Sciencemadness Discussion Board - What to do with chlorine gas ?

What to do with chlorine gas ?

Sulaiman - 11-5-2016 at 01:46

This weekend I hope to set up a generator of hot dry chlorine gas for my 'Dragon's Blood' synthesis (AuCl₄)
so I am wondering what other syntheses I may use chlorine gas for while I have the generator set up ... ideas/suggestions ?

If my titanium arrives in time I may try TiCl₄
but I can't think of any useful reagents to synthesize.

[Edited on 11-5-2016 by Sulaiman]

j_sum1 - 11-5-2016 at 02:12

There is always sulfur dichloride and sulfur monochloride -- https://www.youtube.com/watch?v=oYw89ieffa4 I understand it is quite a bit of fun.

Some AlCl3 springs to mind. FeCl3 is also a possibility.
And all else failing, you can attempt bromine production by displacement with Cl2.

Maybe have a shot at ampouling some. If you have access to dry ice or even better, liquid nitrogen you could set up a little production run. A couple of dozen of those sold on eBay should land a tidy profit.

As a side note, I had a thought on the AuCl3 synthesis. I have some gold leaf. I wondered about laying it on a piece of glass and putting it directly in a stream of dry chlorine gas. I don't know (and haven't looked up) whether gold will react directly with chlorine or whether it is necessary to go via chloroauric acid. But it seemed like a relatively simple set-up to attempt. One of the positive aspects if it works is that you should end up with an even dispersion of the crystals on a microscope slide ready for viewing.
Thoughts?

TinSandwich - 11-5-2016 at 03:49

What about making FeCl3? (https://www.youtube.com/watch?v=KRvqv5KQysg) It's like fireworks but toxic! Yay!

j_sum1 - 11-5-2016 at 04:06

Come to think of it, some anhydrous SnCl2 might be a useful thing to have on hand too.

RogueRose - 11-5-2016 at 05:02

S2Cl2?

Chem Rage - 11-5-2016 at 05:31

Chlorine has so many different chemical applications. For obvious reasons, avoiding breathing it in and ensure very good ventilation. Whenever I carry out reactions with Cl2, I do so on a very small scale using my smallest spec glassware. I also bubble unreacted Cl2 "exhaust" gas into a chemical scrubber consisting of a concentrated solution of sodium thiosulphate, which reduces the Cl2 to harmless chloride.

Cl2 (dried) is useful for preparing anhydrous metal chlorides that are prone to undergoing hydrolysis if exposed to water or moisture. The oxidising properties of Cl2 can also be utilised in the preparation of other halogens, except for fluorine.

[Edited on 11-5-2016 by Chem Rage]

[Edited on 11-5-2016 by Chem Rage]

Daffodile - 11-5-2016 at 05:59

Putting hot aluminum in chlorine gas is a good demonstration. You could also chlorinate ethanol to acetaldehyde.

Eosin Y - 11-5-2016 at 06:59

What are you using as a chlorine generator? Trichloroisocyanuric acid-hydrochloric acid?

XeonTheMGPony - 11-5-2016 at 07:20

Quote: Originally posted by Eosin Y

What are you using as a chlorine generator? Trichloroisocyanuric acid-hydrochloric acid?

I prefer the electrochemical method, gives me precise control of volume.

aga - 11-5-2016 at 08:15

Quote: Originally posted by XeonTheMGPony

I prefer the electrochemical method, gives me precise control of volume.

Stoichimetry also works

I like a Balloon instead of an excess gas scrubber.

woelen - 11-5-2016 at 09:06

Do you have KI, NaI or KIO3 and one of NaOH or KOH? If so, then you could try to make the very interesting periodate salts:

http://woelen.homescience.net/science/chem/exps/KIO4_synth/i...
http://woelen.homescience.net/science/chem/exps/Na2H3IO6/ind...

mayko - 11-5-2016 at 09:43

Bubble it through water; toss in some calcium carbide; watch them spontaneously combust when the bubbles merge.

Many videos of this seem to be rather careless in regards to their handling of chlorine; maybe you can make a better one:
https://www.youtube.com/watch?v=1QDGxY_oQVg
https://www.youtube.com/watch?v=1Y5aCSOSQgU

myristicinaldehyde - 11-5-2016 at 11:50

Make silicon tetrachloride! Fun stuff.
It's used to make some more exotic, less eye-destroying silicon compounds, but it's cool in its own right.

Sulaiman - 11-5-2016 at 14:22

WOW !

I'm overwhelmed, lots of reading to do. thanks to all.

I intend to use 15% sodium hypochlorite solution dripped into 36% HCl to generate chlorine gas.

aga - 11-5-2016 at 14:34

Get DCCA or TCCA pool shock instead.

Much simpler.

Sulaiman - 11-5-2016 at 21:57

Maybe, but I have most of a litre of 15% sodium hypochlorite solution in a hdpe bottle that looks a little like a balloon when in hot weather,
so I may as well use some before summer.
If my initial attempts are successful then I may make a YouTube video, in which case I may use TCCA to allow easier replication.

aga - 12-5-2016 at 00:08

When i tried it with bleach the foaming agents/surfactants frothed up like crazy.

Sulaiman - 12-5-2016 at 04:40

aga
My 'bleach' was sold as sodium hypochlorite 14% - 15%,
I will test this evening to see if it foams.
I measured the pH at 12.3 so c1% w/w NaOH stabilizer.

I ordered some TCCA tablets last night since others may not have access to 15% non-foaming NaOCl, plus I've not tried TCCA yet.

mayko
The Cl₂ + C₂H₂ looks fun and i have calcium carbide so that one is on the list.
The safety in those videos was adequate, very low volume of escaped chlorine gas.

woelen
yes, I must have a go at periodates, thanks.
Can I just use KI instead of KIO₃ as on your website ?

plus, my titanium arrived yesterday so a little TiCl₄ too.
I may even try freeing a little bromine from KBr.
that should keep me busy this weekend

j_sum1 - 12-5-2016 at 04:47

Quote: Originally posted by Sulaiman

mayko
The Cl₂ + C₂H₂ looks fun and i have calcium carbide so that one is on the list.
The safety in those videos was adequate, very low volume of escaped chlorine gas.

I just posted a couple of books on chemical demonstrations: http://www.sciencemadness.org/talk/viewthread.php?tid=28848&...
The C2H2 / Chlorine reaction is in one of these books. (I think the second). Full procedure is given. It really is a lot of fun! But it is rather energetic as you would expect.

[edit]

You seem to have been rather busy with your chem recently Sulamain. Lots of interesting ideas percolating in that brain of yours and some nice experiments attempted. As always, I am looking forward to some more lab time. I hope you have a nicely chlorinated weekend.

[Edited on 12-5-2016 by j_sum1]

AJKOER - 12-5-2016 at 05:28

Try mixing dry Cl2 and H2 absence any oxygen (exactly how to remove small amounts of water vapor and O2 may require some thought and experimenting). The presence of oxygen apparently terminates the light induced H2/Cl2 chain reaction.

Also, no water vapor as this introduces unstable HOCl (from the action of Cl2 and water) which can decompose liberating some oxygen.

Use a uv light pointer to ignite the H2/Cl2 mix in a highly kinetic explosion (so small volumes only).

Videos available online. See https://www.google.com/search?sclient=tablet-gws&site=&a...

Safety precautions a must!

[Edited on 12-5-2016 by AJKOER]

Sulaiman - 12-5-2016 at 21:32

Although the H₂ + Cl₂ + light is a tempting experiment,
I am avoiding experiments with significant explosions as I don't want to worry my neighbours or get any hassle,
as a teenager I made MANY explosions, all the neighbours knew it was me but did not complain,
but society is not as tolerant of such things now,
and in the current environment, if I thought a muslim neighbour was making explosives I'd be concerned too, and I'm a muslim !
I try to avoid lots of smoke or smell for similar reasons, even though my neighbours know of my hobby.

AJKOER - 13-5-2016 at 05:25

Sulaiman:

I agree with your comments.

The last time I made a chemistry related comments to a stranger, they ask me if I made drugs! I think of this as a societal consequence of the 'Breaking Bad' TV series.

What I really find scary with my background knowledge from having serving on a jury trial combined with my perception of a near total lack of science education in the general population, is explaining to such 'peers' how making a small amount of HYDROGEN from water is not something so terribly bad to rot in prison. Mixing H2 and CHLORINE, to make an even small bang, would be an even more difficult task to explain.

[Edited on 13-5-2016 by AJKOER]

Fegie - 13-5-2016 at 05:56

Quote: Originally posted by AJKOER

Sulaiman:

I agree with your comments.

The last time I made a chemistry related comments to a stranger, they ask me if I made drugs! I think of this as a societal consequence of the 'Breaking Bad' TV series.

What I really find scary with my background knowledge from having serving on a jury trial combined with my perception of a near total lack of science education in the general population, is explaining to such 'peers' how making a small amount of HYDROGEN from water is not something so terribly bad to rot in prison. Mixing H2 and CHLORINE, to make an even small bang, would be an even more difficult task to explain.

[Edited on 13-5-2016 by AJKOER]

Yup, when someone you dont know too well hears you do chemistry their immediate reaction is "oh prolly drugs and explosives!"

woelen - 13-5-2016 at 09:56

You can use KI instead of KIO3. You just have to add more KOH and have to bubble more Cl2 in order to get the KI fully oxidized to KIO3.

For each iodide ion you need 4 molecules of Cl2 and 8 hydroxide ions. Add a slight excess of hydroxide and bubble some excess Cl2, so for each mol of KI, take 9 mols of KOH and appr. 5 mols of Cl2. That should give you the desired KIO4.

Sulaiman - 14-5-2016 at 21:11

Slight delay ...
I had to order a 19/26 to 24/29 adapter to connect my drip funnel to an erlenmeyer for my chlorine generator.
I tried a different setup as my chlorine gas generator, but had a small leak.
My TCCA 20g tablets arrived yesterday, much cheaper than using my NaClO.
My 15% NaClO from APC does not foam with HCl by the way.

My current plan is to use four 1" x 6" side-arm test tubes with rubber bungs and glass tubing,
anti-suckback, drier, heated reaction vessel, scrubber.
I've dropped the chlorine gas pre-heating idea ... overly complicated heating arrangement.

For today I'll just do a little more gold recovery.

EDIT: a photo of my sketch of my proposed chlorine gas generator, nothing new, just making sure I'm not missing something important.

More editing;
d) the drying agent is CaCl₂ prills
(i) is a D3/26 250ml drip funnel
I have ordered some pvc tubing as my silicone tubing is not suitable.
Not shown are afterthought pvc discs with a central hole as a protector for the rubber bungs.

[Edited on 15-5-2016 by Sulaiman]

Magpie - 15-5-2016 at 09:45

I have made dry chlorine probably about 10 times so will make some comments that may be useful:

1. I dried my Cl2 with a fritted bubbler submerged about 2" in con H2SO4. CaCl2 prills may also be adequate but I can't quantify that, and I don't know what degree of dryness you require.

2. As shown you have no system backpressure but if any is generated it may push Cl2 up through your stopcock (when open) leading Cl2 to the atmosphere. The solution to this is a p-e funnel.

3. As you have no suckback liability the first empty tube likely is not needed. I used one also but I now think it was never needed. The Cl2 is always ≥ atmospheric pressure.

4. PVC is quite satisfactory but will be degraded if the Cl2 is wet, which it is before the dryer. I used PVC as much as possible and considered it sacrificial.

5. I made shrink fits of the PVC to 5mm glass tubing by heating the PVC end in boiling water before pushing it onto the glass. These very tight connections never leaked.

6. I used 15%HCl dripped on dry TCCA per Len's method in Prepublication. This works well.

1 mole TCCA + 3HCl --> 3Cl2 + 1 mole isocyanuric acid

Have fun!

[Edited on 15-5-2016 by Magpie]

Sulaiman - 15-5-2016 at 11:04

I would like a pressure equalizing drip funnel,
and there is definitely the potential hazard of HCl being ejected by back pressure,
this was the best I could come up with, without new glassware,
these are the kind of warnings that I am hoping for... thanks

The generator is too large, potentially 70 litres of Cl₂ from 260 ml 36% HCl ... chemical warfare !

Is there a reason why I should not use 1M HCl or even less ?

aga - 15-5-2016 at 11:12

Chlorine tend to bugger lots of things up, but not fast enough to be a problem if you consider things like corks, plastic tubing etc as disposable.

In the sketch it looks like the second test-tube should be facing the same way as the first one, and have the connector tube swapped if you wanted to protect against suck-back.

A Magpie says, the chlorine pressure prevents suck-back, and that has not been an issue the few times i've tried it this way.

A non p-e addition funnel works fine, so long as you remember to keep an eye on it and keep it topped up.

Try to add the HCl drop-wise rather than getting all excited and dump a whole load in all at once !

One of the great things about Len's Cl₂ method is that the addition of HCl controls the amount of chlorine produced, so if it's too much, just stop adding HCl.

Metacelsus - 15-5-2016 at 11:41

Quote: Originally posted by Sulaiman

Is there a reason why I should not use 1M HCl or even less ?

Yes. Yields will likely be lower.

Magpie - 15-5-2016 at 11:43

Quote: Originally posted by Sulaiman

Is there a reason why I should not use 1M HCl or even less ?

15%HCl is about 4.4M according to my handbook. Len probably selected this as a practical concentration to use.

If you go down to 1M the reaction may be too sluggish. You could experiment using a test tube or small beaker.

aga - 15-5-2016 at 11:48

There's also the very important thing about Flask Volume.

If the acid is very weak, you'll quickly fill up the generator flask, mostly with water !

Sulamain's Dragon Gold

aga - 16-5-2016 at 12:37

I've decided to go ahead and copy Sulaiman's experiment.

Naturally, as an amateur, things are never so simple as 'pick up a vial of powdered gold' etc.

I have a some Gold and a rusty old file.

Iron would definitely be a contaminant, so i can't just use that old file to get gold filings.

Dunk the file in agricultural-grade phosphoric acid for 24 hrs is the answer !

Pretty gunky after even 30 mins.

After 24 hours and some washing and brushing with a steel brush, all nice and clean.
(well, as clean as i'm going to be bothered getting it)

Finally, with a Clean(ish) file i can grab the gold between a pair of pliers and file it to get smaller particles.

Ironically the file is not that old, just that quite a lot of Chlorine gas got to it the last time i did a Chlorination !

OK Sulaiman, i got 0.79g of Au all broken down and ready for chlorination.

Over to you for the next step.

Edit:

Reading what i've written, it seems silly to Not dunk it in conc HCl overnight then rinse out any remaining iron contamination.

[Edited on 16-5-2016 by aga]

aga - 17-5-2016 at 08:23

Adding some HCl was worth doing :

Funny, but i thought it'd go green due to the traces of iron, going yellowy later.

Unlikely that i've dissolved any Gold with just 20% HCl !

Sulaiman - 28-5-2016 at 09:07

My adapter arrived yesterday, today I assembled the chlorine generator, pretty much as my earlier sketch.
No experiments yet as my prolapsed disk is giving me trouble, hopefuly soon .......
on the bright side, more time to plan a couple of Cl2 experiments.

aga - 28-5-2016 at 13:58

Still hanging fire here with the Au still in the HCl.

Will wait until you're ready, seeing as it was your idea.

Sulaiman - 28-5-2016 at 21:57

please, don't wait for me, no way to know how long before I'm fit enough to continue.

Melgar - 1-6-2016 at 03:59

Make benzyl chloride, a moderately effective tear gas and a great organic precursor chemical. Bubble chlorine into toluene (xylene would probably work too, if you didn't care about further synthesis, or you actually want a mixture of 2-methyl, 3-methyl, and ortho and meta di-benzylchlorides). Toluene can actually dissolve quite a lot of chlorine, and will eventually turn yellowish-green. When it looks like the chlorine bubbles aren't fully dissolving in the toluene anymore, here's the fun part. Take a pinch of any bromide salt. Sodium bromide is available in small packets in pool stores. Add it to the mixture, and you'll see some brown stuff come off of the salt. That's bromine and bromine monochloride. If you don't notice anything else happening after a minute or two, gradually move it to brighter and brighter light sources. It should start bubbling like crazy with HCl fumes, and the green will totally disappear.

That was a free-radical-initiated chain reaction. Bromine absorbs longer wavelengths of light than chlorine does, and thus a little bit of energy from light will turn it into a free radical, where it will quickly grab a loosely-attached hydrogen atom from a nearby toluene molecule. That makes toluene a radical too, which will grab any chlorine or bromine that happens to be nearby, forming yet another radical. This chain reaction will keep going until the radicals run into each other and form a stable molecule.

You'll also notice a new smell. Well, not so much a smell as an attack on your senses. Benzyl chloride, when it comes in contact with water, forms an equilibrium between itself and benzyl alcohol plus HCl. Much fun when it contacts your mucous membranes. Anyway, if you manage to isolate a significant amount of it via distillation, you can convert it to benzyl alcohol by stirring or shaking with an alkali hydroxide solution. Benzyl alcohol smells faintly pleasant, but you've probably got enough benzyl chloride around to overpower it. (seriously, that stuff will adsorb onto virtually any polymer and then slowly release over weeks). So if you want a more pleasant smell, crack open a "Heavy Duty" carbon zinc battery, preferably one of those 6-volt lantern cells. The outsides are made out of zinc (useful for lots of stuff), there's a graphite rod in the center of each cell, (great for electrolysis when you don't want metal dissolving in your solution), and packed around each rod is the bulk of the battery in black powdery form: manganese dioxide. Take some of that stuff and mix it with your benzyl alcohol. You'll notice a nice floral smell, like vanilla or cherries. That's benzaldehyde. Congratulations, you've just made a DEA List I precursor! You've taken the first step towards becoming Walter White. Expect a knock on your door from the DEA any day now.

[Edited on 6/1/16 by Melgar]

Dragons Blood ... Started

Sulaiman - 4-6-2016 at 07:52

Feeling a bit better today, so trying first run of anhydrous AuCl3 synthesis.

Gold powder in 250 ml rbf, sand in solder pot, temperatures stabilised.

Chlorine generator and CaCl₂ drier flushed with Cl₂, 250 ml rbf flushed with Cl₂, heated for a while, flushed, 30 minutes in ...

part2

Sulaiman - 4-6-2016 at 07:54

couldn't add photo, 30 minutes in...

tbc

aga - 4-6-2016 at 08:29

cool !

Glad you're feeling better.

[Edited on 4-6-2016 by aga]

continued

Sulaiman - 4-6-2016 at 08:40

After about 1 hour at 160 C;
chlorine fainter than 100 %
gold looks brown and the mobile dust has clumped

recharged with Cl₂
temperature increased

my phone camera shows weak colours, the chlorine is quite yellow, the gold is a disappointing dark brown, and a reddish tinge on the inside of the rbf can be seen
... to be continued ... as long as it takes ....

aga - 4-6-2016 at 08:50

Lob a small stirbar in there so you can fiddle with the gold/powder.

Sulaiman - 4-6-2016 at 09:03

I don't have stir bars,
there is a hole in the rubber bung to allow for Cl₂ consumption,
so far I've resisted 'poking' the gold, going now to check progress ...

EDIT 18:10 with some tapping and bumping the mass is now mobile/powdery again.
Flushed with fresh Cl₂ , temperature increased ....

19:10 not much change but it appears as though gold + chlorine makes a volatile brown/red substance that sublimes onto the cooler part of the rbf,
possibly related to AuCl₃ disproportionation ... looks good
... getting a little impatient, 19:20 ... heating bath at 252C ...

[Edited on 4-6-2016 by Sulaiman]

aga - 4-6-2016 at 11:40

Well, you got gold(I) chloride boiling at 298 C and gold (III) chloride boiling at 254 C...

You're up at 252, which is pretty much close enough to be boiling away some of your product through the hole in the bung.

I'd drop it by 20 C or so, maybe add a condenser if possible : i.e. just a longer pipe on the flask.

More Edit:

wiki says :
"Anhydrous AuCl3 begins to decompose to AuCl at around 160 °C; however, this in turn undergoes disproportionation at higher temperatures to give gold metal and AuCl3"

So drop way back down in temperature !

(or maybe go higher: wiki doesn't say what 'higher temperatures' means.)

[Edited on 4-6-2016 by aga]

Sulaiman - 4-6-2016 at 13:34

On the assumption that the (sublimed, disproportionated ?) substance that collects on the inner wall of the rbf is 'product'
I am willing to risk a little loss in return for reaction rate.
dry chlorine seems to react very slowly with gold
(like the dry/wet nail rusting experiment ?)
I'm going to risk leaving it overnight at its present 232 C
this is the sand (now sand + NaCl as sand spilled) temperature,
I do not know what the gold temperature is.

Some sort of powder/gas mixing arrangement would help.

aga - 4-6-2016 at 13:49

Great stuff !

Experimentation as it happens !

I will definitely follow up and repeat your experiment, just as soon as i get a new, bigger extractor fan.

I'll try to do it real-time as well.

I think what you have done, real-time-wise, is a 'first' here on SM.

Sulaiman - 5-6-2016 at 11:26

Last night I left my AuCl3 reaction vessel with a fresh charge of chlorine gas in the sand bath at 232 C.

24 hours later there is very little yellow tinge from the chlorine,
the gold powder looks like gold powder again, an there is a small quantity of red deposit on the flask wall.
Here is the gold powder still in the rbf (originally 0.58g)

and after a recharge with chlorine, a view of the red stuff

Notice the gold has very quickly reacted ... on the surface only.
I hope that the red is not just decomposed rubber stopper

tbc ....

Aside;
Due to paranoia I used too much silicone grease on the ground glass joints of my chlorine gas generator
... chlorinated dribbles of silicone grease are time consuming to remove :mad:

[Edited on 5-6-2016 by Sulaiman]

aga - 5-6-2016 at 12:05

Paranoia with Chlorine is a Good Thing.

Quite often i opt to Not grease the joints simply because the reagents will eat them and contaminate the product, and being a purist ....

... or more honestly, the vaseline just dribbles into the pot, so better off without it.

IF the red condensate is actually the Product, how you gonna get it out ?

[Edited on 5-6-2016 by aga]

Sulaiman - 5-6-2016 at 13:15

I hope to dissolve the AuCl3 in diethyl ether and crystalise it from there.
If I had anhydrous ethanol I'd probably use that instead.

I've only once recrystalised from a solvent other than water, sulphur from DCM, and that was very small crystals,
I will try to evaporate slowly enough to form a visible crystal

aga - 5-6-2016 at 13:18

Ether ! Eeeek !

Am i being a bit over-concerned, or is Ether not much of a bad-ass ?

Sulaiman - 5-6-2016 at 13:36

Ether and flames is a poor combination choice
but I do not intend heating the ether,
just using a little more than necessary to dissolve any AuCl₃ in the rbf,
then transfer to a test tube for slow evaporation.

A little ether compared to the litres of chlorine gas may be so dull that I'll fall asleep

(yes, I've watched YT ether fire videos, and deliberately burned it to familiarise myself with the hazard)

Ethanol seems only a little safer,
because possibly due to assumed familiarity,
a casual approach may be more hazardous.
Anyway, I have none, and a covenant on my property means I shall not be making any.

The RBF with the gold and a fresh charge of chlorine gas, left to cook at 232C bath temperature
(nothing special about this temperature other than it seems to be working, and more variables complicate observations)

From the pattern of gold/AuCl_n surrounded by about 1cm of 'clean' glass (coinciding with the contact area of the sand bath)
then a ring of red/brown condensate,
then tiny yellow monoclinic-looking crystals
I assume that the gold is too hot for a 'simple' reaction,
but hopefuly enough yellow and red stuff will collect for me to have a go at analysing.
A poor photo

[Edited on 5-6-2016 by Sulaiman]

[Edited on 5-6-2016 by Sulaiman]

CRUSTY - 5-6-2016 at 19:05

You could always play around with some ring substitutions, ie chlorination of benzene and its derivatives, which would both use the FeCl₃ mentioned in some previous replies as a catalyst and the raw chlorine gas to perform the substitution with. You could also, although it's not a really pleasant product, attempt to synthesize thionyl chloride if you're feeling daring (REL is 1 ppm).

The Dragon is bleeding ... First Blood

Sulaiman - 7-6-2016 at 00:46

After 66 hours at around 232 C,
enough (presumed) AuCl₃ has formed to look interesting ...

It seems that I chose the wrong experiment to do a slightly delayed running commentary,
my AuCl₃ synthesis updates were a little optimistic regarding time-to-results ...
Clearly Alchemists were patient folk !

I have now reduced the bath temperature to around 210 C ......

aga - 7-6-2016 at 05:23

66 hours !

Wow. That's a lot of firewood.

careysub - 7-6-2016 at 07:21

Quote: Originally posted by aga

I've decided to go ahead and copy Sulaiman's experiment.

Naturally, as an amateur, things are never so simple as 'pick up a vial of powdered gold' etc.

In the future, anyone wanting to get gold fines should look at buying "placer gold" on-line. There are a fair number of people who pan (or sluice box) for gold as a money-making pasttime and recover fine powder so it is always available.

Sulaiman - 7-6-2016 at 08:54

After adjusting the sand bath temperature to c 210 C
I went to check that the temperature had stabilised
my solder pot control must be faulty because the temp. was off the end of my 250C thermometer,
time to repair the solder pot .....

So after the rbf with gold + product cooled down
I used diethyl ether to dissolve the product
in a small test tube two layers formed,
a deep red at the bottom and yellow at the top .... hooray !

after a couple of minutes the red layer at the bottom slowly changed to orange, like this

Product.jpg - 14kB

aga - 7-6-2016 at 12:27

Well, you chlorinated the gold and got it out of the pot, which is an achievement !

Water in the ether maybe ?

j_sum1 - 7-6-2016 at 14:35

I too would like to try this one. (In a few months when my lab is back together.)
My gold source is going to be leaf. And I think I will attempt a setup where I keep the product on the glass. Perhaps a test tube or microscope slide in a stream of chlorine.

The colour is seriously cool. And there is a bit of alchemy intrigue to this whole process.

Sulaiman - 7-6-2016 at 15:06

Now that a couple of hours since my dissapointment have passed,
and I've had something to eat and drink after the sun has set,
I'm not quite so upset

Back to the drawing board (what term do chemists use ?);

I will see what I can recover from the 'product'.
I did not check for water in my ether

I am expecting a sodium extruder soon so I'll test for too much water/violence,
then add a few sodium worms to dry it.

On the assumption that the anhydrousnes of the AuCl₃ is lost,
I'm going to re-refine all ( c1g ) of my gold to gold dust ready for the next attempt,
then my setup needs modifying;

I need ideas on how to continuously expose the maximim area of hot gold to the chlorine gas.
All I can think of at the moment is a small stainless steel propeller on a long shaft.
I do not want to generate a continuous stream of chlorine gas
due to the problem of capture.
(my chlorine generator cannot provide enough pressure for a bubbler, and a lot of gas would be required for agitation)

Would the earlier suggestion by aga of a stir bar work?
(I am going to add proper temperature control to my solder pot, so adding spinning magnets may be on the list)

P.S. using 20g TCCA and an excess (30ml) of 18% HCl requires only a small reaction vessel,
my 1l vessel holds too much chlorine for later disposal.
(just flushing 1l of chlorine gas out of the flask with water turned the brass water tap black and pink !)

UPDATE: after c70% of the ether has evaporated, the 'product' looks incredibly like HAuCl₄ aqueous solution.
Left = HAuCl₄ Right = 'product' in ether

I'll see what is left in the test tube after complete evaporation ......

EDIT: tested my diethyl ether with a small piece of sodium ... DRY.
There should have been negligible H₂O in the rbf as it was exposed to air only briefly whilst cooling and the chlorine gas is dry,
so I do not know what happened here.

[Edited on 8-6-2016 by Sulaiman]

Richard3050 - 7-6-2016 at 18:51

If you have any sodium metal you can experience the very exothermic production of salt.

chemrox - 8-6-2016 at 09:26

Has anyone mentioned choral hydrate? Cl2 EtOH H2O ..?

aga - 8-6-2016 at 13:15

Quote: Originally posted by Sulaiman

so I do not know what happened here.

Not knowing what happened is all part of the Fun !

You know for certain that Something happened, so it's a job for the experimenter in you.

The gas balloon thing worked pretty well when the S₂Cl₂ was done, so that may be a way to reduce the Cl₂ required.

Having a small stirbar in there so you can 'mess' with the reactants is not only fun/time absorbing, it does allow you to jiggle the particles about to expose fresh reactive surfaces.

Given the small scale, i suspect having smaller tube-like apparatus will be helpful, although i have no experience with this reaction, so do not know for sure.

Time to stop guessing and actually try this myself so we can compare notes.

Quote: Originally posted by chemrox

Has anyone mentioned choral hydrate? Cl2 EtOH H2O ..?

One cock-up at a time please.

Last time i tried for chloral hydrate (i.e. second time) kinda showed that the presence of any water does not give chloral hydrate, rather some dissolved mess of products, which maybe includes a bit of chloral hydrate.

As per Vogel, the aim is to chlorinate Dry ethanol to precipitate chloral alcoholate/trichloroacetaldehyde/2,2,2-trichloro-1-ethoxyethanol then dehydrate that with conc sulphuric to make chloral, then add a stoichiometic amount water to the dry chloral to get actual chloral hydrate.

Dumping damp chlorine into a pot of wet ethanol doesn't seem to work : it didn't when i tried it.

[Edited on 8-6-2016 by aga]

Turn Gold to Rust !

aga - 11-6-2016 at 08:39

Despite a poor extractor fan in my 'hood, today i just had to try Sulaiman's Dragon's Blood synth (Au₂Cl₆)

Bodging together bits of glassware gave this :-

Left-to-right there's the standard len-chlorine generator, DCCA in my case, with the gas take-off directly from the top of a pressure-equalised addition funnel.

Next is a (broken/repaired) gas wash bottle with some conc H₂SO₄ in it.

The chlorine feed then goes to a couple of vac adapters, as there was nothing else available to get the gas into the 25ml RBF where the gold is sitting.

This RBF has a stirbar and sits 10mm above the hotplate (i.e. 'airbath').

The addition funnel was charged with 100ml 20% HCl, 30g DCCA put in the chlorine generator, but not attached yet.

Heating and stirring were started and a very slight vacuum started to pull dry air thru the apparatus for 5 minutes.

Then the vac was disconnected and an NaOH inverted funnel trap fitted to catch as much 'waste' chlorine gas as possible.

The DCCA vessel was then attached and the HCl drip-feed started.

Pretty soon we have chlorine in all the glassware :

After around 5 minutes there was a noticeable colour change :

After 15 minutes the precious gold resembled Rust !

The experiement was stopped after 1 hour, by which time a rich redness was apparent in the reaction vessel :

If this is actually gold (III) chloride, what do i do with it ?

blogfast25 - 11-6-2016 at 09:00

Quote: Originally posted by aga

If this is actually gold (III) chloride, what do i do with it ?

Try and dissolve it in 12 M HCl, that should give an acidic AuCl₄^-(aq) solution.

Then carefully neutralise to pH > 4 and add a reducing agent like sodium metabisulphite. The Au should drop out as powder.

Nice set up, BTW.

[Edited on 11-6-2016 by blogfast25]

aga - 11-6-2016 at 11:10

Quote: Originally posted by blogfast25

The Au should drop out as powder.

DOH !

So all this is just to get more finely divided gold particles for the next run !

aga - 11-6-2016 at 11:25

Quote: Originally posted by Sulaiman

Last night I left my AuCl3 reaction vessel with a fresh charge of chlorine gas

Wait a sec - does that mean you stuffed some chlorine into the reaction vessel, then Stopped the chlorine flow, then left it overnight ?

aga - 11-6-2016 at 14:20

The remains in the reaction pot were washed out with water, then filtered. The solid Gold remains were weighed.

It didn't do very well : only 0.08g of the Au reacted in 60 minutes.

What to do ? Chlorinate other stuff of course !

Al foil was a bit boring, doing pretty much nothing even with heating.

Sn turnings ? Before:

After a few minutes :

Amazingly a couple of Orange Sparks were seen in the reaction pot whilst jiggling the stirbar.

Clearly one of the errors here is that not enough Tin was used and it was not dried thoroughly.

How do you get the tin chloride out of the pot if it is just a film of white stuff on glass ?

To round it off, back to a familiar chlorination : Sulphur

Maybe best to use that S₂Cl₂ up quickly, and make factice again tomorrow with linseed oil.

Certainly not going to risk losing more glassware trying to store a reagent i do not really need.

The gas generator and wash pipes have become almost white due to attack by chlorine.

The pipe on the right has been attacked by disulphur dichloride vapours.

This is why the tubing in this setup should be considered a 'consumable' : it will be discarded when the apparatus is disassembled, as it is well and truly knackered.

"How do you get the tin chloride out of the pot if it is just a film of white stuff on glass ?"

Sulaiman - 11-6-2016 at 14:33

This is exactly what I am considering for the anhydrous AuCl₃,
I think that some creativity in the 'inert atmosphere' area is required,
for the dry chlorine + gold (or tin etc.) , the dense chlorine protects the product,
until you want to extract it ...

I'm flat on my back at the moment so it is great to see your progress ... SM rules!

P.S. Love the hood ... I hope you enjoy using it.

[Edited on 11-6-2016 by Sulaiman]

aga - 11-6-2016 at 15:01

Quote: Originally posted by Sulaiman

I'm flat on my back at the moment so it is great to see your progress ... SM rules!

Sorry to hear about your horizontalism.

Glad to bring at least a modicum of succour with my random chemistrations.

Edit:

'Inert' is a relative term.

100% Chlorine atmosphere works quite well in this case.

My question is more about how to get the stuff off the glass in any useful quantity.

Maybe Gold Chloride dissolves in disulphur dichloride ...

.. then again, how would they be separable ?

Questions questions.

[Edited on 11-6-2016 by aga]

Sulaiman - 11-6-2016 at 15:36

I have CHCl₃ which may be worth a try, even if it gets chlorinated to CCl₄ it may not be a problem ?
I am working on the assumption that anhydrous AuCl₃ crystals can be grown .... that may be like trying to grow P₂0₅ crystals

I like the gold foil idea, maximum surface area exposed,
(I have read many accounts of fake gold leaf via eBay so care required)

aga; how effective do you think your chlorine trap was?

aga - 12-6-2016 at 00:08

The clorine trap works very well if you can time the chlorine production right, meaning no gas bubbles escape from the trap.

I have never managed to get it that precise, so some chlorine always escapes - more than enough to warrant a fume hood.

Perhaps a much bigger trap (e.g. a bucket and very large funnel) would give more leeway with the timing, although a significant amount of chlorine escapes anyway when you dismantle the apparatus.

Maybe best to use that S2Cl2 up quickly ...

aga - 12-6-2016 at 05:25

No, best not to make S₂Cl₂ at all.

I'd forgotten how reactive it is and how much it stinks.

A small qty was put into a tiny dram vial with a cork stopper, the foolish idea being to seal it with wax.

By the time the wax melted, the cork had been almost totally destroyed.

God awful job to clean up the mess - gas mask aboslutely Essential.

NEMO-Chemistry - 13-6-2016 at 05:37

Quote: Originally posted by aga

No, best not to make S₂Cl₂ at all.

I'd forgotten how reactive it is and how much it stinks.

A small qty was put into a tiny dram vial with a cork stopper, the foolish idea being to seal it with wax.

By the time the wax melted, the cork had been almost totally destroyed.

God awful job to clean up the mess - gas mask aboslutely Essential.

What mask do you use? i would appreciate a link if you have one. You seem to mess with some nasty things in a shed! But your alive, so i am figuring it might be worth getting a mask like yours

.

Love the shed stuff! Chlorine i would like to work with, some of the other things you do i enjoy reading about but dont fancy doing myself

aga - 13-6-2016 at 07:53

Dunno what make the mask is - some generic thing with two replaceable A1 filters, which both appear to have expired in Nov 2015 ...

Think i'll get one of those full-face masks because the sulphur chloride fumes sting the eyes quite a bit.

NEMO-Chemistry - 13-6-2016 at 08:40

Ok dopey question alert!!

Is A1 a reference to the size of molecule they filter? I just kind of figure if Mol sieves for water are known as A3 then maybe the filters for masks are numbered in a similar way?

Is the mask one of those with the cartridges on? sorry for all the questions but i dont have fume cupboard yet and a mask would be useful anyway, i am a bit of a chicken with most chemicals

aga - 13-6-2016 at 12:42

A1 filters are supposed to stop all sorts of nasty things, yet not All.

http://www.moldex-europe.com/en/service/protection-levels-ga...

Seems i should have had A2B2E1 filters at a minimum.

Heigh-ho. Exposure was only for about a minute and i feel fi ...

NEMO-Chemistry - 13-6-2016 at 12:58

Quote: Originally posted by aga

A1 filters are supposed to stop all sorts of nasty things, yet not All.

http://www.moldex-europe.com/en/service/protection-levels-ga...

Seems i should have had A2B2E1 filters at a minimum.

Heigh-ho. Exposure was only for about a minute and i feel fi ...

No prices, so they are expensive! But how much is it worth not to take risks. I have looked around for prices on masks and cartridges and its about the same as it would cost to make a reasonable fume cabinet.

So is it worth getting a mask when the worst i am likely to work with is chlorine, would i not be better off just spending the money on making a fume cabinet?

Seeing as you have both do you think a mask is a must have even with a cabinet? I am trying to work out what the best option would be, i cant afford both at once so which would you get first? I think eventually i would get both, but which would you suggest i get first?

For now all my chemistry is pretty safe, just simple extractions and things like that and i work outside most the time. Sorry to bug you with all the questions.

clearly_not_atara - 13-6-2016 at 13:03

Anhydrous CrCl3 is a catalyst for the ambient-pressure hydrogenation of magnesium (w/ naphthalene/anthracene cocatalyst) to MgH2. This may be an interesting target, as it also happens to be a pretty shade of purple.

(I realize this is from another thread, but it's cool!)

Magpie - 13-6-2016 at 13:08

Quote: Originally posted by NEMO-Chemistry

So is it worth getting a mask when the worst i am likely to work with is chlorine, would i not be better off just spending the money on making a fume cabinet?

I have a good fume hood and a good mask. I seldom if ever use the mask after I built the fume hood.

I recommend putting the money into a hood.

aga - 13-6-2016 at 13:13

A fume hood makes working with nastier smelly/lethal gases easier.

I would say you'd need a Gas Mask before a fume hood, even if working outside - the wind changes direction !

A gas mask is Not adequate protection for many things, so do not assume it will save you in All circumstances.

When everything goes wrong (e.g. vessel explodes, shatters fume hood glass etc) it helps to be able to keep breathing, so definitely a gas mask before a fume hood.

Once you have a fume hood, keep the gas mask handy (and up to date).

NEMO-Chemistry - 13-6-2016 at 13:42

Conflicting advice so, make a fume hood because they are cool and because i hate the smell of solvents! Leave Chlorine until i have both! Seems like a reasonable compromise.
I see the point about wind changes etc, i also except Magpies input. So little point taking chances until i have both, also my knowledge level is low so best stick with the basics for now.

I have a few other questions but dont want to hijack this thread so will post them elsewhere. Thank you though for the advice.

aga - 13-6-2016 at 14:00

Fire away.

I suspect we already tried what we wanted to try, so free space here as it were.