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Rochelle Salt problem???


YT2095

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following the instructions here: http://seawhy.com/xlroch.html

with the only difference that I started with sodium carbonate and didn`t have to make it.

 

I seem to hit upon a problem, the Soln is like a syrup and is Not crystalising at all?

 

has anyone here tried this before, and is what`s happening Normal?

 

nowhere on the net that I can see does it even mention that the soln is Syrupy, the PH tests just fine also, I`m wondering if it`s in a metastable state?

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Solutions of Rochell's salt are syrupy so you probably have the right stuff. Because these solutions are viscous the process of crystalisation can be rather slow (the molecules have to move through the solution to get to the right places to crystalise).

I'd try putting the stuff in the fridge overnight then, when it's cold, taking it and stirring vigorously (classically with a glass rod if you have one).

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Thanks for the confirmation of that, I had all sorts of things going through my head thinking Starches added etc...

 

I took a small amount and heated to dry and then added that as a source for nucleation, now the whole flask is "going off" and quite hot too, it`s similar to Sodium Acetate, it would seem that my soln was in a metastable state.

 

the idea was to grow a nice Large Single Crystal, instead this is more like white Ice to look at. I have plenty of glass rods and the likes also, so I may just reheat it add a little extra water and try what you suggested.

 

I`m pleased that it`s behaving Normally though :)

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well the whole thing has solidified into a mass now, resembling frozen snow slush.

it`s all quite solid and not at all damp but I have taken it Out of the conical flask before it got Too solid and was impossible.

 

at least now I have a good place to work from :)

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Absurd as this sounds I think you need to add more water. Just enough to dissolve most of the solid at room temp. Then warm it up slightly to get the remaining solid into solution. Cool and add the seed crystal (that I forgot to mention earlier)- any speck of the solid. That should give you some crystals. If you let the stuff evaporate slowly you should net nice big crystals.

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done, and they`re growing Perfectly, not at all like snow, but Crystal clear (no pun intended). they`re Perfect and still growing.

it looks like I may get some perfectly workable crystals from this.

although the seed I used was a tiny spec of this "snow" like material, it seems to have given several nucleation sites, so I may redo this again using a better seed.

 

Thanks John :)

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I have no such ambitions, I just want to grow reasonable specimens that will demonstrate the Piezo electric effect as transducers.

 

and I`de like to see what happens when you pump a few 10s of KV through one too :)

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