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The kinetics of the thermal dehydration of compacted composite grains of Na2CO3∙H2O (SC-MH) comprising columnar SC-MH crystalline particles and an SC-MH matrix were investigated as a model system for composites...

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The thermal dehydration of calcium sulfate dihydrate exhibits complex reaction behavior, in which the reaction pathway and kinetics vary depending on water vapor pressure (p(H2O)) applied as the atmospheric condition...

This study aims to identify the kinetic features of individual reaction steps of the multistep thermal dehydration of calcium sulfate dihydrate (CS-DH) to anhydride via hemihydrate (CS-HH) intermediate by achieving...

The effect of atmospheric water vapor on the thermal dehydration of sodium carbonate monohydrate (SC-MH), which is characterized as cubic grains of a compacted composite comprising columnar SC-MH crystals and...

In this laboratory experiment, a guided inquiry exploring the physicochemical principles of the dissolution of Ca(OH)2(s) in water is proposed for laboratory classes in university and high school. As part of students’ inquiry, two experimental approaches are used. One is the change in solubility with temperature revealed by measuring the pH values of the suspended solution of Ca(OH)2(s) at various temperatures, which is then extended to its thermodynamic relationship via examining the temperature dependence of the solubility constant. The other method is to determine the enthalpy of solution using the calorimetric measurements. Due to the poor solubility of Ca(OH)2(s), for determining the enthalpy of the Ca(OH)2(s) solution, development of an energy diagram composed of several paths of a reaction that involve the dissolution of Ca(OH)2(s) as a component process and using Hess’s law are essential. A combination of these experimental approaches yields a stepwise students’ inquiry for revealing the source of the changes in Ca(OH)2(s) solubility with temperature, which may be flexibly adapted as an appropriate program depending on the targeted students. The two experimental procedures are presented by critically examining the experimental results. Based on the results of educational practices, typical guided inquiry constructions suited for the university and high school chemistry courses are proposed.