Water; has unusual exotic features (Introduction)

by David Turell , Monday, December 16, 2019, 01:04 (1595 days ago) @ David Turell

Another review of water's many properties:

https://inference-review.com/letter/unresolved-anomalies

"Water’s uniqueness is apparent in its pressure-temperature phase diagram, which, particularly in the low temperature region, is not only complicated, but also contains several ice phases. Most boundaries between the ice phases, and particularly those in the liquid phase, are parallel to the temperature axis, reflecting density-driven phase changes. There are also entropy-driven transitions, with phase boundaries parallel to the pressure axis. Marc Henry’s essay on the properties of supercooled water offers an intriguing top-level argument about one of the most fascinating behaviors of H2O.

"Despite being essential for daily life, water remains mysterious, exhibiting almost 40 anomalous properties. A partial list of its unexpected behaviors includes a high boiling point and surface tension; a high enthalpy of fusion—almost 41 kJ/mol, compared to 19 kJ/mol for H2S—which significantly lowers the cryoscopic constant; a maximum density at 3.98°C; a high melting point due to its low entropy in the liquid state; a lower melting point as pressure increases, and hence a negative value in the slope of the ∂P/∂T curve in the phase diagram, until about –22°C at 210 MPa; 9% volume contraction during melting, similar to other tetrahedral solids such as Si or SiO2; high viscosity and Arrhenius activation energy of the viscous flow; anomalous changes in its viscosity upon cooling, in high temperatures, and at high pressure; a low value of isothermal compressibility, and of isobaric expansion, high isobaric heat capacity in the liquid state, which drops 50% in the solid and vapor states; more neighbors in the liquid state with increasing temperature; a minimum in the solubility of gases and of scarcely soluble materials as temperature increases; and a large dielectric constant.

"Some of these anomalies are responsible for remarkable natural phenomena: icebergs float, energy from the sun is redistributed across the oceans and between the oceans and the atmosphere, capillary forces allow trees to lift enormous amounts of water to their leaves, climates in humid areas remain moderate, and natural convection occurs in water basins.

***

"More than 400 years later, a topic in this debate—the structure of liquid water—is still vigorously discussed. Investigations into short- versus long-range water structure have spawned a multitude of published studies. The existence of high-density versus low-density water has been invoked. Hydrogen-bond clusters in expanded or collapsed states seem to quickly change from one state to the other. The changes appear to depend on temperature, pressure, and the presence of solutes, proteins, and polysaccharides.5 If this is true, several anomalous features of water would be explained.

"Two other phenomena are challenging current scientific certainties in relation to water, and other liquids too: Hofmeister effects and dissolved gases.

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"Around 1888, Franz Hofmeister and his collaborators in Prague performed a simple experiment precipitating egg-white albumin in the presence of different salts, at the same concentration. They observed that solutions of some salts precipitated albumin more effectively than others. A year later in Saint Petersburg, Ivan Mikhaylovich Sechenov realized that scarcely soluble compounds such as gases possess different solubilities in salt solutions, depending on the nature of the electrolyte.

***

"The structure of water is elusive. The array and strength of interactions that keep water molecules together with such high cohesive energy determines their anomalous properties and, in particular, their interactions with solutes, whether neutral or ionic.

"It is not only life that relies on water. In the natural inorganic world, the most abundant minerals are silicates, carbonates, sulfates, aluminum, magnesium, calcium, sodium, and potassium. In the Earth’s mantle, the most abundant elements are magnesium 23%, silicon 22%, iron 5.8%, calcium 2.3%, aluminum 2.2%, sodium 0.3%, and potassium 0.3%. These ions are all strong or mild kosmotropes with important hydration layers. In contrast, the poorly hydrated chaotropes are not common in the natural inorganic world or in living systems. The large quantities of water found on earth and the origins of life may depend on these features.

Comment: Water is weird. Why do two gasses become a complex liquid? Nitrogen and oxygen, two gases make a gaseous product. My guess is God purposely created water with its strange and probably unknown properties first as as preparation for the subsequent creation of life. As we study natural products in great depth, what God has done makes lots more sense and removes questions we might have.