Determination of Ksp, ΔG0, ΔH0, and ΔS0
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[1] University of Rhode Island
University of Rhode Island
Town of South Kingstown, Estados Unidos
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- Localización: Journal of chemical education, ISSN 0021-9584, Vol. 77, Nº 8 (August), 2000, págs. 1039-1039
- Idioma: inglés
- Texto completo no disponible (Saber más ...)
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Resumen
The molar solubility of sparingly soluble calcium hydroxide in water at room temperature and in boiling water is easily determined by titration of filtered saturated solutions with standardized hydrochloric acid solution. The apparent equilibrium constant, Ksp, can be calculated from the molar solubility of calcium hydroxide: Ksp = [Ca2+][OH-]2. The for the dissolution of calcium hydroxide at each temperature is calculated from the formula = -RT ln(Kc). values at two temperatures permit the calculation of and . This exercise utilizes low-cost, relatively nonhazardous materials presenting few disposal problems. It reinforces the students' understanding of the interrelationship of solubility, Ksp, , , and . The significant extent of Ca(OH)2 solubility and its favorable temperature variation provide unique conditions for the success of this experiment.
