Solid properties, laboratory experiments

A laboratory experiment on colligative properties directs students to determine the molar mass of an unknown solid. Each student receives 1.00 g of solute, 225 mL of solvent and information that may be pertinent to the unknown. 

The book consists of four chapters. The first one deals with the individual components of the studied systems the solid, the solution, and the interface. Solid means rocks and soils, namely, the main mineral and other solid components. In order that the solid/liquid interactions become possible, these must be located in the Earth s crust where groundwater is present. The liquid phase refers to soil solutions and groundwater, and also any solutions that are part of laboratory experiments studying interfacial properties with the objective of understanding the principles behind the reactions. In Chapter 1, the characteristics and thermodynamics of the... 

In addition, the maximum concentrations measured in laboratory experiments and the solubility-limiting solid phases identified are often not in agreement with the results of theoretical thermodynamic calculations. This discrepancy could be due to differences in the identity or the crystallinity of solubility-limiting solids assumed in the calculation or to errors in the thermodynamic property values used in the calculations. Thus, although theorehcal thermodynamic calculations are useful in summarizing available information and in performing sensitivity analyses, it is important also to review the results of empirical experimental studies in site-specific solutions. 

Many studies that have investigated the effects of different geochemical properties on adsorption of As species have used controlled laboratory experiments to evaluate adsorption of As by pure mineral phases such as Fe, Al, and Mn oxides, and clay minerals. Since these mineral phases are often components of aquifer solids, the data from such experiments can be used to help interpret the behavior of As in groundwater. Such an approach has commonly been used to assess As adsorption by soils and lacustrine sediments (Belzile and Tessier, 1990 Bowell, 1994 Fordham and Norrish, 1979 Jacobs et al., 1970). 

It is generally possible to measure the dissolution rate of the solid reactant in a laboratory experiment. In principle, the dissolution time is not a scale-dependent property, as long as the hydrodynamics that determine the mass transfer are... 

These reactions have been reported to occur in the gas and solution phases in laboratory experiments, albeit at conditions not encountered in basin environments. The kinetics and products of decarboxylation of aliphatic, monocarboxylic acids have been shown to depend on the nature of the solid surface present (Palmer and Drummond 1986 Bell 1991 Bell et al. 1993). In fact, decarboxylation of these acids is used as a probe for the catalytic properties of metals and metal oxides (Rajadurai 1987 Kim and Barteau 1988). 

In addition to the activity documented above there has been a tremendous amount of activity in the development of more traditional experiments for the physical chemistry laboratory. Some of these experiments are improvements on older methods, some involve new systems, and some involve new types of analysis. There are far too many of these experiments to discuss individually, but all of them will be found listed in tables below. They have been divided roughly into spectroscopy and the electronic structure of matter, thermodynamics, including thermochemistry and properties of liquids, solids and solutions, and kinetics, including photochemistry. 

Because of the wide field of industrial applications, the need exists to develop simple and reliable techniques for the characterization of solids behavior in the presence of dense gases. From our experience we know that information on sorption equilibria or solubilities of gases in solids, on mass-transfer kinetics, and on volume changes are the most relevant in process design. We have therefore developed experimental methods to obtain these properties through laboratory testwork. 

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