The Short Questions Thread (4)

Quote: Originally posted by gdflp

When did he say that? I think by "lower concentrations" he meant 20%, though I could be wrong.

Quote: Originally posted by No Tears Only Dreams Now

Quote: Originally posted by gdflp   When did he say that? I think by "lower concentrations" he meant 20%, though I could be wrong. I mean, I don't see any reason why it wouldn't work. Depending on the solubility of methyl ethyl ketazine in water you might lose more of your product in the end. You could always add a base to the ammonium hydroxide solution you have and heat it, driving out the ammonia and channeling it into some freezing cold ammonium hydroxide solution that you already have, in order to increase the concentration.

Hi Folks,

What do you think this device did in its good days? I scavenged it from a closed analytical lab. The shiny part at the end looks like gold to me)

Thanks for your help!

Quote: Originally posted by AlphaDecay

Any ideas for a easy aquiring/homemade selective membrane for a potassium chloride electrolytic cell to make potassium hydroxide? I've tried gelatin but it came off from the PVC pipe that connects the two half-cells.

Would the aldehyde be an oxidizing agent? I was hoping a reaction like the following would happen. Maybe the equilibrium could be driven by the addition of sulfuric acid? (Sorry about the terrible picture)

Quote: Originally posted by bismuthate

So for amphoteric hydroxides like Cr and Cu what would happen if you attempted to react them with NaOH? Would they form Chromate/chromite or cuprate and release ammonia or what would happen?

Quote: Originally posted by bismuthate

Yes but what would happen if I tried to dissolve the ammonia complexes of the hydroxides in base?

Quote: Originally posted by Cheddite Cheese

Is your solution acidic or basic? Do you have to use nickel? Why not glass?

Quote: Originally posted by gdflp

This page lists an LD50. I don't think it has many other hazards, I'm guessing the toxicity will be very similar to that of another insoluble copper compound such as copper carbonate.

Quote: Originally posted by Cheddite Cheese

It's probably potassium iodide and potassium iodate (through disproportionation).

Quote: Originally posted by Cheddite Cheese

You probably didn't.

Quote: Originally posted by Jylliana

Can Sulphur (S8) in water be flushed down the drain or should it be stored and given to a special waste processing facility?

Quote: Originally posted by hodges

...I've also heard that it is possible to get nitrates (with small yield) by electrolysing ammonium salts...

Zn amalgam questions

Quote: Originally posted by greenlight

I think you need a catalyst to aid the reaction. Here's a link to a patent using Zinc oxide as a catalyst: http://www.google.com/patents/US3040095 Also, here's an old thread that has a synthesis of Acetamide from Ethyl acetate and Ammonia: http://www.sciencemadness.org/talk/viewthread.php?tid=23491

Thanks

But I'm still worried, as in the first link, they also mention heat and very high pressure - is that really necessary (high pressure)?

Thanks!

Quote: Originally posted by greenlight

On looking at the patent a second time it does appear to be a bit more complicated than the backyard lab unless you have a heating source to heat a vessel to 250 Degrees Celcius and a vessel or stainless steel "bomb" capable of handling 1000 psi pressure as it says here: "The acetonitrile, water and zinc acetate are mixed in ice a closed vessel and heated to a temperature of 250 C., preferably 240 C. As the heating proceeds, the pressure rises. During the initial stages of the reaction, the pressure may reach as high as 1,000 p.s.i.g., preferably about 700 p.s.i.g. Thereafter, as the reaction proceeds, the pressure falls due to the formation of acetamide which has a lower vapor pressure than acetonitrile and hence as acetamide is formed, the pressure drops. The pressure at the conclusion of the reaction is usually from 40 to 50 p.s.i.g. " I think the best way to go would be to obtain some Ethyl acetate and use the method posted in the thread link by Polesch which uses 9% Ammonia as it looks like less of a headache. The Ethyl acetate can be synthesized and the 9% Ammonia should be easy to get. I have read that ethyl acetate is the primary solvent in non-acetone nail-polish remover but a distillation would be necessary. Otherwise, here is a two links to a method of making Ethyl acetate from concentrated Sulphuric acid, ethanol and glacial Acetic acid: https://www.erowid.org/archive/rhodium/chemistry/ethyl.aceta... https://sites.google.com/site/mutludemirel/organic-chemistry... There is also a video on youtube here: http://www.youtube.com/watch?v=cFxZ0NircIk Hope that helps. [Edited on 22-11-2014 by greenlight]

Thanks, sure it helps

I have no "bomb", that would hold 1000psi/70bar But maybe I could try the way you've mentioned, I have very small amounts of conc. H2SO4 (only few milliliters), so making it wouldn't be an option, but I could try finding non-acetone nail polish remover, but how do I know that it has only ethyl acetate and not acetone or other solvents? Do you think it should be written on the bottle - I have small bottle of nail polish remover, but it says it does contain acetone, ethanol and a load of other solvents (this seems to be a problem)

Here is a picture of the bottle:





PS: even if I find NPR with ethyl acetate - there may be other additional solvents with lower BP than ethyl acetate, so there could be distillation problems, or not?

Thanks

[Edited on 22-11-2014 by xfusion44]

Thanks very much

Unfortunately I don't have fractionating column :-/

I will try to get non-acetone polish remover ASAP and will distill it and see what happens. Hopefully I'll be able to maintain the temperature under 78°C, althouhg some of ethanol may come with EtOAc too, I think it's worth a try. Do you think that ethanol would be a problem in this reaction? I looked up on internet and found out that ethylamine could form when ammonia is mixed with ethanol, but only at high temperatures (200°C) and with catalyst, so maybe it won't be a problem?

Also, do you think, that it would work fine if I'd use pure NH3 instead of solution? I could make it with NH4Cl + NaOH + H2O, although I don't know if that is effective way, to produce enough ammonia gas?

Thanks again

[Edited on 23-11-2014 by xfusion44]

@greenlight

Damn :-/ I probably bought useless nail polish remover... At first I saw that it said on the bottle butyl acetate and thought "that's it!" Then I noticed, when I checked again that I was thinking wrong, because I thought it was ethyl acetate... Then I bought it and you said I could give it a try, and now, when I'm at home I noticed that on the end of text it says acetone too Maybe I can still get only butyl acetate from it by careful distillation, but even then, the question remains: will it work with butyl a.?...

Thanks for previous question, I'll see, what I can do...

When you say non acetone NPR, do you mean that acetone would react with ammonia to form other byproduct?

It's funny that all of the time, when we were mentioning not to go above 78°C, I thought that's for preventing ethanol from distilling, but I remembered that it's the acetone that has 78°C boiling point - so if I'd have non acetone NPR I wouldn't need to worry about going above 78°C, I think? Were we both confused?

Thanks

[Edited on 23-11-2014 by xfusion44]

Quote: Originally posted by arkoma

Here in the states "MEK substitute" at home depot=ethyl acetate. Five bucks a quart.

Quote: Originally posted by greenlight

I said to distill non-Acetone nail polish remover because they substitute the acetone with Ethyl acetate, the product you need to make Acetamide. It may be harder to find the acetone free polish than the normal acetone brand. I did mean not to go over 78.C because the non Acetone nail polish remover also has Ethanol in it which has a boiling point close to Ethyl acetate and you want to try and distill Ethyl actetate only. Acetone has a boiling point of 56.C. Sorry if i caused confusion. I will see if I can find any literature about whether Butyl acetate can be substituted. If you can't find it as the MEK substitute, Ethyl acetate is on ebay as "insect collecting fluid" and also from standard chem suppliers on there. [Edited on 23-11-2014 by greenlight]

Yeah, only I was confused, not we I figured that out later...

However, distillation is done!

My nail polish remover contains: butyl acetate, ethanol, acetone, butyl stearate and ricinus communis oil (castor oil).

Here are all ingredients, sorted by boiling point:

Acetone: 56°C
Ethanol: 78°C
Butyl acetate: 126°C
Butyl stearate: 220°C
Castor oil: 313°C

First, I used water boiling bath to distill all of the acetone and ethanol. Then I cleaned condenser and put all of the acetone/ethanol mixture in the bottle and cleaned the beaker. I repeated the process, but without water bath - just directly on hotplate. I left it distilling for up to 196°C and it still boiled a little, but the boiling drastically slowed down at about 150 or 160°C. That way I've collected butyl acetate (I could tell by smell that it wasn't acetone or ethanol). At the end, I was left with castor oil and butyl stearate, which is just a fragrance, so it's probably mainly just castor oil, that was left and maybe a bit of butyl acetate.

On the picture below, there are products of distillation.

In the first bottle, there is acetone/ethanol mixture (about 40ml).
In the beaker, I don't know what it really is (10ml), but it was collected between 100°C and 124°C - probably there was still ethanol left, or something, is it water? But I don't know why it didn't evaporate before at 100°C? (I started collecting butyl acetate at 124°C although BP is 126°C).
In the second bottle there's a final product, butyl acetate (about 35ml).
And in the erlenmeyer flask, there's the castor oil, butyl stearate and a little amount of butyl acetate (15ml). I used 100ml of nail polish remover.


The next thing to do is getting some ammonium hydroxide or making it and then hopefully after mixing it with butyl acetate, the reaction will take place and make some acetamide But that's unfortunately maybe not gonna happen :-/

Thanks for helping



[Edited on 23-11-2014 by xfusion44]

PS: castor oil has a nice smell of peanut or walnut

[Edited on 23-11-2014 by xfusion44]

Thanks for support

I agree that it probably won't work, so today I'll go to see if I can find ethyl acetate nail polish remover anywhere.

Thanks again, when I find something I'll be back

Quote: Originally posted by greenlight

Well done. I have been looking around and I'm pretty sure the Butyl acetate is a no-go in the production of Acetamide. At least you have some experience distilling nail polish remover now for when you find an Acetone-free brand which contains Ethyl acetate.

Finally I've got the right thing

I'll distill it when I'll have some time. Do you thing that the ethanol will be a problem?

However, here it is, acetone free NPR, with ethyl acetate:

Put it in the distillation apparatus and collect the different fractions at different temperature ranges like you did the last bottle and take it slow and see what you get. The boiling points are as follows:

Ethyl acetate = 77.1.C
Denatured alcohol = 78.3.C
Water = 100.C

The Ethyl acetate and Ethanol are very close together again so a fraction column would be recommended but you do not have one. If you have a spare condenser you could attach it between the boiling flask and still head and pack it with broken glass to slow the vapors.
I think the Ethyl acetate may form and azeotrope with the Ethanol because of the very close boiling points and maybe even the water so they may come over together regardless.
If you get an azeotrope, they can be separated by extractive distillation with another solvent which doesn't look too difficult. I found this on a patent:
"A method for recovering ethyl acetate from a mixture of ethyl acetate and ethanol which comprises distilling a mixture of ethyl acetate and ethanol in the presence of an azeotrope forming agent, recovering the ethyl acetate and the azeotrope forming agent as overhead product and obtaining the ethanol as bottoms product, wherein said azeotrope forming agent consists of one material selected from the group consisting of methyl formate, 2,2-dimethyl butane, hexane, cyclopentane, 2,2,4-trimethylpentane, t-butyl methyl ether, petroleum ether, dimethoxymethane and 4-methyl-2-pentanone."

And heres a link to another patent discussing the separation of Ethyl acetate and Ethanol by distillation with Methanol:

http://www.google.com/patents/US2649407

Quote: Originally posted by DistractionGrating

OK, this may not be a chemistry question, per se, but it does involve the physical properties of a substance, and so, please indulge me, if you will. Some people assert that there are ways to somehow cut or grind holes in tempered glass without it shattering. Is this possible? If so, how?

Quote: Originally posted by greenlight

Put it in the distillation apparatus and collect the different fractions at different temperature ranges like you did the last bottle and take it slow and see what you get. The boiling points are as follows: Ethyl acetate = 77.1.C Denatured alcohol = 78.3.C Water = 100.C The Ethyl acetate and Ethanol are very close together again so a fraction column would be recommended but you do not have one. If you have a spare condenser you could attach it between the boiling flask and still head and pack it with broken glass to slow the vapors. I think the Ethyl acetate may form and azeotrope with the Ethanol because of the very close boiling points and maybe even the water so they may come over together regardless. If you get an azeotrope, they can be separated by extractive distillation with another solvent which doesn't look too difficult. I found this on a patent: "A method for recovering ethyl acetate from a mixture of ethyl acetate and ethanol which comprises distilling a mixture of ethyl acetate and ethanol in the presence of an azeotrope forming agent, recovering the ethyl acetate and the azeotrope forming agent as overhead product and obtaining the ethanol as bottoms product, wherein said azeotrope forming agent consists of one material selected from the group consisting of methyl formate, 2,2-dimethyl butane, hexane, cyclopentane, 2,2,4-trimethylpentane, t-butyl methyl ether, petroleum ether, dimethoxymethane and 4-methyl-2-pentanone." And heres a link to another patent discussing the separation of Ethyl acetate and Ethanol by distillation with Methanol: http://www.google.com/patents/US2649407

Thanks for that

Hopefully I'll have some time today for this distillation, otherwise I'll do it ASAP.

I'll be back

Thanks

@greenlight

I've bought 25% ammonia solution and ethyl acetate - I will still try to get EtOAc from NPR, but just in case

I have a problem: how do I know the density of dissolved gas in water (ammonia)? I calculated, that there is 342,466 liters of gas in one kilogram of 25 percent w/w ammonia and I would like to know the volume of one kilogram of 25 percent w/w ammonia solution, but I can't just take usual density of ammonia into account, since the volume of one kilo 25percent ammonia would be above 343 liters. Please help :-/

Thanks!

PS: I know from wiki, that the volume of 1kg of 25 ammonia is about 1,01l, but there must be a way to calculate that, right? For example: how do you know, that 342.5l of ammonia gas is just about 260ml when dissolved in water? Or is it actually ammonium hydroxide, and there is no actual gas dissolved?

[Edited on 29-11-2014 by xfusion44]

Quote: Originally posted by j_sum1

True. But in applications where ammonia solution is being used for its alkaline properties it makes sense to emphasise the "hydroxide" especially since the equilibrium dictates that it will be replaced as it is being used.

@greenlight

No, I was making acetamide with it, I bought 25 ammonia or NH4OH, whatever is correct to say... I wanted to calculate how much of each I mix...

However, I failed! First, I tried with my own EtOAc and 25 ammonia and 3h mixing, until all has reacted... After evaporation, there was nothig left. Again, with pure EtOAc and 5h mixing, after evaporation, there was nothing left I was expecting some crystals of acetamide :-/ Reaction mixture turned cloudy when it was on warm place, so I thought that some crystals are forming, but nothing...

Don't know, what else to do

Polesch on this forum didn't have problems, even with 9 percent ammonia, but I have with 25.

Also, I noticed, that during mixing, half of liquid was gone, but I don't know, how...

Thanks

[Edited on 1-12-2014 by xfusion44]

Yes, it did form two layers, which were then turned into one, after stirring for 5 hours.

Maybe it does take longer, but I'm afraid, that all of the solution will evaporate during stirring, because I've lost more than a half of it last time, during stirring and I still don't know why? I was stirring it on a cold place outside...

I'll check the link, when I'll have some time.

Thanks