Zinc uranyl acetate

The larger cations of Group 1 (K, Rb, Cs) can be precipitated from aqueous solution as white solids by addition of the reagent sodium tetraphenylborate, NaB(C( H5)4. Sodium can be precipitated as the yellow sodium zinc uranium oxide ethanoate (sodium zinc uranyl acetate). NaZn(U02)3(CH3C00)y. 9H2O. by adding a clear solution of zinc uranyl acetate in dilute ethanoic acid to a solution of a sodium salt. 

Sodium, D. of as zinc uranyl acetate, (g) 467 by flame photometry, 812 Sodium arsenite solution prepn. of standard, 390... 

Sodium tungstate 699 Sodium zinc uranyl acetate 467 Sol 419... 

In the indirect polarimetry method [561] sodium is precipitated as the zinc uranyl acetate salt and the uranium present in the precipitate is determined... 

Sparingly Soluble Sodium and Potassium Salts. 1. Add several drops of a zinc uranyl acetate solution to 0.5 ml of a neutral solution of a sodium salt. Note the colour of the precipitate. Write the equation of the reaction., ... 

Uranyl zinc acetate solution Potassium (1), K Yellow precipitate of sodium zinc uranyl acetate sensitivity, 12.5 jag of Na... 

The reagent is prepared as follows. Dissolve 10 g uranyl acetate in 25 ml 30 per cent acetic acid, warming if necessary, and dilute with water to 50 ml (solution a). In a separate vessel stir 30 g zinc acetate with 25 ml 30 per cent acetic acid and dilute with water to 50 ml (solution b). Mix the two solutions a and b, and add a small quantity of sodium chloride. Allow to stand for 24 hours, and filter from the precipitated sodium zinc uranyl acetate. 

Zinc Uranate, ZnU04, is deposited, according to Wertheim, on a sheet of zinc placed in a solution of uranyl nitrate or it may be precipitated from a solution of zinc uranyl acetate by the addition of baryta water. It is an amorphous yellow powder, insoluble in w ater. 

Indirect determinations of several types can be carried out. Sulfate has been determined by adding an excess of standard barium(II) solution and back-titrating the excess. By titrating the cations in moderately soluble precipitates, other ions can be determined indirectly. Thus sodium has been determined by titration of zinc in sodium zinc uranyl acetate, and phosphate by determination of magnesium in magnesium ammonium phosphate. Quantitative formation of tetracyano nickel-ate(II) has been used for the indirect determination of cyanide. ... 

Zinc uranyl acetate (reagent for sodium). Dissolve 10 g of U02(C2Hj,02)2-2H20 in 6 g of 30% acetic acid with heat, if necessary, and dUute to 50 mL. Dissolve 30 g of ZnlCjHjOj) - in 3 g of 30% acetic acid and dUute to 50 mL. Mix the two solutions, add 50 mg of NaCl, allow to stand overnight and filter. 

The methods for measuring impurities in samples should be sensitive. In contrast identification tests should be rather insensitive. For example the flame test for sodium ions will give a positive even with trace amounts present hence the use of the precipitation method with zinc uranyl acetate in pharmacopoeias. 

The isothermal method was used. Solid sodium phosphate was added to saturated solutions of copper phosphate and the mixtures were equilibrated for 8-10 hours. The copper content was determined as CuO. The phosphate content was determined colorlmetrically and the sodium content was determined as sodium zinc uranyl acetate after separation with the aid of an ion exchanger. 

The Limit of Identification of this test is only 3 y potassium, which consequently can be detected directly in the presence of sodium only if not more than 10 times the quantity of the latter is present. Otherwise, sodium dipicrylaminate is salted out. If potassium is to be detected in the presence of greater amounts of sodium, the latter should be removed beforehand as sodium zinc uranyl acetate (see page 428). The filtrate is evaporated to dryness, ignited, and the residue subjected to the test for potassium. 

Sodium is precipitated from neutral or acetic acid solution by an acetic acid solution of zinc uranyl acetate. Yellow, crystalline NaZn(U02)3-(CHgCOO) 9 HgO precipitates. Salts of Cu, Hg, Cd, Co, Ni, Al, Mn, Zn, Ca, Sr, Ba, Mg, and NH4 affect the sensitivity only in concentrations greater than 5 g per liter. Lithium salts are precipitated from solutions containing 1 g per liter and potassium salts from solutions exceeding 5 g per liter. 

Considerably smaller amounts may be detected by utilizing the fact that solid sodium zinc uranyl acetate gives a bright greenish-yellow fluorescence in ultraviolet light, whereas the reagent solution does not fluoresce. ... 

Reagent Solution of zinc uranyl acetate [a) 10 g of uranyl acetate is dissolved by warming in 6 g of 30 % acetic acid, and diluted with water to 50 ml. (6) 30 g zinc acetate is stirred up with 3 g 30 % acetic acid, and diluted with water to 50 ml. Warm suspensions (a) and (5) are mixed and give a clear solution. A trace of sodium chloride is added, and after 24 hours the slight precipitate of sodium zinc uranyl acetate is filtered off and discarded. The reagent keeps. 

Sodium Zinc uranyl acetate Zinc uranyl acetate in ultraviolet 12.5 428... 

Some simple organic reagents. Various triple acetates of Na, used in analysis, are relatively insoluble. Zinc uranyl acetate and neutral, not too dilute, Na" precipitate NaZn(U02)3(CH3C02)9"6H20, yellow and crystalline. The corresponding Mg and Co (not Ca) salts are similar. 

Prepare a concentrated solution of sodium chloride and add to it a solution of magnesium or zinc uranyl acetate. 

Sodium-acetate precipitatea aodium uranyl acetate from neutral or weakly acidic aolutiona of uranyl aalta. The method la not very uaeful for the precipitation of tracea of Uranium. The aolublllty of aodlum uranyl acetate in a aolutlon 5M in aodlum nitrate, IM in acetic acid, and 0.5M in aodlum acetate la about 100 mg per liter.Neptunliuii (Vl) and plutonium (Vl) alao precipitate under theae condl-tiona. The addition of aodlum acetate and zinc acetate to a neutral or weakly acidic uranyl aalt aolutlon precipitatea the triple aalt, aodlum zinc uranyl acetate. 

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