[NewCandle] crystallization weight change transients

[Nick Reiter]

Hello all,

Today, despite burning out my hotplate and having to
jerry rig another, I got a couple of runs done - one
very precisely - using the high purity aluminum
sulphate.  Very nice stuff - the supersaturated
solution is a little toffeenosed, but it's a modest
crystallizer speed wise (about like hypophosphite or
oxalic acid) AND it is nearly neutral in it's heat of
crystallization.  Full flask crystallizing in about 10
minutes, with only about a degree C of temp rise.

Results?  Negligible weight change - submilligram at
best.  Damn.

SO...ok, well I suspect it suggests a couple of
possibilities:

1.  The effect overall is a thermal artifact and there
is no anomalous weight change.
2.  Only those rapid crystallizing compounds that
evolve a lot of heat also show an anomalous weight
transient, placing the burden of de-coupling the
effects on the experimenter.

Of course number 2 can't be ruled out without due
process, although fuzzy Occam would say #1 is more
likely the case.  Still, I'm willing to stay on it for
a while yet, and try to get as good an effect with the
hyposulphite as I can with a fully matching thermal
dry run profile - degree for degree.

Now, Keith wrote:

> Good find Nick, that site's nice. But I just can't
> resist doubling up on it,
> I'm just that kind of an a-hole (grin).

*********As well it should be!  I'll see your a-holery
and raise you 100 grams of Woods Metal...

> So here's the idea. Melt some woods metal, you know
> the stuff,
> it's quite common for modeling purposes. Put it on
> the scale,
> and let it cool. Should be quite revealing. 

*************I have about a half kilo of Woods metal. 
I'll have to ponder the thermal logistics, but a
thermos bottle might be the ticket.  An excellent
idea, and I will try it out.  Muchas Gracias!

NR

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