Copper selenite

COPPER CYANIDE COPPER CYANIDE COPPER SELENATE COPPER SELENITE... 

The crystal structures of a handful of ternary anhydrous selenites are known, and NaLa(Se03)2 and NaY(Se03)2,230 containing additional Na+ ions, the copper phases M2Cu(Se03)4 (M=La-Tb)231,232 and the lithium selenite Li3-Lu5(Se03)9233 should be mentioned. The copper selenites show the M3+ ions in... 

Copper sulphate solution bluish-green, crystalline precipitate of copper selenite, CuSe03, in neutral solution (difference from selenate). The precipitate is soluble in dilute acetic acid. 

Chukhlantsev [56CHU] prepared copper selenite by mixing 0.1 M solutions of copper sulphate and sodium selenite in the cold. The product was aged for 24 hours. Chemical analysis confirmed the 1 1 ratio between Cu(ll) and Se(lV). The solubility of the specimen in dilute solution of nitric or sulphuric acid was measured at 293 K. No X-ray diffraction measurements were performed and the solubility equilibrium will be written on the assumption that the composition of the solid phase is CuSe03-2H20 ... 

Ripan and Vericeanu [68R1P/VER] studied the solubility of CuSe03-2H20(s) by conductivity measurements as described in Appendix A. An equilibrium analysis performed as outlined there on the total concentrations provided in the paper, about 1.8 X 10 M, leads to the conclusion that almost 80% of the copper(II) would be present as hydroxo complexes at equilibrium. Hence, a conductivity measurement is unsuitable for the determination of the solubility of copper selenite and no reliable value of the solubility product can be calculated from the data in [68R1PA ER]. Masson et al. [86MAS/LUT] calculated log (, = - (7.49 0.10) from the data neglecting hydrolysis of Cu. ... 

Feroci et al. [97FER/F1N] studied the system Cu -SeOj by polarography. No shift in /2, but a steady decrease in the limiting current, was observed with increasing selenite concentration. It was assumed from these results that solid copper selenite was formed, although no precipitate was observed in the electrode vessel. The solubility product was reported as log Al, ((V. 106), 0.15 M NaNOa, K) = - 8.42. As discussed in Appendix A, the result of this investigation can not be considered as reliable. 

Slavtscheva, Popova, and Gospodinov [93SLA/POP] determined the solubility of copper selenite in dilute nitric acid and calculated its solubility product from measurements of pH and total Cu(ll) concentration in the equilibrium solution. No primary... 

Thermal analysis [820JK/G0S], [84GOS/BOG] indicates that under equilibrium conditions the dissociation of copper selenite would follow the scheme ... 

The authors reacted Na2Se03(cr) with a copper sulphate solution in an electrically calibrated calorimeter and measured the enthalpy change of the reaction. The product was CuSe03-2H20(cr) as shown by chemical analysis and X-ray diffraction. Crystalline anhydrous copper selenite was also prepared and the integral enthalpies of dissolution of the two selenites in 8% HMO3 (HNO3, aq 1 40, and denoted sin below) were determined. The data have been used in Table A-45 to calculate standard enthalpies of formation of the copper selenites. 

MAK/RAT] Makatun, V. N., Rat kovskii, I. A., Pechkovskii, V. V., The dissociation pressures of neutral and basic copper selenites, Zh. Fiz. Khim., 45, (1971), 1591, in Russian, English translation in [71MAK/RAT2]. Cited on page 294. 

CAM/GRA] Campostrini, 1., Gramaccioli, C. M., Demartin, F., Orlandiite, Pb3Cl4(Se03).H20, a new mineral species, and an associated lead-copper selenite chloride from the Baccu Locci mine, Sardinia, Italy, Can. Mineral., 37, (1999), 1493-1498. Cited on pages 636, 637. 

CuSe03 COPPER SELENITE 633 FeBr3 IRON TRIBROMIDE 681... 

Lu5(8e03)9 should be mentioned. The copper selenites show the ions in... 

Fig. 20. Perspective view of the crystal structure of the copper selenites CuR2(Se03)4 (R = La, Nd-Tb) along [010].

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