Wrecking Bereserker
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Growing Lead iodide crystals help!
I reacted lead nitrate with postassium iodide to form lead iodide then i heated the solution to dissolve the lead iodide in water but the water just
boils and spurts PbI2 all over!what should i do?
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Ubya
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lead iodide has a solubility of 0.41g/100ml of water at 100 °C. you need more water and to cover you vessel so you don't get lead splashes...
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Boffis
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You are simply boiling it too vigorously. Lead iodide dissolves quickly up to saturation but even in boiling water its solubility is only about 4g per
litre. How much are you trying to dissolve? Did you measure the amounts of reactant you used? Did you mix them them in the correct Molar ratio? You
will need to gives us a bit more information before we can help.
By the way excess lead nitrate depresses the solubility of lead iodide while excess potassium iodide increases it until finally no lead iodide will
form at all on cooling only creamy yellow needles of a potassium lead iodide double salt.
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Sulaiman
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@ Wrecking Bereserker
just in case ... lead iodide is a cumulative poison,
(by mechanisms unknown to me) the iodine helps the lead enter your body, even through your skin.
Poisoning is (I've read) similar to lead poisoning.
Sorry if this is old news, just thought it best to mention it.
CAUTION : Hobby Chemist, not Professional or even Amateur
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beeludwig
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I've done this and have gotten the "golden rain" effect, I haven't tried making a larger crystal out of it although I'd like to. Wikipedia suggested
making the crystals by reacting the chemicals through a permeable barrier. I tried this and it just made a mess. I haven't really tried anything
else yet. Mostly because there's a limit to how much lead waste I want to make without a good way of remediating it.
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woelen
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If you boil the liquid with PbI2, cover the beaker or test tube loosely with a paper tissue. Any vapor/gases easily pass through, but small droplets
get stuck in the paper tissue. In this way you avoid exposure to lead salts.
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diddi
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i do not boil it. as soon as the PbI2 begins to disappear, it is hot enough.
[Edited on 14-5-2019 by diddi]
Beginning construction of periodic table display
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woelen
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But this only happens when you have a very small amount of PbI2 in the liquid. Otherwise you certainly will keep on heating, until the liquid boils.
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