyl alcohol. When a precipitate was formed, stirring was stopped and mixture left overnight at ambient temperature. The solid was isolated, then washed twice with 10 ml apiece methyl alcohol and CHC13, and the product isolated. 

Summary The silver salt of NENA is easily prepared by mixing solutions of silver nitrate and ammonium NENA in water. The mixing of the two solutions causes the precipitation of the silver salt of NENA. The precipitate is then filtered-off, washed, and dried. Commercial Industrial note For related, or similar information, see Serial No. 570,806, December 30th, 1944, by The United States Navy, to Alfred T. Blomquist, and Fred T. Fledorek, Ithaca, NY. Part or parts of this laboratory process may be protected by international, and/or commercial/industrial processes. Before using this process to legally manufacture the mentioned explosive, with intent to sell, consult any protected commercial or industrial processes related to, similar to, or additional to, the process discussed in this procedure. This process may be used to legally prepare the mentioned explosive for laboratory, educational, or research purposes. 

Silver carbonyl ferrocyanide, Ag3[Fe(CN)5CO], is obtained as a white curdy precipitate on addition of the potassium salt to silver nitrate solution in the presence of acetic acid.4 It rapidly darkens even when protected from the light. Insoluble in boiling acetic acid, it is slightly soluble in dilute mineral acids evolving hydrogen cyanide. Potassium hydroxide liberates silver oxide, potassium carbonyl ferrocyanide being simultaneously produced. 

Rhenium metal powder is oxidized quantitatively to perrhenic acid by dissolution in 6 M nitric acid followed by repeated evaporation with concentrated nitric acid nearly to dryness. On dilution with 25 ml. of water, neutralization with 6 M sodium hydroxide, and the addition of slightly more than the stoichiometric amount of silver nitrate dissolved in as little water as possible, silver perrhe-nate precipitates in the form of colorless crystals. These additions are made in a beaker protected from light. The solution is decanted from the product, which is dried in an oven at 110° for 8 hours. 

Various theories have been advanced in explanation. Ostwald suggested that supersaturation took place, followed by precipitation, which cleared the immediate neighbourhood of the reactants, and it was therefore necessary for the silver nitrate to diffuse further before supersaturation was again reached. Hatsehek, however, shows that the periodic precipitation takes place in conditions which render supersaturation impossible. Williams and Mackenzie maintain that the silver chromate is precipitated according to the usual rules of the solubility product, and does not behave in any way as a protected colloid but as a crystalloid. More recent w ork suggests that whenever precipitation takes place, the precipitate first passes through the colloidal... 

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