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Mailinmypocket
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[*] posted on 27-2-2014 at 07:28


Try fiberglass insulation maybe?
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Zyklon-A
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[*] posted on 27-2-2014 at 07:58


Yeah, I thought about that, fiberglass isn't made out of pure silicon dioxide, more like SiO2, Al2O3 B2O3, MgO ect.



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[*] posted on 27-2-2014 at 08:26


For all I know, pure cellulose filter paper will withstand nitric acid, even with sulfuric acid present. At the amount of sulfuric acid you specify, I doubt that a nitration reaction would occur. If the precipitate if very fine, it might clog the filter quickly and slow the filtration down to a crawl. A large funnel with a decent wad of cotton may suffice for a first filtration. Then you could filter the remainder with filter paper.
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Zyklon-A
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[*] posted on 27-2-2014 at 10:24


That's a good idea. Or I'll pour off the top liquid though filter paper, and avoid the precipitate altogether.



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[*] posted on 27-2-2014 at 18:20


I have household ammonia with surfactants. What exactly are the surfactants, and how will they affect complexation and precipitation reactions?
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[*] posted on 27-2-2014 at 19:25


Howdy - I want to obtain a sample of the air (pollutants - smoke to be specific) to forward on for analysis. What is the best way to capture and transport a sample? Cheers
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[*] posted on 27-2-2014 at 20:03


What brand of ammonia do you have? You can just look up the msds to find out, but IIRC its probably some benzalkonoium chloride or other quaternary ammonium salt. As to how they might affect your reactions, its hard to say. They are phase transfer catalysts and could screw up a reaction, or do nothing. Best bet is to buy some lab grade ammonia or go to a hardware store and try to find unscented pure ammonia.
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[*] posted on 27-2-2014 at 20:45


Quote: Originally posted by ZIGZIGLAR  
Howdy - I want to obtain a sample of the air (pollutants - smoke to be specific) to forward on for analysis. What is the best way to capture and transport a sample? Cheers


Fill a bottle with water. Dump it out where you want to collect your sample of air. Seal the bottle.




Please remember: "Filtrate" is not a verb.
Write up your lab reports the way your instructor wants them, not the way your ex-instructor wants them.
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ZIGZIGLAR
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[*] posted on 27-2-2014 at 21:10


Quote: Originally posted by DraconicAcid  
Quote: Originally posted by ZIGZIGLAR  
Howdy - I want to obtain a sample of the air (pollutants - smoke to be specific) to forward on for analysis. What is the best way to capture and transport a sample? Cheers


Fill a bottle with water. Dump it out where you want to collect your sample of air. Seal the bottle.


So just empty the water out (upside down) and immediately seal once the water is evacuated?
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DraconicAcid
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[*] posted on 27-2-2014 at 21:18


Quote: Originally posted by ZIGZIGLAR  
Quote: Originally posted by DraconicAcid  
Quote: Originally posted by ZIGZIGLAR  
Howdy - I want to obtain a sample of the air (pollutants - smoke to be specific) to forward on for analysis. What is the best way to capture and transport a sample? Cheers


Fill a bottle with water. Dump it out where you want to collect your sample of air. Seal the bottle.


So just empty the water out (upside down) and immediately seal once the water is evacuated?

Yep. As the water leaves, air rushes in to replace it. Seal it, and your sample is prevented from mixing with air in other locations.




Please remember: "Filtrate" is not a verb.
Write up your lab reports the way your instructor wants them, not the way your ex-instructor wants them.
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Panache
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[*] posted on 28-2-2014 at 05:12


What is the standard method for obtaining a consistent mixture of two pressurised gases, obviously both flows are regulated, then a mixing chamber of sorts, is then followed by a further regulator.
The question stems from my concern that back pressure in the mixing chamber affects both initial gas regulators and one has a system where if an adjustment is made on one regulator you end up spending ages tweaking the other.
My two gases are lpg( propane) and dried compressed air




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Oscilllator
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[*] posted on 28-2-2014 at 17:07


Quote: Originally posted by Panache  
What is the standard method for obtaining a consistent mixture of two pressurised gases, obviously both flows are regulated, then a mixing chamber of sorts, is then followed by a further regulator.
The question stems from my concern that back pressure in the mixing chamber affects both initial gas regulators and one has a system where if an adjustment is made on one regulator you end up spending ages tweaking the other.
My two gases are lpg( propane) and dried compressed air

Looking up how an oxy acetylene works will answer your question, since thats exactly what your talking about. One thing that oxy-acetylenes dont have that you mentioned is a regulator after the mixing chamber. It goes directly from mixing chamber to nozzle.




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Zyklon-A
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[*] posted on 28-2-2014 at 18:11
Question:


In an alloy, is the melting point conserved?
For example, if you alloy 3 parts copper(MP=1084°C x 3 parts=3252,) 5 parts nickel (1455°C x5 parts = 7275,) and 1 part silver (= 961°C.) =11488 ÷ 9 parts = 1276.44°C. So would that be the melting point of that an alloy. I don't intend on making such an alloy, just wanted to know.
[EDIT, just realized, it would have to be relative kelvin scale right?]

[Edited on 1-3-2014 by Zyklonb]




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elementcollector1
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[*] posted on 28-2-2014 at 18:47


Nope. Alloys, like eutectics, usually have lower MP's than their respective constituents, and I don't think it's an average.



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Zyklon-A
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[*] posted on 28-2-2014 at 18:53


Oh, that's interesting. So, is NaK an alloy then, I always thought it was a compound.




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confused
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[*] posted on 28-2-2014 at 19:05


yes, NaK is an alloy
http://en.wikipedia.org/wiki/NaK
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Panache
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[*] posted on 2-3-2014 at 14:31


Quote: Originally posted by Oscilllator  
Quote: Originally posted by Panache  
What is the standard method for obtaining a consistent mixture of two pressurised gases, obviously both flows are regulated, then a mixing chamber of sorts, is then followed by a further regulator.
The question stems from my concern that back pressure in the mixing chamber affects both initial gas regulators and one has a system where if an adjustment is made on one regulator you end up spending ages tweaking the other.
My two gases are lpg( propane) and dried compressed air

Looking up how an oxy acetylene works will answer your question, since thats exactly what your talking about. One thing that oxy-acetylenes dont have that you mentioned is a regulator after the mixing chamber. It goes directly from mixing chamber to nozzle.


Thanks so much Osc, that's an excellent example for me to refer to!. Also in my post I had punctuated incorrectly and forgetten the '?' after '...is then followed by a further regulator.' So now I can forget about whether this was the issue (edit-just looked up the wiki page on oxy/act, and my problem has an answer, rather obvious I didn't have a needle valve after the lpg regulator, thnx again)

That said I however have a further question.
Question Prologue
I have long gone by the assumption that vessels and associated piping etc designed to withstand pressure of any reasonable degree (~100psi-ish) can withstand full vacuum (well like 75torr).
This assumption generally holds also for o-ring seals and flanged seals, but I tend to decide upon it on a seal by seal basis (some seals to perform require fish).

Actual Question
Is this assumption generally safe and valid?

(The reason I ask is I was curious as to what would happen if I place a full bottle of liquid CO2 into my ultra-low freezer at -85. Liquid CO2 has a density half that of the solid and I was concerned regarding the integrity of the cylinder. I have since decided there was no real reason for doing it but it made me realise I have never questioned this assumption)

[Edited on 2-3-2014 by Panache]




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Panache
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[*] posted on 2-3-2014 at 14:38


Quote: Originally posted by DraconicAcid  
Quote: Originally posted by ZIGZIGLAR  
Quote: Originally posted by DraconicAcid  
Quote: Originally posted by ZIGZIGLAR  
Howdy - I want to obtain a sample of the air (pollutants - smoke to be specific) to forward on for analysis. What is the best way to capture and transport a sample? Cheers


Fill a bottle with water. Dump it out where you want to collect your sample of air. Seal the bottle.


So just empty the water out (upside down) and immediately seal once the water is evacuated?

Yep. As the water leaves, air rushes in to replace it. Seal it, and your sample is prevented from mixing with air in other locations.


Won't the water rushing out scrub the smoke coming it. An empty large plastic syringe (vet supplies horse size one) I would have thought more appropriate), or pull a full vaccum on a 9kg (bbg gas size) cylinder and then open it if you require a larger sample). Whatever happens the walls of the vessel will absorb or adsorb some of the smoke. I think the standard method is to suck through very fine ashless or glass filter paper a known volume of the smoke filled air, trapping the particulates and then analysing those through various really tedious and careful analytical techniques.




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[*] posted on 2-3-2014 at 16:48
Deleted video


Does anyone know what method was used in this video? Nurdrage made a video on isolating potassium from hydroxide and Mg. The video was deleted, from the comments, it seems like the reaction used a catalyst, and occurred, dissolved in some inert liquid. Sounds, a lot like Make Potassium (from versuchemie.de).



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[*] posted on 2-3-2014 at 17:18


The catalyst is a tertiary alcohol (he used amyl alcohol), which was dissolved in a high-boiling hydrocarbon (he used tetrahydronaphthalene). I believe it was the same method as Pok's.



At the end of the day, simulating atoms doesn't beat working with the real things...
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Zyklon-A
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[*] posted on 2-3-2014 at 17:31


Ok, does anyone know of a video pertaining to this method?



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[*] posted on 2-3-2014 at 17:34


Unfortunately, his (NurdRage) was the only one I know of.
Odd that of all his videos, the potassium ones in particular were deleted. Too many k3wls?




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Zyklon-A
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[*] posted on 2-3-2014 at 17:41


Too bad I didn't get to see it, I was too damn late.:mad:



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[*] posted on 2-3-2014 at 19:05


NurdRage also took down his magnesium-silver nitrate flash powder video.

I miss him a lot. :(




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[*] posted on 3-3-2014 at 05:21


I have a bottle of 'gelcoat restorer' that is usually used on fibreglass boat's.

The only MSDS I could find online lists the following contents(but not concentrations):
Hydrochloric acid
polyethylene glycol mono-p-nonylphenyl ether
water

The side of the bottle says it contains 680g/L hydrochloric acid, and given the colour/viscosity, I'm assuming the polymer is a fairly low molecular weight.

I have 2 questions regarding this;

-If I were to distill, would the polymer potentially come across with the HCl/H2O?

-Given the much higher acid concentration/lower water content, is there any possibility of using this product as-is as an acid catalyst in simple esterfications?

Edit: at current concentration, the liquid doesn't fume at all and only has a faint odour.

[Edited on 3-3-2014 by Mesa]
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