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exchemist

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Everything posted by exchemist

  1. And at the moment a lot of the advances seem to be occurring in the life sciences.
  2. 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.
  3. 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.
  4. 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?
  5. 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?
  6. Rather than just offer an answer, let me ask you what ideas do you have about this, first of all?
  7. 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.
  8. 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.
  9. I can't see how that can explain it because, as far as IR is concerned, CO2 and water would "shade" in the same way. The point about the greenhouse effect, as I understand it, is that incoming radiation of all wavelengths is converted to IR by the Earth's surface, re-radiated from it as IR - and is then absorbed and scattered by CO2 and water, ricocheting around the atmosphere instead of being emitted into space, and thus heating up the atmosphere. Shade as a mechanism can work if fine particles (whether sulphate or other) reflect radiation of all wavelengths (my previous comment about albedo - but in that case why would sulphate be specially effective?) or, I suppose, if they reflect just IR, but if they absorb IR they will heat up the atmosphere, won't they?
  10. Interestingly, a lot of articles on the effects of eruptions on climate mention sulphate aerosols in the stratosphere exerting a cooling effect. One or two tantalisingly refer to IR absorption by these particles. But I have trouble understanding this, as absorption of IR by CO2 (and water) is exactly what gives rise to the greenhouse effect. So how can what seems to be the same thing cause cooling? If it were a process of reflection, i.e. increasing the albedo of the upper atmosphere to reduce the sunlight incident on the surface of the Earth, that would be something I could understand. But in that case, why would sulphate aerosols be particularly effective? Surely any old dust grains might do the job? Does anyone know?
  11. You're a bit of a one trick pony, aren't you?
  12. Sorry, I really can't be bothered to wade through all this, er, stuff. Format it properly or I'm out.
  13. Yes, well, kinetic energy has to be specified with respect to a frame of reference, because velocity is relative. Why can't you post in normal length lines? This style is very exhausting to read. It makes one question whether it is worth the trouble.
  14. Do you know what specific heat capacity is? https://chempedia.info/info/calcium_carbonate_specific_heat/
  15. Nowhere. They could have said “underwent oxidation readily”, which in my view would have been better English. It’s just a qualitative statement about what they observed.
  16. But you asked about calcium carbonate. And neither has anything to do with hurting humans.
  17. My audiologist is called Pebbles - rather oddly for such a striking, statuesque black girl. While I'm sure it seemed like a good idea when she was a baby, I feel it hardly does her justice now. She could row at 6 in an VIII. But I am digressing.........😃
  18. What if the sky was made of concrete? Forget it. We can't hope to control volcanic eruptions.
  19. Definitely a case of “Don’t try this at home”. Nickel carbonyl is appallingly dangerous to health and carbon monoxide, which you would need, is also pretty lethal.
  20. Show us how you are going about this, first.
  21. What are you talking about?
  22. Per mole of what? If you mean per mole of water, taking water to be the principal component of the human body, then 4.2J raises the temperature of 1g by 1C deg. The MW of water is 18g, so 4.2 x 18 =75.6J raises the temperature of a mole of water by 1C deg. So 63.6kJ would be enough to raise its temperature by 63.6x 10³/75.6 = 841C, if there were no change of phase. I'll leave the rest to you.

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