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garage chemist
chemical wizard
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Registered: 16-8-2004
Location: Germany
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I also got my MAP Pro cylinders and they indeed have a connection that does not fit onto anything that's being sold in Germany.
Good to hear that you found a supplier for a torch, woelen. I will see whether I also have to buy this.
[Edited on 19-6-2013 by garage chemist]
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bfesser
Resident Wikipedian
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<strong>Magpie</strong>, Is that a copper drain line? I've never seen copper used for drain lines in my area. That would hold up to
solvent 'recycling' much better than the PVC which is common here!
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Magpie
lab constructor
Posts: 5939
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Mood: Chemistry: the subtle science.
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Quote: Originally posted by bfesser  | | <strong>Magpie</strong>, Is that a copper drain line? I've never seen copper used for drain lines in my area. That would hold up to
solvent 'recycling' much better than the PVC which is common here! |
Yes, it's 1.5" copper. My house was built in 1965 when copper plumbing was commonly installed. I also have oak floors  .
I understand that ABS (black plastic) is commonly used for drain lines now.
The single most important condition for a successful synthesis is good mixing - Nicodem
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woelen
Super Administrator
Posts: 8013
Registered: 20-8-2005
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Yes, this is what I have, but for a lower price. I was really impressed by the prices of the Greek company. Not only the regulator and torch have
amuch lower price, but the MAP/Pro cylinders also are much cheaper (leass than EUR 10 incl. VAT). The only thing is that you need to combine multiple
items in a single order, otherwise shipping cost is very high, relative to the value of the products.
@Plante1999: I indeed want to do experiments with the gas. Next weekend I first will play around with basic stuff like adding Br2 or Cl2 to the
molecule, but the propylene oxide experiment also sounds quite nice. Another experiment I have in mind is making acrolein, using certain metal oxides
as catalyst for the reaction.
Polymerization is another possibly interesting thing, but you wrote this is very hard to achieve. I'll have to read more about this process before I
do any experiments with that.
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woelen
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I did a first experiment with Br2. I slowly bubbled propene through Br2, until the liquid does not become lighter anymore. The reaction is very
exothermic, while I bubbled in propene, I kept the test tube under running tap water.
The resulting liquid has a pleasant sweetish smell. It does not become totally colorless, a clearly visible chocolate-brown color remains. I think
this is due to some impurity in the Br2.
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AndersHoveland
Hazard to Other Members, due to repeated speculation and posting of untested highly dangerous procedures!
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What about a radical chlorination? wonder what the yields of 3-chloropropylene would be.
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woelen
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I think they yield would be very low. As soon as Cl2 comes in contact with propylene, it adds to it. If excess Cl2 were used, then I can imagine that
further chlorination occurs.
I now suddenly also think that in my little experiment of yesterday, part of the bromine went into further bromination. First 1,2-dibromopropene is
formed, but I had excess bromine in the first part of the experiment. The excess bromine may have further brominated the alkane. During the
experiment, I noticed formation of quite some white fumes with pungent odour, forming at the open end of the test tube. I was wondering what this
could be, but of course this must be fumes of HBr, reacting with water vapor in the humid air.
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plante1999
International Hazard
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If bromine really reacted with a brominated alkane, it ether means there was a lot of light when you done it, or the cooling was really inefficient.
In my experiments, the only smell I got was a sweet smell.
I never asked for this.
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woelen
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I had a thick plume of white fumes, getting out of the test tube. The test tube also became frosty near the rim, a typical thing when fumes of HCl or
HBr are produced. I had bright TL-light during the experiment and the test tube was quite hot (near the boiling point of Br2). I'll retry my
experiment tonight with purer Br2.
I have two questions for you:
1) Did you get a colorless liquid or remained your liquid brown as well, even after adding excess propylene?
2) Did you have visible fumes of HBr?
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plante1999
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1) It made a colorless liquid with excess propylene. The last bit from slightly red to colorless take 5 min.
2) I din't had any visible fumes of HBr
I never asked for this.
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woelen
Super Administrator
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I did the experiment with another sample of bromine and with this I got a perfectly colorless liquid and only a small amount of white fumes. The
liquid I obtained was non-flammable and also has low volatility.
I found out that one of my two bottles of bromine is totally spoilt. The cap has become a big blister inside and a dark brown tar-like substance has
flown into my bromine  That was the reason for the crappy result of my first
experiment.
Luckily my other bromine still is in perfect state (see picture on wikipedia) and it gives perfect results.
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vmelkon
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| Quote: Originally posted by vmelkon | | I checked and looks like I have an old cylinder of MAPP gas (propyne and propadiene). What interesting experiments can be done with it? If I pass the
gas through some KMnO4, would propyne turn into a diol? |
If anyone is interested, I tried the experiment on a very small scale.
In a test tube, made a 1 mL solution with KMnO4. I push some propyne in. I put the stopper on and shaked it. The purple color goes away and you get a
clear liquid. The cloud of MnO2 conglomerates and forms chunks of MnO2.
http://www.chemistry.ccsu.edu/glagovich/teaching/311/content...
According to that link, it would produce acetic acid and CO2. The propyne gets cleaved. I smelled it to see if I would detect from acetic acid but
could only smell the MAPP gas.
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plante1999
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Isopropyl alcohol synthesis
The synthesis of isopropanol from propylene and water, using various catalysts. The production of isopropanol is now one of great importance, for its
many industrial uses, including isopropyl ether, isopropyl acetates, and various amines. In 1990, isopropanol was the 48th most produced chemicals.
Isopropyl ether is used as an industrial extraction solvent, much like ethyl ether in a laboratory. Isopropyl acetate is a solvent used in cellulose
related industrial process, such as the paper industry. The various amines are used as bases with higher boiling point then ammonia, but much lower
than inorganic bases.
The fallowing experiment was divided in three parts:
Part 1:
Demonstration of isopropyl alcohol formation by sulphuric acid catalysed hydratation of propylene
Part 2:
Synthesis of 91% isopropanol by sulphuric acid catalysed hydratation of propylene
Part 3:
Direct synthesis of 85-90% isopropanol via phosphoric acid solid state catalyst
----------------------------------------------------------------------------
Part 1
To 3 ml of 96-98% sulphuric acid is added 0.5ml of distilled water to make a 80-85% sulphuric acid solution. The solution is placed in a sturdy glass
test tube.
On the propylene cylinder outlet, a rubber tube is connected and the a glass tube inserted in the other end of the rubber tube. The glass tube is
placed in the sulphuric acid.
A small flow of propylene is passed in, an regulated so no propylene comes out of the sulphuric acid. After a certain time, some propylene will come
out of the solution, at this point, stop the propylene flow and remove the glass tube from the sulphuric acid.
Add 10 ml of distilled water to the sulphuric acid, and a few crystals of potassium dichromate, shake well. Within a few second, the solution turn
green.
The green color prove the presence of an easily oxidized group, which can only come from isopropyl alcohol formed.
Explanations
When propylene is passed in the concentrated sulphuric acid, it form isopropyl hydrogen sulphate, 1 propyl hydrogen sulphate is not formed in large
enough quantity to be a real product due the Markovnikov's rule, group will attach to carbon atoms with more carbon-carbon bonds.
When water is added, the sulphonate is hydrolysed to isopropanol and sulphuric acid, one could distill the formed isopropanol azetrope to get usable
isopropanol, see part 2.
The dichromate, in acid condition will oxidize the hydroxy group to make the ketone, acetone. When dichromate is reduced, it makes chromium III, which
is green or purple, depending on the condition.
A interesting addition migth be to mention that the isopropyl hydrogen sulphate made when the proplene is passed in the sulphuric acid can directly be
used in synthesis, for example to make sodium isopropyl sulphate.
Pictures added soon.
I never asked for this.
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woelen
Super Administrator
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Good to see you here again!
A good check for the presence of isopropyl alcohol is simply smelling the test tube. This alcohol has a very specific smell and is nearly non-toxic,
so you can safely smell it.
Doesn't dichromate oxidize propylene directly. A counter experiment would be to bubble some propylene through an acidified solution of a dichromate
(e.g. 50 mg K2Cr2O7 dissolved in 3 ml of 1 M H2SO4). If this indeed changes color from orange to green or greyish/purple, then your experiment is not
conclusive. Smelling is conclusive, the smell of isopropyl alcohol cannot be mistaken.
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plante1999
International Hazard
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I tried to use a more appropriate scientific test, but it did smelled slightly isopropanol, take not that I have a very bad smelling sense. If
propylene is directly oxidized, it would make directly propylene glycol, it might be an interesting experiment, however I highly doubt propylene is
soluble without reaction in the medium.
I never asked for this.
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