I was planning this for about 1 year. I arranged everything to today.
I prepared this apparatus: 25 ml test tube filled with 3g of trichloroisocyanuric acid (I broke swimming pool tablet to pieces), to the tube was
attached a drying tube filled with granulated anhydrous CaCl2 and from the drying tube there was a narrow outlet tube. I filled 50 ml glass cylinder
with liquid N2 and put into it a glass tube which one end was already sealed. To the cooled tube I inserted the outlet tube from the Cl2 gas
generator. I added diluted HCl (35% HCl / H2O in ratio 1/1 so the HCl does not liberate HCl gas). The HCl was added in portions of approx 2 ml and
totally 10 ml added, it required to disassemble the ground glass joint between the test tube and the drying tube, quickly inject 2 ml of HCl using a
syringe and closing the joint. At the end I heated the test tube with small alcohol burner. When there was enough Cl2 collected (well, at that moment
I thought it was enough). I removed the outlet tube from the receiving tube and sealed the open end of the receiving tube using a flame burner. During
this operation I realized my burner was not too much powerful but at the end I managed to seal the open end. During sealing the chlorine was
solidified using liquid N2 so it did not evaporate while sealing the open end (blowing gas would prevent sealing). The receiving tube has 10 mm outer
diameter and 7 mm inner diameter so the wall thickness 1,5 mm.
After sealing some of the liquid Cl2 evaporated and filled the tube with Cl2 gas so the amount of liquid Cl2 decreased, but luckily there was still
some liquid. Well I expected to have at least 1/4 of the tube filled with liquid, but I have only approx 5%... anyway better than nothing.
I will very likely to repeat it again to fill more liquid Cl2 into such tube in the future as I have ideas what to improve the next time. I will
certainly thermally insulate the glass cylinder so the liquid N2 won't evaporate so quickly, I will also generate more Cl2 and fill the tube more than
I did today.
the apparatus, testing tube filled with TCCA, drying tube with CaCl2
the liquid Cl2 and above Cl2 gas under few atm pressure, the sealed tube almost empty, but luckily at least some liquid Cl2 present
[Edited on 11-12-2020 by Fery]
[edit by mod]
Title changed from "liquefaction" to "liquefication"
Apologies: the typo was seriously bugging me.
J.
[Edited on 12-12-2020 by j_sum1]Pumukli - 11-12-2020 at 13:32
Wonderful!
Chloros means yellow in greek but I always had the impression that this particular yellow is on the greenish-yellow side.
Well, I stand corrected, thanks!
Are you sure the melt end is safely closed? If you had trouble with the power of the torch it might just not be straightforward to achieve a good
bond. woelen - 11-12-2020 at 13:37
Very good result. This makes a beautiful element collection item, especially if you can get the tube filled a little more. I would go for 25% or so,
that leaves also plenty of space to see the color of the gas from different angles and through different thicknesses.Bedlasky - 11-12-2020 at 14:18
Nice result, Fery . Yellow colour of liquid chlorine is really wonderful.Fery - 11-12-2020 at 22:07
Interesting that not only the liquid, but also the color of the gas phase under few atmosphere pressure (so few times denser than at atmospheric
pressure) is also very well visible although the inner diameter of the tube is only small.
Pumukli - yes it is sealed well, it just took me few minutes to seal it (thickness of the wall 1,5 mm and even more at the sealed end and I had to
repeatedly interrupt the heating process and insert the other end into liquid N2, the next time I would like to seal it while inserted in liquid N2),
my 2 L flask with propan-butane contained already only little of the gas, that was the reason why the flame was smaller (I think the expanded gas
cools down the flask content faster which slows down the gas evolution). No leak visible yet - the content of the sealed tube is the same after half a
day. I will observe it further.
Woelen - very likely I will repeat the experiment again, I would like to fill such a tube more, having a tube with at least 1/4 of its volume
containing liquid Cl2 would be nicer.
Bedlasky - the next tube, if I manage to do it successfully, will be a gift for you. I expect to do it sometimes like in spring/summer, certainly not
earlier.DraconicAcid - 11-12-2020 at 22:16
Nice! I remember asking a science teacher about the possibility of doing that in the lab many, many years ago, but he absolutely refused to allow a
junior high school student to think about working with chlorine.Fery - 11-12-2020 at 23:31
DraconicAcid - well I inhaled a little of the nasty Cl2 and the bad feeling in nose/throat disappeared after more than 3 hours (I was still feeling it
while writing the first post). Now I have a little bit more of skill, I would use different apparatus without necessity to open the joint to inject
HCl and also start the generator when the outlet tube already inserted in receiving tube. I did it for the first time in my life and probably caught
all points of weakness / what to improve the next time. This was just my initial pioneering experiment in this part of chemistry and I have a lot of
things to improve.j_sum1 - 11-12-2020 at 23:31
This is on my to do list for my element collection. It has been for some time. But I figure the more experience I get before I do it myself, the
better. Beautiful result. Congratulations.Fery - 12-12-2020 at 00:13
j_sum - I understand. I was postponing it for 1 year. Definitely worth of trying it. Maybe more times, for the first time you will find some ideas
what to improve and on repeating experiment it will get better and better. Yes try sealing empty tubes, so finally you seal filled tube as fast as
possible. Also solid CO2 could be used. During the sealing process it is necessary for the Cl2 not to evaporate / escape the tube otherwise the
sealing process maybe impossible - I had Cl2 in solid state thanks to liquid N2, but perhaps also liquid Cl2 (when using solid CO2) could be fine,
just in that case seal the tube faster than me or maybe not so thick glass wall necessary (perhaps 1 mm enough?) so sealing faster.AJKOER - 13-12-2020 at 05:46
I once prepared solid needle crystals of chlorine hydrate (the very cold outside weather was accommodating to its formation around the freezing point
of water).
I noticed on warming a reversion back to Cl2 and H2O.
However, related to this thread, what would happen if one sealed a filled tube with the chlorine hydrate and let it warm? Colored chlorine water or
more clear solution of HCl+HOCl or something more interesting?
If the sealed HOCl composition is subject to UV light exposure (from, say, sunlight reflected off of snow which is UV richer):
2 HOCl -> 2 HCl + O2
what state is the oxygen in?
Or, does this experiment just create HClO3 or an energetic chlorine oxide?
In the latter case, anyone performing this experiment should wear appropriate protection working on a small scale.
[Edited on 13-12-2020 by AJKOER]Tsjerk - 13-12-2020 at 08:42
However, related to this thread, what would happen if one sealed a filled tube with the chlorine hydrate and let it warm? Colored chlorine water or
more clear solution of HCl+HOCl or something more interesting?
Nothing but chlorine and water. The equilibruim forming HOCl and HCL is only pulled by bases, which are not present.
What does look interesting is a V-shaped glass tube filled with chlorine and water. Playing with different temperatures on both sides off the V would
form different hydrate compositions, which would also be reversible,
