Barium oxalate

The reactor has been successfully used in the case of forced precipitation of copper and calcium oxalates (Jongen etal., 1996 Vacassy etal., 1998 Donnet etal., 1999), calcium carbonate (Vacassy etal., 1998) and mixed yttrium-barium oxalates (Jongen etal., 1999). This process is also well adapted for studying the effects of the mixing conditions on the chemical selectivity in precipitation (Donnet etal., 2000). When using forced precipitation, the mixing step is of key importance (Schenk etal., 2001), since it affects the initial supersaturation level and hence the nucleation kinetics. A typical micromixer is shown in Figure 8.35. 

Jongen, N., Lemaitre, J., Bowen, P. and Hofmann, H., 1999. Aqueous synthesis of mixed yttrium-barium oxalates. Chemistry of Materials, 11, pp. 712-718. 

Kasuganobiosamine (4) by Hot Alkaline Hydrolysis. An aqueous solution (150 ml.) saturated with barium hydroxide was added to a solution of kasugamycin hydrochloride (5.3 grams, 12.22 mmoles) dissolved in 50 ml. of water free from carbon dioxide. The solution was refluxed on a steam bath for 10 hours. By the similar treatment of the reaction mixture as described in the case of cold alkaline hydrolysis, ammonia (11.10 mmoles), barium oxalate (3.037 grams, 12.48 mmoles) and kasuganobiosamine (3.638 grams, 11.80 mmoles) were obtained. 

Kasuganobiosamine (4) and Kasugamycinic Acid (9a) by cold Alkaline Hydrolysis. Kasugamycin hydrochloride (622 mg., 1.43 mmoles) was dissolved in 5 ml. of water free from carbon dioxide and 50 ml. of water saturated with barium hydroxide was added. The solution was allowed to stand at room temperature for 36 hours. Ammonia (0.30 mmole) was produced and barium oxalate (199 mg., 0.80 mmole) was obtained. After removal of barium oxalate by filtering, the filtrate was neutralized with dry ice. After removal of barium carbonate by filtering, the filtrate was adjusted to pH 7.0 and placed on a column of Amberlite CG-50 (ammonium form, 1.5 x 22 cm.), allowed to pass with a rate of... 

Alkaline Hydrolysis of Kasugamycinic Acid (9a) with Barium Hydroxide. Kasugamycinic acid (250 mg., 0.63 mmole) was hydrolyzed with barium hydroxide-saturated-water at 100°C. for 10 hours, and the reaction mixture was treated in the similar manner as described in the case of alkaline hydrolysis of kasugamycin, affording kasuganobiosamine (4) (179 mg., 0.68 mmole) and barium oxalate (151 mg., 0.62 mmole). 

The requirements of the US Armed Forces are contained in Mil Spec JAN-B-660, Barium Oxalate (For Use In Ammunition) , (5 Aug. 1948) Color — white moisture — 0.3% max material insol in 10% HC1 soln - 0.5% max material sol in water - 0.3% max water sol alkalinity — 0.1% max water sol acidity — the water extract shall not be acid to methyl orange barium oxalate — 92% min calcium salts —... 

Barium acetate converts to barium carbonate when heated in air at elevated temperatures. Reaction with sulfuric acid gives harium sulfate with hydrochloric acid and nitric acid, the chloride and nitrate salts are obtained after evaporation of the solutions. It undergoes double decomposition reactions with salts of several metals. For example, it forms ferrous acetate when treated with ferrous sulfate solution and mercurous acetate when mixed with mercurous nitrate solution acidified with nitric acid. It reacts with oxahc acid forming barium oxalate. 

Azidoethyl Barium carbonate Barium chlorate Barium nitrate Barium oxalate Barium styphnate BBC... 

Preparation of Potassium Trioxalatoferrate(III). First prepare barium oxalate. To do this, add a solution of 2.5 g of barium chloride dihydrate in 6 ml of water to a solution of 1.5 g of sodium oxalate in 40 ml of water. Filter off the formed crystals on a Buchner funnel and wash them several times with cold water. 

To prepare potassium trioxalatoferrate(III), put 1.25 g of iron(III) sulphate, the prepared barium oxalate, 1.5 g of potassium oxalate, and 30 ml of water into a 500-ml beaker. Heat the mixture for several hours in a water bath, maintaining a constant volume. After separation of the barium sulphate precipitate, evaporate the filtrate to a volume of 5 ml and cool it. Filter off the potassium trioxalato-ferrate(III) crystals, rinse them with a small amount of water and then with ethanol, and dry them in a vacuum-desiccator over sulphuric acid. Write the equations of the reactions. 

Finding the concentrations of species in saturated barium oxalate solution ... 

Results in Figure 13-12 show that the solubility of barium oxalate is steady at 10 3 M in the middle pH range. Solubility increases below pH 5 because C20 reacts with H+ to make HC2Oj. Solubility increases above pH 13 because Ba2+ reacts with OH to make BaOH+. 

We considered solubility problems in which the cation and anion could each undergo one or more acid-base reactions and in which ion pairing could occur. Substitute fractional composition expressions for all acid-base species into the mass balance. In some systems, such as barium oxalate, the resulting equation contains the formal concentrations of anion and cation and [H+]. The solubility product provides a relation between the formal concentrations of anion and cation, so you can eliminate one of them from the mass... 

Barium Oxalo-niobate, 5BaO.Nb2Os.10C2O3.20H2O, does not belong to the alkali series described above. It is prepared either by the addition of barium chloride to a solution of potassium oxalo-niobate, or by digestion of a mixture of barium oxalate and hydrated niobium pentoxide in a solution of oxalic acid. The crystals are soluble in oxalic acid solution but insoluble in water and in cold hydrochloric and nitric acids. 

Barium oxalate, [CAS 516-02-9], BaC20,, white precipitate, K3p = 1.1 x 10-7, formed by reaction of barium salt solution and ammonium oxalate solution. 

Twenty-five grams of ferric sulfate, 50 g. of barium oxalate (which may be prepared from 50 g. of BaCl2 2H20 and 29.3 g. of Na2C204), and 27.3 g. of potassium oxalate monohydrate are placed in 600 ml. of water and digested for several hours on the steam bath. After filtering with suction and washing the precipitate, the filtrate is evapo-... 

Any soluble ferric salt, in the presence of excess oxalate ion, yields the trioxalatoferriate. By using ferric sulfate and barium oxalate the elimination of foreign ions is rendered very easy. 

White precipitate of barium carbonate soluble in dilute acids White precipitate of barium oxalate soluble in dilute acids Heavy, white, finely divided precipitate of barium sulfate White precipitate of barium sulfate... 

Ammonium oxalate solution white precipitate of barium oxalate Ba(COO)2, slightly soluble in water (0 09 g per litre Ks = 1-7x10" 7), but readily dissolved... 

Calcium chloride solution white, crystalline precipitate of calcium oxalate from neutral solutions, insoluble in dilute acetic acid, oxalic acid, and in ammonium oxalate solution, but soluble in dilute hydrochloric acid and in dilute nitric acid. It is the most insoluble of all oxalates (0 0067 g t 1 at 13°) and is even precipitated by calcium sulphate solution and acetic acid. Barium chloride solution similarly gives a white precipitate of barium oxalate sparingly soluble in water (0 016 g t-1 at 8°), but soluble in solutions of acetic and of oxalic acids. 

AIF3H603 aluminum fluoride trihydrate 15098-87-0 25 00 1.9140 1 430 BaC2H205 barium oxalate monohydrate 13463-22-4 25.00 2.6600 1... 

Despite some crystallographic similarities with the acid salt (see below), the water molecules in barium oxalate dihydrate are accommodated differently in the lattice [140]. The extent of water loss from BaC204.2H20 varied with pQi20). The products were the anhydrous salt below 4 Torr, the hemihydrate between 4 and 100 Torr, and the monohydrate above 100 Torr. The rate of water evolution at 353 K exhibited Smith-Topley behaviour and the changes in rate occur at values of pQyD) (5 and 100 Torr) which are close to those characteristic of the stabihty range of the hemihydrate. 

The kinetics of reactions of calcium, strontium and barium oxalates have been studied in less detail than might have been anticipated, particularly in view of the extensive use of calcium oxalate monohydrate as a standard in thermal analysis. 

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