exchemist

Forgive the question, but why do you want to do it this way rather than using a pH meter?

I was referring to MENSA. That's a club you choose to join, based on taking an IQ test. But I'm not interested in getting an IQ score either, actually. What would be the use of it? Everyone nowadays knows that IQ scores are a fairly poor predictor of people's capacity, in most spheres of activity. I've done OK in life - got to a good university and enjoyed my degree subject, had a reasonably fulfilling career, am able to understand and enjoy a lot of intellectual things. Nobody who knows me thinks I'm thick. That'll do for me.

Nah, I don't have enough of an inferiority complex.😄

Any marketplace involves competition and self-interest. The buyer's self interest is served by looking for the best quality or the lowest price and the sellers compete to offer that. That process is at best morally neutral. I see the free market, whether capitalist or not, as like nuclear fission: a great potential benefit but needing careful containment and control to prevent undesirable effects. That's what we have in practice. All the practical political arguments boil down to how much and what sort of controls. Some of these controls can provide incentives towards moral ends if well designed - e.g many of the current climate change interventions by governments.

OK, pKa of acetic acid is lower, so acetate will not tend to abstract H+ from HCO3-. Ah, so what you mean is that acetic acid would protonate HCO3-, leading to formation of carbonic acid, which then decomposes to CO2 and water. Yes, indeed. But what he have here is acetate not acetic acid. So I'm still not quite following you.

Not sure I follow this. Do you mean that because acetic acid is a weak acid, an aqueous solution of any acetate will be mostly in the form of undissociated acetic acid, thus making acetate salts net absorbers of H+ ions - and therefore basic?

You don't seem to be taking in the content of previous replies on this matter. 1) CaCO3 is largely insoluble. So a solution of ions containing Ca²⁺ and CO3²⁻ will precipitate out CaCO3. So that's why that one happens. As I explained before, if all the combinations of salts are soluble, all you get is a mixture of dissolved ions, as there is nothing to cause one compound to separate from the mixture. 2) Ca(HCO3)₂ does not exist in the solid state, as I pointed out on one of your previous threads. https://en.wikipedia.org/wiki/Calcium_bicarbonate If you want to know why it does not exist, that's a more complicated question, though we could discuss the reasons. My guess is it will be due to the difficulty in accommodating 2 large monovalent anions in a crystal structure with one smallish divalent cation. In other words the lattice energy is expected to be low, making formation of this compound in the solid phase energetically unattractive, relative to other options.

I realised you were being sarky, but thought it was a rather profound point nonetheless. When I lived for a couple of years in Houston TX, it took me a while to find out why I felt I didn't fit in and what I thought was lacking. In the Netherlands, by contrast, I felt at home in about a month. It really all boiled down to history, or relative lack thereof. New World countries, like the Americas and Australasia have an admirable energy and sense of the possible that we in the Old World have long since given up on. But we do have all the riches of history instead, which give us a certain groundedness. The backlash against globalisation is creating a new and ugly nationalist politics on both sides of the Atlantic. But recent polls show the British are now realising Brexit, at least in the absurdly extreme, ideological form in which it has been enacted, was a mistake. I think we are past the high water mark of naïve nationalism. I'm not too worried by private firms in the NHS, really. GPs have always been private, and the continental healthcare model, which often involves profit-making hospitals being block-contracted to the national health system, does not fill me with terror. My analysis of the US Healthcare system, on the other hand, is it is a broken market because there are two parties on the buying side of the equation, one with no market power and the other with no incentive to drive a hard bargain. The insurers have little incentive to query the bills for drugs and treatment and shop around - they just pass the costs through to employers' healthcare plans. And employees have no choice but to pay the premiums. A national healthcare system that buys care centrally from providers, on the other hand, has huge purchasing power and can really drive a bargain (as drug companies know to their cost, when selling to the British NHS.)

History does bog us down, certainly. But it is also enriching. I think it’s a good trade-off, but then I was born in Britain - in Scotland, actually.

And, believe me, it would be England. The Scots and Welsh would never accept such a thing!

Why not say that, then, instead of writing nonsense?

Basically, no.

Just re-read those last three sentences of yours. Slowly. And then confirm, just so we all know, whether you intended them seriously, or facetiously.

Consequently? We may understand how volcanic eruptions occur but we cannot manipulate them. Nor can we prevent the uncontrolled cell division that causes cancer, even though we understand the biochemistry. There's no "consequently" about it.

Exactly my thoughts on that, hence the question I raised initially. Though I take @swansont‘s point about different regions of the IR spectrum.

Well if it's just a few eggshells you won't have much material, so you could in principle dissolve any NaHCO3. The solubility seems to be 8.7g/100ml at room temperature. If you want to know what the precipitate is, you could try to wash it with a big excess of water and try a flame test. Ca will give you a brick red colour whereas Na will give a bright yellow. But any Na contamination can dominate because the Sodium D line(s) is(are) so strong, hence the need for washing.

And at the moment a lot of the advances seem to be occurring in the life sciences.

Yes, since bicarbonate and carbonate are essentially the same system, the only reaction you might get would be a displacement of ions if a new compound could form that was less soluble the they are and would preferentially precipitate out. But calcium carbonate is much less soluble than sodium bicarbonate, so you won't get many carbonate ions. Sodium carbonate is more soluble than either, and calcium bicarbonate does not form in the solid state at all.

Yes the solvent would have to be water, but in principle you could separate them this way. Though I agree the solubility of sodium bicarbonate is a bit limited so it would take a lot of water and a lot of evaporation. Context is almost always very helpful. Without context you may get responses that are not what you are looking for.

Yes, that can often work. Why not look up the solubility in water for both compounds, then, to see if it might do the job in this case?

No, I mean let's hear what your ideas are for how to separate the two, before we give you the answer. You see, you are asking a lot of very simple questions on this forum, which makes me wonder if you are a student trying to get help with homework. Can you suggest one possible technique for separating a mixture of two solids?

Rather than just offer an answer, let me ask you what ideas do you have about this, first of all?

Added to what?

This is all good stuff. The only unresolved issue now is the bit I read somewhere about absorption of IR by sulphate. I'll have to find that again and re-read.

Plausible. Do you know this is is why sulphate is considered a net anti-greenhouse emission, or is this just reasonable speculation? That sounds like it could be it. So we have three potential mechanisms: - selective IR absorption to block short IR from reaching the ground - efficient reflection/scattering by sulphate - nucleation for formation of high altitude clouds I'll have to try to read something on these to see what I can find.