The solubility of Ca(OH)(2) in extremely concentrated NaOH solutions at 25A degrees C

作者：Pallagi Attila^*; Tasi Agost; Gacsi Attila; Csati Miklos; Palinko Istvan; Peintler Gabor; Sipos Pal

来源：Central European Journal of Chemistry, 2012, 10(2): 332-337.

DOI：10.2478/s11532-011-0145-0

• Solubility apparatus
• Solubility
• ICP AES
• Ca(OH)2
• Concentrated electrolytes
• Aqueous solutions

The solubility of Ca(OH)(2) in aqueous NaOH solutions up to 12.50 M at 25A degrees C has been determined. The solubility data obtained for NaOH concentrations lower than 3 M was compared with those published in the literature. The solubility of Ca(OH)(2) steadily decreases with the increasing NaOH concentration. The solubility data obtained at a constant ionic strength (I = 1 M Na(Cl,OH)) enabled the determination of the conditional solubility product of Ca(OH)(2)(s) (lgL(Ca(OH)2) = - 4.10 +/- 0.02). Formation of the hydroxo complex CaOH+(aq) was invoked to describe the variation of [Ca2+](T) with [OH-](T). Its conditional stability constant was found to be lgK(CaOH+) = 0.97 +/- 0.02. The experimental protocol employed was proven to be suitable for accurate solubility determinations in rapidly equilibrating systems comprising of highly concentrated, alkaline solutions and containing analytes in the ppm range.

• 出版日期2012-4