Lead selenites

Chukhlantsev and Tomashevsky [57CHU/TOM] prepared lead selenite by mixing an acidified 0.2 M solution of lead acetate and a 0.1 M sodium selenite solution in stoichiometric amounts. The precipitate was crystalline. Chemical analysis confirmed the 1 1 ratio between Pb(Il) and Se(IV). No X-ray diffraction measurements were performed. The solubility of the specimen in dilute solution of nitric or hydrochloric acid was measured at 293 K. The experiments were performed and the data recalculated as described in Appendix A, [56CHU]. The result for  

Wide uncertainty limits are applied since the experimental information is somewhat meagre. 

The selected result differs from the value in [82WAG/EVA], - 537.6 kJ mol . The causes of the difference are discussed in Appendix A. 

Gospodinov and Bogdanov [89GOS/BOG] determined the melting point of PbSe03(cr) to be (948 5) K and its enthalpy of fusion by differential scanning calorimetry to be  

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Reaction with sodium selenate yields lead selenate, PbSe04. Similarly, with sodium selenite or selenious acid, the product is lead selenite, PbSeOs. 

The enthalpy change of the reaction between Na2Se03(cr) and a lead nitrate solution with formation of crystalline lead selenite was measured in a calorimeter. The data have been used to calculate the standard enthalpy change of the reaction Na2Se03(cr) + Pb PbSe03(cr) + 2Na in Table A-26. 

The value of the standard enthalpy of formation of lead selenite obtained from A // and accepted standard enthalpies of formation is ... 

Klushina, Selivanova, and Poltavtseva prepared crystalline Li2Se03 H20 and measured the enthalpy of the reaction of the salt with a lead nitrate solution in an electrically calibrated calorimeter. Crystalline lead selenite is formed. In the evaluation of the calorimetric measurements the authors divided the heat evolved by the number of moles of Li2Se03 H20 taken. This is incorrect as the amount of Pb(N03)2 used limits the amount of lead selenite that can be formed. The data have been recalculated to find the enthalpy change of the reaction Li2Se03-H20(cr) + Pb PbSe03(cr) + 2Li + H20(l) in Table A-54. 

Sodium hydrogen selenite was prepared and the specimen checked by X-ray and chemical analysis. The enthalpy of reaction between solid NaHSe03 and a solution of lead nitrate with formation of crystalline lead selenite was measured in an electrically calibrated calorimeter. The result is used in Table A-67 to calculate the enthalpy of the reaction NaHSe03(cr) + Pb -> PbSe03(cr) + + Na. ... 

Crystalline sodium trihydrogen selenite was prepared and reacted in stoichiometric proportions with a solution of lead nitrate in an electrically calibrated calorimeter. The lead selenite formed was crystalline and the reaction was quantitative. The calorimetric data have been used to calculate the enthalpy change of the reaction NaH3(Se03)2(cr) + 2Pb 2PbSe03(cr) + Na -i- 3H in Table A-74. 

Sodium diselenite was prepared from NaHSeOs by heating at 383 K. The quality of the specimen was controlled by X-ray and chemical analysis. The salt was reacted with a solution of lead nitrate in an electrically calibrated calorimeter with formation of crystalline lead selenite. The enthalpy change of the reaction Na2Se205(cr) + H20(l) -i-2Pb 2PbSe03(cr) + 2Na + 2H is estimated in Table A-75. 

The result for lead selenite is accepted, but a recalculation with the protonation constants of the selenite ion and the activity coefficient expression selected by the review is not possible. 

SEL/LES3] Selivanova, N. M., Leshchinskaya, Z. L., Physical-chemical properties of selenites. Thermodynamic properties of lead selenite, 7>. Inst.-Mask. Khim.-Tekhnol. Inst. Im. D. 1. Mendeleeva, 38, (1962), 37-42, in Russian. Cited on pages 223, 466. 

BAK/BUK] Bakeeva, S. S., Buketov, E. A., Pashinkin, A. S., Dissociation pressure of lead selenite, Izv. Akad. Nauk SSSR, Neorg. Mater., 1, (1971), 1261-1262, in Russian, English translation in... 

PbSe03 LEAD SELENITE 1308 Pul3 PLUTONIUM TRIIODIDE 1349... 

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