Earlier, I constructed a possible model of hydronium hydroxide, or H3O+.OH– One way of assessing the quality of the model is to calculate the free energy difference between it and two normal water molecules and compare the result to the measured difference. Here I apply a further test of the model using isotopes.
Posts Tagged ‘thermodynamics’
Deuteronium deuteroxide. The why of pD 7.435.
Friday, April 22nd, 2016Tags:dielectric, energy, free energy, Heat transfer, Heavy water, Kilocalorie per mole, model is to calculate the free energy difference, Properties of water, the free energy, thermodynamics, Tritiated water
Posted in Interesting chemistry | 4 Comments »
The Cyclol Hypothesis for protein structure: castles in the air.
Monday, April 4th, 2011Most scientific theories emerge slowly, over decades, but others emerge fully formed virtually overnight as it were (think Einstein in 1905). A third category is the supernova type, burning brightly for a short while, but then vanishing (almost) without trace shortly thereafter. The structure of DNA (of which I have blogged elsewhere) belongs to the second class, whilst one of the brightest (and now entirely forgotten) examples of the supernova type concerns the structure of proteins. In 1936, it must have seemed a sure bet that the first person to come up with a successful theory of the origins of the (non-random) relatively rigid structure of proteins would inevitably win a Nobel prize. Of course this did happen for that other biologically important system, DNA, some 17 years later. Compelling structures for larger molecules providing reliable atom-atom distances based on crystallography were still in the future in 1936, and so structural theories contained a fair element of speculation and hopefully inspired guesswork (much as cosmological theories appear to have nowadays!).
Tags:Cambridge, chair, Derek Barton, Dorothy Wrinch, energy, high energy species, Historical, mathematician, organic chemist, Patrick Coffey, relative free energy, thermodynamics, Tutorial material
Posted in Interesting chemistry | 2 Comments »