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  • now I've seen this reaction lots of times, but this is the first time I've seen it in high speed, where we pulled the solution in quite slowly, but then watch what happens.

  • But with reaction of copper with ammonia is quite a well known reaction on often.

  • Student schoolchildren come across it quite early on in their career.

  • Yeah, it's a reaction, which gives both a precipitate and then a color change.

  • It involves copper sulfate, which in solution is a fairly pale blue and you can imagine in the solution you have copper iron.

  • See you two plus, surrounded by six water molecules for the too close together, and to that, the rather further apart.

  • This does not absorb like very strongly, so the solution looks very pale when you add ammonia, which is alkaline in when it's dissolved in water, you precipitate a pale blue solid, which is a mixture of copper hydroxide and copper sulfate, so called basic salt, and then a duet Maur ammonia.

  • This re dissolves to give a very intense blue color.

  • The blue color is due to copper irons, the same cop Ryan's, but now, with four ammonia molecules interacting with it, in the Tetra, he'd roll shape.

  • This is a baby toy that I got in Italy.

  • It's quite fun.

  • So there aren't really Jules and cheese attached.

  • Oh, no, no, no.

  • This is just This pizza was well, that way.

  • Copper goes from this shape that is quite pale colored to this one that is Tetra hydro.

  • The color comes much more intense, and it is a very nice demonstration for people just beginning chemistry to see how copper conform so called coordination complexes, where stable molecule like ammonia can actually bind to the copper Ryan's on What I find quite surprising is if you watch carefully, it really goes blue, dark blue before you see the precipitate, whereas chemically it should be the other way around, you should see the precipitate and then the dark blue color.

  • And my only explanation, and this may well be wrong is that it takes time for the precipitate to form crystals that the big enough to see when Chris lights are very small.

  • Their size is shorter than the wavelength of light, so they appear invisible, though they can still absorb light.

  • And then as they grow bigger, you see physical clumps of thumb because they're much bigger than the wavelength of light on this growing of particles can be relatively slow compared to the initial precipitation which forms really tiny ones.

  • When you looked at the end, it looks rather beautiful.

  • It looks very like the planet Earth seen from space No.

now I've seen this reaction lots of times, but this is the first time I've seen it in high speed, where we pulled the solution in quite slowly, but then watch what happens.

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