Potassium oxalate hydrate

The isomeric dichloro-chlorides on hydration pass into the diaquo-salts, [Cr en2(H20)2]R3, and by the removal of water from these the corresponding dichloro-chlorides remain. The configuration is established by the behaviour of the salts towards potassium oxalate. The cis-salts react easily with potassium oxalate, giving the oxalato-deriva-tive, [Cr ensC204]R, whereas trans-salts are not acted upon by the oxalate. Further, the oxalato-salt formed gives, on treatment with... 

The moist gel is added to a mixture of 23 6g of oxalic acid 2-hydrate and 34.5g of potassium oxalate monohydrate in 100ml of hot water. Hie solution is filtered, if necessary, and evaporated to crystallization on the steam bath. The product is filtered off and dried in the dark. The mother liquor yields small additional amounts of product... 

The preparation of potassium tetraoxalatothorate 4-hydrate is based on the observation of Cleve that insoluble thoriiun oxalate dissolves in boiling potassium oxalate solution under unspecified concentration conditions. 

A mixture of 20.0 g. (0.08 mol) of cobalt(II) acetate 4-hydrate, 50.0 g. (0.27 mol) of potassium oxalate 1-hydrate, and 0.5 ml. of glacial acetic acid in 150 ml. of water is placed in a beaker protected from light and is stirred mechanically and heated to 55°, whereupon a clear solution results. Sixty milliliters of 6% hydrogen peroxide is added dropwise from a buret over a 15-minute interval. The temperature is kept at 55 to 56° by the addition of small pieces of ice as the reaction proceeds. The dark green product is filtered off at room temperature, washed well with ice water, methanol, and finally acetone, and dried in the dark at 40° yield, 27.1 g. (94%). Anal. Calcd. for K4[Co2(C204)4(OH)2]-3H20 C, 13.45 H, 1.12. Found C, 13.44 H, 1.05. 

The cases listed in Tables 7 and 19 give general support to this idea. We may also draw attention to three cases where failure to make use of crystal symmetry (which would be chemically feasible) is associated with hydrogen bonds that are significantly longer than those in Type A structures sodium bicarbonate (Sect. XV), potassium hydrogen oxalate (XVI B) and sodium hydrogen oxalate hydrate (XVI C). 

It ia usually met with in cylindrical sticks, hard, white, opaque, and brittle. The KHO by alcohol has a bluiali tinge and a smoother surface than the common ep. gr. 2.1 fuses at dull redness is freely soluble in H,0, forming a strongly alkaline and caustic liquid less soluble in alcohol. In air, solid or in solution, it absorbs H,0 and CO, and is converted into K,CO,. Its solutions dissolve Cl, Br, 1, S, and P. It decomposes the am-moniaic salts with liberation of NH, and the salts of many of the metals, with formation of a K salt and a metallic hydrate. It dissolves the albuminoids and, when heated, decomposes them with formation of leucin, tyroein, etc. It oxidizes the carbohydrates with formation of potassium oxalate and carbonate. 

A variety of methods (65, 228, 434) have been used to prepare soluble tetraoxalato salts. A suitable synthesis for potassium tetraxoalato-zirconate(hafnate) 267) free of hydroxy species is one in which a zirconium (hafnium) oxychloride solution is added to a buffered solution containing a stoichiometric amount of potassium oxalate and half the amount of oxalic acid. The potassium tetraoxalatometallate penta-hydrate is then precipitated upon slow addition of ethanol. 

Potassium tetraoxalatouranate(IV) 5-hydrate has been prepared by the reaction of a potassium oxalate solution with an excess of uranium(IV) oxalate 6-hydrate.This excess prevents contamination of the product by potassium oxalate, since both potassium tetraoxalatouranate(IV) and potassium oxalate are precipitated from aqueous solution by absolute alcohol. 

A solution of 5 g. (0.027 mol) of potassium oxalate 1-hydrate in 20 ml. of water is added to a slurry of 6 g. (0.014 mol) of uranium(IV) oxalate 6-hydrate in 50 ml. of water. The reaction is complete after the mixture has been heated on a steam bath for 1 hour. The dark green filtrate is treated with 200 ml. of absolute alcohol, which is added drop by drop from a separatory funnel while the mixture is stirred. J Small light green crystals are obtained, which are quickly dried by washing them several times with absolute alcohol and finally with ether. To avoid oxidation, potassium tetraoxalatouranate(IV) is stored in a desiccator over phosphorus (V) oxide. 

The anhydrous alkali double carbonates of the rare earths have been synthesized from mixtures of M2CO3 (M = Li, Na, K) and rare earth oxalate hydrate under carbon dioxide pressure of 200-300 MPa and at temperatures of 350-500°C (fig. 26). The sodium and potassium compounds can also be synthesized by dehydration of MR(C03)2 H20 under the same experimental conditions. At lower pressures (20 MPa) litliium forms an oxycarbonate, LiROC03 (Kalz and Seidel, 1980). The compounds have been characterized from powder samples by IR and X-ray investigations and by thermal decomposition studies. 

C10H2 oCuOi0 f Bis(methanol)tetraacetatodicopper(II), 45B, 1112 CioH2oKe03aU2, Potassium uranyl oxalate hydrate, 42B, 784 CloH2aCuN20i0, Bis(2-hydroxyethyliminopyruvato)copper(II) tetrahydrate, 34B, 529... 

Chromium(lll) potassium oxalate tri hydrate K3Cr(C303)3-3H30 16276-09-9 487.394 blue-grn monoci cry sH,0... 

This complex is prepared by reducing the alkali vanadate (formed from the ammonium salt) by hydrazine hydrate in acetic acid. The addition of potassium oxalate in presence of ethanol precipitates the complex. 

Crystallizes from water in large colourless prisms containing 2H2O. It is poisonous, causing paralysis of the nervous system m.p. 101 C (hydrate), 189°C (anhydrous), sublimes 157°C. It occurs as the free acid in beet leaves, and as potassium hydrogen oxalate in wood sorrel and rhubarb. Commercially, oxalic acid is made from sodium methanoate. This is obtained from anhydrous NaOH with CO at 150-200°C and 7-10 atm. At lower pressure sodium oxalate formed from the sodium salt the acid is readily liberated by sulphuric acid. Oxalic acid is also obtained as a by-product in the manufacture of citric acid and by the oxidation of carbohydrates with nitric acid in presence of V2O5. 

Extended refluxing of hydrated RhCl3 with excess oxalate leads to the tris complex, the potassium salt crystallizing as orange-red crystals with Rh-O 2.000-2.046 A. 

Malonic acid has been made by the hydrolysis of malononitrile with concentrated hydrochloric acid,2 by the hydration of carbon suboxide,3 and by the hydrolysis of cyanoacetic acid4 and its esters5 with potash. A method for the preparation of calcium malonate from chloroacetic acid and potassium cyanide is described by Fischer.6 Conrad7 liberated malonic acid from calcium malonate, so prepared, with oxalic acid. v. Miller,8 Grimaux and Tscherniak, and Bourgoin10 prepared malonic acid from chloroacetic acid and potassium cyanide, Petriev11 from... 

In a 1-1., round-bottomed flask is placed 72 g. of the crude oxazolidine in 600 ml. of water, and 201.6 g. (1.6 moles) of hydrated oxalic acid is added. The mixture is then heated under reflux for 1 hour, cooled, treated with 600 ml. of water to dissolve precipitated oxalic acid, and extracted with three 100-ml. portions of ether. The combined ethereal extracts are washed with 50 ml. saturated sodium bicarbonate solution and then dried over anhydrous potassium carbonate. Concentration of the ethereal solution gives 30-35 g. of crude aldehyde. Distillation of this material at 70-75° (1.5 mm.) gives pure o-anisaldehyde (22.8—26.3 g. 51-59%), m.p. 35.5-38° (Note 9). 

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