Water; has unusual exotic features (Introduction)

by David Turell , Tuesday, April 14, 2020, 22:20 (1683 days ago) @ David Turell

Another review:

https://www.chemistryworld.com/features/the-weirdness-of-water/4011260.article?utm_sour...

"Water, the most commonplace of liquids, is also the strangest. It has at least 66 properties that differ from most liquids – high surface tension, high heat capacity, high melting and boiling points and low compressibility. One school of thought is that water is not a complicated liquid but ‘two simple liquids with a complicated relationship’. For some, this statement contradicts the basic principles of physical chemistry; for others it explains just why water behaves in such an anomalous way.

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"As you cool a liquid, its density increases, and its heat capacity and compressibility decrease. ‘Almost all liquids on the planet behave like that. Except for water.’ This strangeness comes into focus as water is cooled to 4°C, where its density reaches a maximum, below which it starts to decrease again.

"The explanation chemists are taught is that while most liquids are disordered, with their molecules constantly rearranging, water differs due to its network of hydrogen bonds. Hydrogen bonds have a strength in between stronger covalent bonds and weaker dipole-induced interactions. Unlike the latter, they are directional, with each hydrogen atom pointing towards an electron pair on an oxygen atom.

‘'It’s a lot of hydrogen bonding for such a small molecule,’ says Martin Chaplin,

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"There is still no consensus among physical chemists as to how water behaves. This may seem a purely esoteric debate, but water’s unusual properties, particularly at very low temperatures, do have implications for other areas of sciences. ‘It affects climate models [at] high pressure, [and] extra-terrestrial water [that] we might find on other planets, or [water in] nano-confinement,’ says Russo. For example, a recent study showed that water at the surface of droplets was much more ordered than bulk water and in a comparable state to supercooled water with strong hydrogen bonding, even at room temp erature.

"Whether a mixture of two liquids or just one, water’s properties are also fundamental to biology. ‘Water is the thing that gives [nucleic acids] their interesting structure and properties, and it’s the same with proteins,’ says Chaplin. Life itself has flourished because ice is less dense than water, allowing organisms to survive underneath floating ice layers. ‘What is interesting is we are peering into the region where life exists when [water’s anomalous behaviour] pops up,’ says Nilsson. According to his two-state model, it is only at temperatures below 50°C that water becomes a mixture of low- and high-density liquid and this is also the temperature region at which life exists. ‘Is this a coincidence, or is there something significant about that?’ asks Nilsson. ‘We don’t [yet] know.'’

Comment: Water is just like quantum mechanics, vital to reality and just as weird. God works in very mysterious ways to create this reality.