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bismuthate
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Sorry I meant the copper complex of iodate. I was kinda talking to myself. Sorry
http://woelen.homescience.net/science/chem/exps/CuIII/index....
Here's a synthesis.
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Oscilllator
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Because it didn't have a precipitate yet, silly.
--
An update on my molybdenum blue efforts: I have managed to get a precipitate using hydrolysed sucrose, so all that remains is to filter it, although
characterisation will be difficult (anyone have a reference that uses an aldehyde as a reductant?)
I don't know about the use of thiosulphate as a reductant though. Since thiosulphate reacts with acid to give elemental sulfur, the end product will
as such be contaminated. If anyone wants to enter a molybdenum blue synthesis that uses thiosulphate, I think that they should have to demonstrate
that they have removed any elemental sulfur. This will be extremely difficult, because the sulfur particles formed are extremely small and nearly
impossible to filter in my experience.
With regards to the morals of synthesising Molybdenum blue however, I think it is a perfectly fair target because isolating the compound in its pure
form is very difficult. Added to this is that I understand there are a number of different similar molybdenum blue compounds, and so the only way you
can be reasonably sure you have one of them is if you follow an established procedure and achieve the same results.
But I think Aga sums it up nicely:
P.S. Don't worry Aga, I'll post my results and method regardless of whether or not I win the competition.
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bismuthate
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Well feel free to make one of them if that's you opinion. Also I used too little acid and the reaction was immediate so no sulphur could have formed.
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aga
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Well, my Barium Periodate dribble dried out overnight into a fine white powder.
It was windy this morning, and it blew away.
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bismuthate
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Oh well. I'll accept it
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blogfast25
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Quote: Originally posted by Oscilllator  |
With regards to the morals of synthesising Molybdenum blue however, I think it is a perfectly fair target because isolating the compound in its pure
form is very difficult. |
Not from what I've read: they just mixed the chemicals, allowed to stand for 3 days, filtered and washed.
Re. thiosulphate: if the reduction reactions are much faster than the sulphur formation (I believe that is true), sulphur contamination should not be
a problem, as all the thiosulphate will preferentially react away in the reduction reactions. I've titrated with thiosulphate in acid conditions w/o
any sulphur formation.
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bismuthate
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Yup. That was my reasoning for why there would be no sulfur. Plus I used les than the amount needed. Of the HCl that is
[Edited on 26-11-2014 by bismuthate]
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blogfast25
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I had made this lovely HMW compound, a wonderful green it was but Freddy the Duck ate it. Can I submit too? 
[Edited on 26-11-2014 by blogfast25]
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bismuthate
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Yup.
Just kidding.
But I'm accepting his because I saw the pic earlier.
[Edited on 26-11-2014 by bismuthate]
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Texium
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Yeah, really since it wasn't as heavy as the current frontrunner anyway, the rules don't need to be so strict. Only on compounds that are challenging
the current heaviest one. I think I'll make a publicly viewable Google doc with the current leaderboard.
Edit: Here is the link: https://docs.google.com/document/d/1XSsPWkPlc9ZYOOliBgl4HP9p...
Still actually only 4 entries currently
[Edited on 11-26-2014 by zts16]
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aga
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As ever, Aga is the Four runner.
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deltaH
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If moly blues are allowed, then it's not necessarily a guaranteed win, because there are MANY compounds in that class, some with very high molecular
mass and others, less so. It can still be very much a contest and I am sure we have not seen the end of moly blues here.
For those who have struggled to obtain moly blue crystals... they take a very long time to crystallise (some big ones... 2 weeks while covered),
simple because of the size of the things, it's a kinetic issue... but crystallise they certainly do and without the need to do anything fancy. In
fact, they crystallise so well that one can perform single crystal x-ray diffraction (to prove its structure) on an individual crystal, as was done in
one paper I read with one version of a moly blue on the high end side (MW between 50000 - 100000... not saying exactly in case someone intends to
enter that particular one).
That said, as I've written about earlier, I personally don't think moly blues should be allowed under the original rules because it's an inorganic
macromolecular polymer by IUPAC definitions (since it is made up predominantly of a molybdate monomer).
Yet, I think under the spirit of all-things-groovy, moly blues might be declared fair game by the powers that be 
That's half the fun of such a contest... who knows
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bismuthate
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Ammonium Phosphomolybdate
1876.35 g/mol
(NH4)3PMo12O40
First prepare a 8M solution of Nitric acid from nitric acid made from ammonium nitrate and sulphuric acid.
Pour 40mL into a beaker.
Dissolve 3.5g of sodium molybdate (fertilizer) in this.
Dissolve 5g of hardware grade TSP in it.
Prepare a solution of 3g of ammonium nitrate cold pack beads in 20mL of water.
Mix the two solutions.
Heat it.
Filter and dry the rather beautiful yellow precipitate.
12(NH4)2MoO4 + H3PO4 + 21HNO3 ==>(NH4)3PMo12O40 + 21NH4NO3 + 12H2O
https://www.dropbox.com/s/vuxozjjsaj9jfjo/Photo%20Nov%2029%2...
https://www.dropbox.com/s/c1hlk3wy6dvaya8/Photo%20Nov%2027%2...
https://www.dropbox.com/s/uzag4yr6ahysir1/Photo%20Nov%2022%2...
sorry about poor pic quality. My lighting sucks.
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Texium
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Nice job! The color of it reminds me of cadmium sulfide. It seems like your procedure and product are completely legit this time, so it looks like
with that you're currently in the lead.
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unionised
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Surely I'm not the only one looking at that and thinking of the next row of the periodic table?
http://www.endmemo.com/chem/compound/nh4_3w12po403h2o.php
A heavier counter-ion and you could break the 3000 mark.
Incidentally, if anyone tries this starting with tungsten metal and dissolving it in molten NaOH/NaNO3 please beware that the reaction is rather
violent.
Also if you ppt the WO3. n (H2O) with acid, remember the NOx fumes are nasty
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Texium
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Yep, I was just looking at that too.
I have something better though, if I can pull it off in the next week or two.
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Brain&Force
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Aren't we going to have weekly/biweekly updates in the thread regarding the current winner and prize?
At the end of the day, simulating atoms doesn't beat working with the real things...
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Texium
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We should, but Praxichys seemed to be the one doing that, and he seems to have mysteriously disappeared...
As of today, the competition is halfway over.
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Brain&Force
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I think that's his trademark he's done that in several other threads.
[Edited on 1.12.2014 by Brain&Force]
At the end of the day, simulating atoms doesn't beat working with the real things...
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Praxichys
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Haha, I suppose it is.
Sadly, chemistry is only my hobby, and I am often very busy with things like fixing the house, tending to the lady, business travel, etc. and I do not
always have time to respond or follow things up at the speed I would like. With the recent holiday, things have been especially crazy. Many of you
probably noticed that I have been quite absent from Skype for the last week, and the TEMPO synth that I am working on is at a TEMPO-rary standstill.
(Ha!)
I do read SM daily, and although my focus on chemistry (and video making) will continue to come in bursts, I have no plans to quit. I will try to be
on Skype tonight!
The pot is now $24.
Oh, and if there is money involved (or shipping things), it will happen on time, guaranteed. Those things have much higher priority than
simple discussion. I think the 30-ish people here who ordered mercury can testify to that.
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blogfast25
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Surely not. It's been discussed above: the P12WO3 compounds. I was going to prepare the barium hydrate of it but to me the Moly Blues should
rightfully win, so I won't be entering anything.
I think Bismuth hasn't made enough of the compound, by the rules?
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bismuthate
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It was over .5g so it passes and anybody could still submit a molybdenum blue if they want.
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unionised
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Unless someone can convince me otherwise I think that the molybdenum blue is a polymer (and a poorly defined one at that.)
I can't see how anyone is going to meet the requirement of this rule
"You must have the exact molecular weight."
with the sort of mess you get from Mo Blues and such.
It may well be mainly the "big wheel" but what evidence is that that you don't have a whole mess of impurities?
However, I don't really care- I'm not entering, just puzzled as to how someone intends to measure the degree of polymerisation.
[Edited on 1-12-14 by unionised]
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Mesa
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I can't say much for Mo compounds as I've had no reason to study them, but many of the W compounds can be isolated or prepared in a relatively pure
form.
[Edited on 1-12-2014 by Mesa]
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blogfast25
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| Quote: Originally posted by unionised |
1. Unless someone can convince me otherwise I think that the molybdenum blue is a polymer (and a poorly defined one at that.)
2. I can't see how anyone is going to meet the requirement of this rule
"You must have the exact molecular weight."
with the sort of mess you get from Mo Blues and such.
It may well be mainly the "big wheel" but what evidence is that that you don't have a whole mess of impurities?
3. However, I don't really care- I'm not entering, just puzzled as to how someone intends to measure the degree of polymerisation.
[Edited on 1-12-14 by unionised] |
1. I don't think it's a polymer. Look at the formulas that describe it. It's similar but not exactly a polymer, IMHO...
2. How is anyone going to prove their compound is the exact molecular weight? No one is, Mo Blues or other.
You claim the Mo Blues are a "sort of mess". That's not what I've read at all.
3. That's point 2. really. If someone prepared Ba P12WO3 hydrate would we believe his claims for MW? How would he prove it? How about degree of
hydration for instance?
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