[NewCandle] crystallization weight change transients

Sun Sep 24 13:38:20 EDT 2006

Hi Nick,

Nice work, as always!

Unfortunately, I don't have a scale that can do better than
100 mg or I'd try this experiment myself. If I did, I might
try the old chemistry prof. standard, sodium acetate, which
crystallizes very rapidly and is easy to work with.
Here's a link to illustrate.

http://www.csudh.edu/oliver/demos/supersat/supersat.htm

Of course, one would have to address the heating of the
flask, perhaps a null experiment with a heater would
give one a sense of how big a "lift" would be expected.

Given the results of your experiment, it sounds
like Berens and Singer were able to achieve a much
higher concentration of salt in solution, and thus
a much larger temp difference and resulting lift from
heating. It seems from the written report that they
tried to adjust for this, but as you say, one might
expect substantial lift from the large temperature
difference they achieved. Although it sure seems like
the two effects ( heat + weight loss ) go together,
it's probably a big mistake to assume that artifact is
all that is being measured. What's needed is a good
null experiment. Let me think on that a bit.

I think to address Colin's point, the more salt you
can get into the supersaturated solution, the faster
will be the phase change. Not sure that any catalysts
are needed, rather you would need to buckle down and
figure out the "secret" to make _really_ supersaturated
solutions. It sounded like Nick was having some heatburn
working the hypo solution; I'm looking around on the
web for advice on preparation but no luck, other than
the advice of very slow cooling. Maybe the "secret" is
just great patience... I did find this though, probably
of general interest seperate from the task at hand.

http://www.xray.ncsu.edu/GrowXtal.html

It also strikes me from watching salts dissolve at room
temp that you can usually get a great deal more salt to
dissolve over the course of say, a month, than you would
over the course of an hour. I'm sure the same is true at
elevated temperature. So my protocol might be,

1)Heat water to a given temp, in a refluxing flask.
2)Add _lots_ of the salt.
3)Keep at the target temp. for a period of about a week or so...as long as you can.
4)Then cool _slowly_ to room temp.

K.

-----Original Message-----
From: newcandle-bounces at ipdiscover.com
[mailto:newcandle-bounces at ipdiscover.com]On Behalf Of Nick Reiter
Sent: Saturday, September 23, 2006 5:10 PM
To: New energy for the new world.
Subject: [NewCandle] crystallization weight change transients

Hello, all,

The past two weeks have seen some rat-like scurrying
in the lab, and some experiments long overdue, coming
to the table!  The topic is claimed transient weight
changes accompanying crystallization out of saturated
solutions.

Back earlier in the summer, Colin Q. sent me an
excerpt from a 19th century text he had obtained that
concerned such anomalies:

"SOME UNRECOGNIZED LAWS OF NATURE"
"An Inquiry into the causes of physical phenomena with
special reference to gravitation"

 Ignatius Singer and Lewis H. Berens.

1897- London - pub: John Murray, Albemarle Street.
Oxford.
Horace Hart, Printer to the University.

In the excerpt, the authors of the old book claimed
they had observed transient weight changes in material
samples that had undergone excitation and phase
changes – much along the lines of Kozyrev, Brown, and
my own observations.  One particular experiment was
described in detail, and Colin felt it would be worth
my attention to try to replicate, given my access to
balances and chemicals.

That is what I have been playing with the past two
weeks.  Here is the excerpt I have been working off
of:

***********

Chapter V -- Gravity  (pages 373 to 394)

  QUOTES:
(p. 383.)
"{...} As already mentioned, a platinum crucible after
having been heated and just allowed to cool, so as to
be no longer sensibly warm to touch, still weighs
less, if immediately placed on the balance, than its
original weight ; and it will often take many minutes
until the balance will again assume it's normal
position. Our explanation of this is that, though cool
to the touch, the molecules are still in a state of
excitation, and hence their lesser weight..
           Still more definite are the results of the
following experiment. A supersaturated solution of
sodium hyposulphite was obtained by dissolving three
parts by weight of the salt in one part of hot water,
and allowing it to cool. The glass-stoppered flask was
then placed on the balance and weighed along with a
small crystal of the same salt. By now dropping the
crystal into the solution, crystallization set in ;
and although the weight of solution, flask, and all,
did not exceed 60 grammes, and the difference of
temperature before and after crystallization was not
more than 20 degrees C. (at the utmost), the
difference in weight amounted to 25 mgr. : whereas
with a brass weight of 100 grammes and a difference of
temperature of over 80 degrees C. the difference in
weight was only 10 mgr. Whether this difference in
weight be attributed to ascending air currents or to
expulsion of moisture from the pores of the glass (?),
these facts would remain unexplained. Moreover, in the
case of the heated brass weights equilibrium is
established in a comparatively short time, whereas in
the case of the hyposulphite it requires several
hours."

 (p. 386.)
 "2.     That in the case of bodies weighed during or
immediately after crystallization ( as with a cold
saturated  solution of sodium hyposulphite ) the loss
in weight is considerably greater than with, say,
metals heated to a much higher temperature.
           The heat evolved by crystallization is
sleight, the flask being just warm to the touch ; and,
for purposes of comparison, the metals may be enclosed
in similar flasks, with the same general results
stated above ; that is, the hyposulphite will sustain
a much greater temporary loss of weight than the
metals. Yet under such conditions, whether the lesser
weight be ascribed to air currents or to loss of
moisture, the metals (being about 60 degrees
Centigrade hotter than the solution ) ought to be the
lighter."

********

Week before last I had placed an order for what I
thought was the right chemical, but it turns out I
misread the excerpt, and I thought Berens and Singer
had used sodium hypophosphite.  Oops.  I promptly
ordered the right material, but in the meantime also
received the hypophosphite, which I felt would be
worth trying as well.  I thus ended up trying the
described experiment with sodium hypophosphite before
doing the actual verbatim replication using the
hyposulphite (which is now called sodium thiosulfate,
by the way.)

Short summary thus – with both the sodium
hypophosphite and sodium hyposulphite I saw a
reversible weight loss of a couple of milligrams, over
roughly the time of maximum crystal growth.  I did not
see the 25 milligram weight change claimed by Berens
and Singer.  I attempted the procedure with copper
chloride, nickel chloride, and oxalic acid.  The two
chlorides proved too problematic and touchy for
finding a supersaturated condition that wouldn’t
re-crystallize spontaneously before the seed crystal
was added.  The oxalic was a decent player, though I
saw maybe a milligram at best with that one.

>From my more formal report, which is in progress, here
is a detailed description of the sodium hypophosphite
run.  I have not yet written up my raw notes for the
hyposulphite run, which was only yesterday:

***

Experiment #1
Prep. 9-16-06
Performed 9-18-06  10:45EST

By trial and error, we obtained a stable
supersaturated solution of sodium hypophosphite
monohydrate (ACS grade, Alfa Aesar) in DI water.
Total end volume of the solution was slightly less
than 40ml; total amount of NaH2PO2 used was
approximately ~35 grams.  The solution was prepared at
about 60 C on a hotplate and allowed to cool to near
room temperature (~26C).   To prevent “skinning”
crystallization, individual drops of water were added
until the skin just disappeared.

The solution was decanted to a cleaned and baked 100
ml pyrex volumetric flask with a glass stopper.  The
flask and stopper were positioned on the balance pan
of our Stanton Unimatic milligram balance and were
found to show a weight of 122.069 grams.  A
thermocouple probe showed that the outside glass
temperature of the flask at just below the solution
line was 26C.  Room temperature appeared to be between
24 and 25 degrees C.

Four well formed crystals (about 1.5 to 2mm on a side)
of NaH2PO2 were selected and placed on the balance pan
beside the flask.  The weight of the flask, contents,
and seed crystals came to 122.090 grams.

We then removed the flask from the pan, removed the
stopper, inserted the four seed crystals, re-inserted
the stopper, and placed the flask back on the balance
pan.  The weight was still found to be 122.090 grams.

Within seconds of insertion, fine dendritic or
needle-like rapid crystallization began to spread out
from the seeds.

At about T+ 2 minutes, we noticed the start of a
weight change of the flask and contents.  At T+ 5
minutes the total weight had decreased one milligram
to 122.089 grams.  At around T+ 10 minutes, a maximum
weight deviation of slightly less than -2 mg was
observed.  Somewhere between 25 and 45 minutes, the
weight of the system began to return to its original
value which was reached at a little over T+60 minutes
from start.

At T+ 5 minutes, the temperature of the outer surface
of the flask was measured again, and was found to be
yet 26C.  A final measurement of the flask temperature
upon return to the original starting weight of 122.090
grams was made and found to be 25C.

It should also be noted that the growth of the
crystals appeared to reach its conclusion between
about T+ 5 to T+ 10 minutes – potentially
corresponding to the observed weight change maximum.

Weight change data:

Before seeding – 122.090 grams total weight.
Temp=26C

T+0 after seeding – 122.090 g

T+5 min. – 122.089 g       Temp=26C
T+10 min – 122.088+ g (slightly above last digit)
T+20 min – 122.088+ g
T+25 min – 122.088+ g
T+45 min – 122.089 g
T+65 min – 122.090 g       Temp=25C

***

As in most of my rounds with weight change transients,
the possible artifacts are insidious.  In this case
the main complication is heat of crystallization /
solution.  In the case of the hypo-S, this is
considerable, and the temperature of the flask under
test was raised a good 5 degrees C.  With the hypo-P,
the temperature rise was less than a degree C during
crystallizing
 thus making the hypo-P a more
convincing material to work with.

As of right now I believe there is enough potential to
keep working on it, and that technically I did get a
small positive replication of the Berens and Singer
experiment.  On the other hand, if they were seeing up
to a 20 degree C rise on the test flask, I could
easily see this would likely influence the balance
reading, despite their commentary to the contrary.

Heat of solution, heat of hydration, and lattice
energies would be useful values to include in the
evaluation of this type of experiment.  My old CRC
manual has some limited values listed, but not for the
compounds I have been trying to look at.  Anyone out
there have some good thermodynamic data tables?
On-line references anymore are all “pay-only” it
seems.

Insulating my test flask and calibration of the same
for “weight versus temperature” air current and
buoyancy effects are in order for the next round.

Special thanks are due to Colin for getting the ball
rolling and turning me on to this peculiar old
experiment!

NR

__________________________________________________
Do You Yahoo!?
Tired of spam?  Yahoo! Mail has the best spam protection around
http://mail.yahoo.com

_______________________________________________
NewCandle mailing list
NewCandle at ipdiscover.com
http://ipdiscover.com/mailman/listinfo/newcandle_ipdiscover.com