exchemist

There is no difference, fundamentally, so you are right not to see it, I think. Schrödinger had some funny ideas in later life, as quite often happens to famous scientists. Many processes in nature involve decreases in local entropy, that is, in part of the thermodynamic system. But they are always accompanied by a greater increase in entropy in some other part of the system. For example, when water freezes, the entropy of the ice crystals is lower than liquid water, but Latent Heat is exported to the environment, increasing its entropy. Similarly, the metabolic processes of life generate waste heat. So entropy increases all the time a living organism grows. There is nothing special going on, thermodynamically speaking.

No, the opposite of random is something like "ordered" or "predictable", for example the motion of the planets. As for entropy, I think what you mean is what the Second Law of Thermodynamics predicts, which is that entropy (a measure of randomness at the atomic scale) always increases in spontaneous processes. That is just as true of life as it is of inanimate matter. If you need an explanation of how that happens, we can easily provide it.

Nobody has ever argued that the complexity of life is due to randomness alone. That's a particularly silly - and annoying -creationist representation of evolution (tornado in a junkyard etc). The complexity of life is due to natural selection operating on variations in a population. There's nothing random about selection. So we can dismiss the monkey argument as far as life is concerned. When it comes to non-living "complexity", it is unclear to me what you mean. The anthropic principle is not about complexity, so I don't really follow where your hypothetical monkeys come into it.

Like all these things it gets more complex when you delve into it. Electron affinity is the energy released by an electronegative atom when it gains an extra electron and becomes an anion. For example, all the halogens release energy on gaining an electron, meaning the anion has lower energy than the neutral atom. The same is true for oxygen when it gains one electron. However when it gains a second, that is energetically unfavourable, due to the repulsion from the net -ve charge of the anion towards a second electron. (I had forgotten this, and only remembered after looking it up.) However electron affinity is only a measure of the energy change when a free atom or ion gains an extra electron. In the case of metal oxides, the oxygen atom is not free. It is sitting in a crystal lattice, in the present case (CaO) surrounded by 6 nearest neighbour Ca2+ ions. That makes its environment much more energetically attractive for oxygen to pick up a second electron and form O2-. Hence it is common to find metal oxides with O2- anions even though, if the oxygen atom were free, you would have to "force" it to accept a second electron. (It's significant that if you put these oxides in contact with water you never get hydrated O2- ions. When they come out of the crystal lattice they pinch an H+ ion from water to make OH- (hydroxide) - plus another OH- from what is left of the water molecule: O2- +H2O -> 2OH- . As for the question about close proximity lowering potential, that's just replaying what you said, in effect, about magnets. You bring opposite magnetic poles together, or opposite electric changes together, and you lower the magnetic or electrostatic potential energy. That is reflected in the fact that you have to do work to pull them apart again. And, as they come together, magnets can gain kinetic energy, just as you said, at the expense of the magnetic potential energy. Similarly, ions with opposite charges approaching one another gain kinetic energy at the expense of electrostatic potential energy - which, in the context of molecular scale processes, means the heat energy given off in an exothermic reaction. The alkaline earth (Group II) metal oxides react with CO2 in the air, yes. I'm less sure about the alkali (Group I) metals. The carbonate anion has a charge of 2- and this means it needs 2 M+ atoms to go with it, so I'm not sure how the kinetics and thermodynamics of that work out.

There is no real distinction, though I suppose someone might - rather loosely - speak of a "vapour" until the critical point is reached, i.e. the point at which the gas/vapour can't be liquefied by application of pressure. But whether you call it vapour or gas, it is the same state of matter.

Er, I'm not asking for better example of anything. I'd like to know how the argument goes that WW1 could have been avoided if Germany had had a bigger navy. It seems to me that, seeing as France and Russia had a mutual defence pact, the war did not hinge on the UK's participation.

Yes you are right, the answer I gave before was a simplistic one, for ionic compounds generally. The case of these oxides is a bit more involved, since in fact the second electron affinity of oxygen is +ve, endothermic. The stability of compounds like CaO relies on a high lattice energy, i.e. the reduction in electrostatic potential that comes from close approach of a large number of oppositely charged ions, in a crystal lattice. In the case of CaO, the O2- anion and the Ca2+ cation are of very similar size, allowing a very efficient packing arrangement which minimises inter-ionic distances, releasing more energy, which compensates for the energy required to get a second extra electron onto the O atom. So my first answer was a bit misleading. Sorry about that.

How does that work? I would have thought the Franco-Russian Alliance would have ensured the war took place, regardless of the UK's desire to take part.

No. The reason is to do with oxidations states. Ca2+ cations are already "oxidised", in that they have a +2 oxidation state, which is the highest possible for them in normal chemistry. (Ca metal, in an oxidation state of 0, reacts vigorously with oxygen.) Another way to think of it is that CaO is comprised of Ca cations with a charge of 2+ and oxide anions with a charge of 2-. In the course of the reaction between a Ca metal atom and and an oxygen molecule, two electrons are transferred from Ca, which binds them weakly, to O which binds them strongly. This results in a net release of energy, leading to a compound has lower chemical energy than the starting materials - which is the direction all spontaneous chemical reactions take. Whereas if you try to react Ca2+ cations with oxygen, they have no more electrons to give up, so nothing happens.

Recital of this victory for England always reminds me of the curious fact that at school we learned about this battle, Crecy and Poitiers, but were never told that England lost the Hundred Years War, to France. It's one example of how history is often taught, or recollected, in a partial way, in order to bolster national myths. These national myths can have real consequences.

My son is, and I try to keep up, a bit. His main interest is the ancient world, but not exclusively so. I would certainly be interested in reading threads on that subject, anyway.

Any fool can ask questions. Providing answers that are valid is a little harder, considering that imagination does not help much with that.

In principle yes, the body's processes for regulating pH, e.g. the operation of the kidneys which transport substances against a concentration gradient, or breathing more rapidly to reduce the CO2 in the blood, can involve some energy expenditure. But only to a very minor degree and certainly not in the range it would need to be as a factor in dietary calorie control.

Then the reaction has not yet reached equilibrium. Equilibrium is when the forward and reverse reactions are in balance, i.e. the rates are the same.

I have no experience with this myself but my general understanding is that the adsorption capacity of activated carbon goes up with molecular weight of the substance to be adsorbed, and goes down with the degree of solubility of the substance in water. On this basis I would not expect it to be very effective at removing alkali metal cations or carbonate anions. But there may be someone else here who knows more about this in practice.

That's interesting. What's the evidence for these allegations?

Er, no it isn't, actually. But this is too bonkers for me. I'm out.

But that is not evidence that the experiment was biased. He may simply have hoped, or expected, that a fair experiment would make his point for him. Plenty of scientists carry out experiments in the hope or expectation that their hypothesis will be confirmed by it. It's one of the most normal motives for doing science. What, in your opinion, is the evidence that the experiment itself was biased?

What makes you think the diameter of the moon has any relation to the distance between Tierra del Fuego and the tip of Antarctica?

Hmm, well done...but this looks like an amateur site and possibly pirated. I wonder if the site owner has got copyright licence from CRC to do this.

Very interesting. In the case of Brazil, there should be access to gypsum, I'd have thought.

Where are the "locals", if I may ask? I have not read about many places with strongly alkaline soil. I suppose parts of the African Rift Valley would be one of them. But in most places where pH needs adjustment, it seems that the issue is the soil becoming too acid.

A further thought on this: H-bonds seem to need to be linear, i.e. Do-H............Ac, in a line. Also, they are directional, requiring the participation of a lone pair on the Ac atom. In o-nitrobenzoic acid, it seems to be geometrically impossible to get (CO)O-H........O(-ON-Ph) in a line, with one of the nitro group oxygen lone pairs lined up the right way. So I wonder if, in fact, there is any H-bond at all in this molecule!

There is breakdown here of CO2 emissions by economic sector:https://www.statista.com/statistics/276480/world-carbon-dioxide-emissions-by-sector/ And here is a split of powergen by type of generation: https://en.wikipedia.org/wiki/World_energy_consumption You could use this to see what the impact would be if most electricity generation were nuclear. You can see from these figures that power generation is a very large contributor to CO2, so it would make quite a large difference. But I'm not going to go through the number crunching on this: you can do that.😉

I have to say this whole exercise strikes me as pointless. A factor of 2 is not going to make a material difference to how an expression is seen, to anybody who is even remotely used to algebra. As you yourself say, 2π pops all over the place. So "2π" is read and recognised as a familiar symbol already, in its own right. Replacing it by τ won't reveal anything. It may in fact momentarily confuse people who are not used to seeing τ used in this way, as it has other meanings in physics.