Ammonium solution

Preparation of tantalum and niobium oxides based on the precipitation by ammonium solution of tantalum or niobium hydroxides from strip solutions is the most frequently used method in the industry and consists of several steps. Fig. 135 presents a flow chart of the process. 

Based on the above approach, the phases that are obtained from the strip solutions by precipitation with ammonium solution can be represented by the general formula xNH4F-yMe2C>5-zH20 or by the following interaction ... 

Blood Dilution of sample with ammonium solution containing Triton X-100 ICP/MS 15 pg/L 96-111 Delves and Campbell 1988... 

Shriadah and Ohzeki [350] determined iron in seawater by densitometry after enrichment as a bathophenanthroline disulfonate complex on a thin layer of anion exchange resin. Seawater samples (50 ml) containing iron (II) and iron (III) were diluted to 150 ml with water, followed by sequential addition of 20% hydrochloric acid (100 xl), 10% hydroxyl-ammonium chloride (2 ml), 5 M ammonium solution (to pH 3.0 for iron (III) reduction), bathophenanthroline disulfonate solution (1.0 ml), and 10% sodium acetate solution (2.0 ml) to give a mixture with a final pH of 4.5. A macroreticular anion exchange resin in the... 

Procedure Pipette 25 ml of a standard 0.1 N AgN03 solution into a glass-stoppered flask (iodine-flask), dilute with 50 ml of DW, add to it 2 ml of nitric acid and 2 ml of ferric ammonium sulphate solution and titrate with ammonium solution to the first appearance of red-brown colour. Each ml of 0.1 N silver nitrate is equivalent to 0.007612 g of NH4SCN. 

Cobalt and Nickel Ammines. First add a little, and then an excess of a concentrated ammonia solution to solutions of cobalt(II) and nickel(II) salts. What do you observe Boil the ammonium solution of the cobalt salt while shaking the test tube (for what purpose ). Explain the changes in its colour. Write the equations of the reactions. 

Ammonium, Metal(Metal Ammonium). Solutions of mercury arid the alkali metals in liq ammonia were first prepd and studied by Weyl (Ref 1). According to his views, the metals are joined to the nitrogen of ammonia, forming substituted ammonium radicals. Many investigators later studied the solns of metals in liq ammonia and while a few of the investigators were in favor of Weyl s theory(Joannis in 1892, Moissan in 1898 and Benoit in 1923), others were against it(Seeley in 1871, Ruff and Geisel in 1906, Kraus in 1908, Biltz in 1920 etc)... 

To examine the response time to NH4+, ammonium solutions were dropped on this optode membrane, and then the time-course dependence of the Qx and Qy values was monitored. As a result, within 10 s the Qx and Qy values became saturated. 

To a suspension of 1 part chloroacetyl chloride and benzcatechole, see J. Russ. Phys. Chem. Ges., 25, 154) was added dropwise 1 part 60% solution of methylamine. Immediately was formed a residue of the salt of methylamine and (n-chloro-3,4-dihydroxyacetophenone. The dissolution of the salt was carried out by heating of the mixture. Then the salt was converted in crude 3,4-dihydroxy-a-methylaminoacetophenone. The product was dissolved in dilute hydrochloric acid. To this solution was added dropwise aqueous ammonium solution to prepare light yellow crystal of 3,4-dihydroxy-a-methylaminoacetophenone. 

To a solution of 22.7 g of quinone monoguanylhydrazone nitrate in 250 ml water is added dropwise hot aqueous solution of 9.1 g thiosemicarbazide, then is added slowly a solution of 5 ml concentrated nitric acid in 10 ml of water. The mixture is stirred at 60°C for 1 hour. The product is dissolved in 1-1.2 L of water at 100°C. The solution is filtered and added to an aqueous ammonium solution. Blue residue of p-benzoquinone amidinohydrazone thiosemicarbazone is filtered and dried, melting point 188°C (decomp.). 

Viscose rayon is but one variety of rayon, a more general term for derivatized or reconstituted cellulose. Other rayons include fiber prepared from collodion, cellulose acetate, and cellulose fiber regenerated from a cellulose-copper ammonium solution cuprammonium rayon) (Kauffman 1993). 

By combining results of Mossbauer and EXAFS spectroscopies we are able to draw certain conclusions about the iron sites in the chabazite samples. Considering first the iron in the Na,K(Fe) chabazite, we find that the iron is not exchangable with the ammonium solutions used, indicating that the iron is either in an inaccessible site, is incorporated into the zeolite framework, or is present as species insoluble under exchange conditions used in the zeolite. The Mossbauer spectra tell us that all of the iron in the zeolite is in nearly identical environments, so only one of the above options is possible. 

Ammonium solution white gelatinous precipitate of aluminium hydroxide, Al(OH)3, slightly soluble in excess of the reagent. The solubility is decreased in the presence of ammonium salts owing to the common ion effect (Section 1.27). 

Dissolve 100 grams of 2,4,6-trinitrotoluene into 200 milliliters of p-dioxane, and then place the mixture into a cold-water bath. Then stir the mixture, and add 2 milliliters of 28 - 30% ammonium solution. Then bubble 46 grams of hydrogen sulfide gas into the mixture over a 2-hour period while keeping the reaction temperature at 20 Celsius by means of the cold-water bath, and stir the reaction mixture continuously during the addition. After the addition of the hydrogen sulfide gas, filter off the precipitated sulfur, and then add the filtered reaction mixture to 1000 milliliters of ice water. After which, filter off the yellow precipitated solid, and then wash the solid with 400 milliliters of water. Then vacuum dry or air-dry the solid. The result is a mixture of the desired 4-amino-2,6-dinitrotoluene (61%), and the by-product, 4-hydroxylamino-2,6-dinitrotoluene (39%). 

Procedure Add and dissolve 20 milliliters of 28 to 30% ammonium solution into 400 milliliters of water. Thereafter, add 20 grams of styphnic acid, and stir the mixture vigorously for about 20 minutes (at the end of 20 minutes, a clear solution will result). Then, heat the mixture to 80 Celsius. While the mixture begins to heat-up to 80 Celsius, prepare a solution by adding and dissolving 20 grams of barium chloride dihydrate into 150 milliliters of water. When the styphnic acid mixture reaches about 80 Celsius, add the barium chloride dihydrate solution over a period of about 4 minutes while constantly stirring the styphnic acid mixture. Note a yellow precipitate will form immediately after the first addition of the barium chloride dihydrate. After the addition of the barium chloride dihydrate solution, remove the heat source and allow the reaction mixture to cool to room temperature. Then place the reaction mixture into a cold-water bath for 30 minutes. Afterwards, filter-off the precipitated product, wash with 200 milliliters of water, 100 milliliters of acetone, and then vacuum dry or air-dry the product. The result will be a yellow solid with very uniform particle size. 

The use of a series of mixer/settlers, operating in countercurrent flow, between -20 and +5 C, at OJ to 0.4.10 Pa, to absorb the butadiene and to achieve the progressive enrichment of the ammonium solution by liquid/liquid contact. Butadiene desorption by heating around 80°C at 0.12.10 Pa. 

Low temperature synthesis of lead zirconate titanate (PZT) can also be obtained via a microemulsion process [161]. The microemulsion, containing cations of lead zirconium and titanium in the aqueous phase, was coprecipitated as hydroxide precursors by the addition of ammonium solution. Crystalhne tetragonal PZT powders were then obtained by calcining the precursors at a temperature as low as 450 °C in air without forming any intermediate phases. 

The 2-mercapto derivatives 533 were desulfurized by heating in aqueous ammonium solution in the presence of Raney nickel to yield 2-unsubstituted pyrimido[4,5-d]azepines 534 in 85% yield (71BCJ153). 

The data for TUB hydroxide solubility in different media have recently receive a great deal of attention due to their importance for development of clean-up technologies, etc. It is known that the Pu(OH)3 solubility in water and 5M ammonium solution is equal to 7.5 10 M and 3.8 10 " M, respectively [12]. The solubility product of the Pu(III) hydroxide is about 2 10 ° [13,14]. According to the data of different authors, the solubility products of Pu(OH)3 and Am(OH)3 hydroxides are equal to about 10 [15]. The solubility of Pu(III) hydroxide in 5M NH4OH is 3.8 10"" M [16], and the solubility of Am(III) in 0.01-5M NH4OH is 1.6 10" M [17]. The suggested chemical form of these alkali-dissolved hydroxides is a neutral Am(OH)3-type molecule, which does not tend to have an amphoteric nature or to form complexes with OH" ions. Despite the low solubility of TUE(III) hydroxides, in the crystalline form they can be easily dissolved. Thus, the concentration of the Am(OH)3 and Cm(OH)3 colloid solutions may exceed more than 100 g/L [4]. 

Urine (total) Digestion with HN03/HCI03 and heat evaporation addition of NH4CI/ammonium solution dilution with water ASV NR 100-105 Liu et al. 1990... 

Figure 11. Polarization curves for silver electrodeposition from the nitrate solution on (a) a graphite electrode previously plated with silver from the ammonium solution (b) on an uncovered graphite electrode. Reprinted from ref.7 with permission from Elsevier.

Figure 13. The silver layer on a graphite electrode obtained by electrodeposition from the ammonium solution at an overpotential of 100 mV for (a) 2.5 s. The current density on this electrode in the ammonium solution at an overpotential of 30mV was 0.5mAcm-2. Magnification 3,500x (b) 60s. The current density on this electrode in the ammonium solution at an overpotential of 30 mV was 1.0mAcm 2. The current density on a completely covered graphite electrode after a pulse of an overpotential of 150 mV for 3 s and deposition at an overpotential of 100 mV for 10 min was 1.25 mA cm-2 at the same potential. Magnification 1,000 x. Reprinted from ref.7 with permission from Elsevier.

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