"Just as a big truck creates a 'whoosh' all around when it passes by, will Toutatis create one as well (like a swoosh or a 'wind')?"
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Experimental determination of the partial molal heat capacities and volumes of aqueous organic compounds
PI: Schulte, Mitchell
Studies of chemical processes leading to the origin of life are aided by geochemical models that involve reactions of aqueous organic mixtures. In turn, these models require accurate values of the thermodynamic properties of these compounds as a function of temperature and pressure. Currently, these model calculations depend largely on extrapolated or estimated values of the thermodynamic properties from a sparse experimental database, mostly at low temperatures.
Model calculations also illustrate the biochemical pathways used by microorganisms that live at conditions on the Earth that are considered extreme. These environmental conditions include elevated temperatures and pressures, very low (or high) values of pH, and metabolism of unusual chemical compounds. The presence of these organisms has led many to speculate that similar organisms may exist or have existed on extraterrestrial objects such as Mars or Europa.
We propose to determine experimentally the thermodynamic properties of aqueous organic compounds at elevated temperatures and pressures. Specifically, we will measure the partial molal heat capacities of aqueous organic compounds as a function of temperature. Our initial efforts will be directed at a number of simple organic compounds that may be considered as precursors to biomolecules (in particular, thiols and organic sulfides) and several important biomolecules (coenzyme M, cysteine, ATP, adenosine). These data will provide direct tests of the estimation methods currently used in theoretical geochemistry to estimate thermodynamic properties. The data will also aid in developing new methods to predict thermodynamic properties for aqueous organic mixtures and help to refine the equations used to calculate reaction properties away from the standard state conditions of 25 C and 1 bar. Lastly, these data are necessary for realistic geochemical models of extreme environments on the Earth, the early Earth and solar system bodies such as Mars and Europa.
