Sciencemadness Discussion Board - concentrating household ammonia?

concentrating household ammonia?

harmlessexperiment - 27-2-2010 at 05:48

Hi, I was wondering if it would be possible to concentrate household ammonia (5-10%) to say 15M ammonia water?

I was thinking you could gas it with NH3, but how would you know when to stop?

[Edited on 27-2-2010 by harmlessexperiment]

hissingnoise - 27-2-2010 at 06:41

If you have a clear solution you can gas it.
An inverted funnel in a stirred solution will work best.
At saturation, NH3 will blow (cough!) out of the funnel and the supply can be stopped at that point.

woelen - 27-2-2010 at 07:29

You can concentrate dilute NH3 by adding a lot of NaOH to such a dilute solution and then heating it. NH3 gas will get out of the solution. You can lead that gas through another amount of dilute NH3 making stronger NH3.

harmlessexperiment - 27-2-2010 at 08:36

>>You can concentrate dilute NH3 by adding a lot of NaOH to such a dilute solution and then heating it. NH3 gas will get out of the solution. You can lead that gas through another amount of dilute NH3 making stronger NH3.

woloen: that sounds do-able, but determining the concentration of it would be difficult would'nt it?

See when NH4OH gets above a certain point it becomes unstable warm conditions. 15M is what I'm after. Or maybe slightly less. I mean yield is one thing, but having glass imbedded in your face is quite another.

harmlessexperiment - 27-2-2010 at 09:08

Quote: Originally posted by entropy51

Quote: Originally posted by harmlessexperiment

See when NH4OH gets above a certain point it becomes unstable warm conditions. 15M is what I'm after. Or maybe slightly less. I mean yield is one thing, but having glass imbedded in your face is quite another.

Dissolving NH3 in weaker NH3 solution will not explode, if that's what you think. It is exothermic so it needs to be cooled.

The concentration can be determined by measuring the density of the NH3 solution or guess what? Titration.

Hey Entropy, sorry for my poor choice of words. What I meant was that NH4OH solution in an enclosed containter can build up a lot of pressure, even in warm conditions.

About density, wouldn't that require a volumetric flask?

woelen - 27-2-2010 at 12:03

If you really want concentrated NH3, then start off from other things than dilute NH3. Mix a salt like NH4Cl, NH4NO3 or (NH4)2SO4 with solid NaOH and add a few drops of water to get the reaction starting. Pure NH3-gas is evolved and you can dissolve that in water until no more will dissolve. You can also use the NH3-gas directly.

Instability is not an issue with NH3, this compound is very stable.

ScienceSquirrel - 27-2-2010 at 12:28

The 10% clear solution is widely available where I live and I find it quite cheap and convenient to use.
It works out as about 5.8 molar which is quite a strong solution.
Certainly enough for most reactions and I have l have always had satisfactory results by adjusting the volumes or concentrating the solutions a little after the addition.
The 0.880 ammonia is available from specialist cleaning firms etc.

pantone159 - 27-2-2010 at 18:42

I am kind of confused about the labeling on the 10% solution. My ACE brand "Janitor strength ammonia" says '10% ammonium hydroxide' which I interpret as 100g of "NH4OH" (FW 35), which comes out to 2,85 mol/kg. But if I count 10% NH3, that comes to 5.88 mol/kg.

[sheepish]Sadly I have not settled the question by doing a titration.[/slacker]

Magpie - 27-2-2010 at 18:56

Quote: Originally posted by pantone159

I am kind of confused about the labeling on the 10% solution. My ACE brand "Janitor strength ammonia" says '10% ammonium hydroxide' which I interpret as 100g of "NH4OH" (FW 35), which comes out to 2,85 mol/kg. But if I count 10% NH3, that comes to 5.88 mol/kg.

[sheepish]Sadly I have not settled the question by doing a titration.[/slacker]

Pantone, I titrated my Ace janitorial as 5.1N and concluded that the "10%" is NH3, not NH4OH. Apparently this is a mislabeling by Ace. See:

http://www.sciencemadness.org/talk/viewthread.php?tid=4597#p...

Why are we so zealous about assisting this apparent drug cook, anyway?

psychokinetic - 27-2-2010 at 23:47

Quote: Originally posted by Magpie

Why are we so zealous about assisting this apparent drug cook, anyway?

'Cause this is the only thread they've made without making any dick moves thus far?

woelen - 28-2-2010 at 04:23

Quote: Originally posted by Magpie

Why are we so zealous about assisting this apparent drug cook, anyway?

The subject of making ammonia or concentrating ammonia is a subject which is quite interesting on its own. Ammonia has many interesting non-drugs applications in (home-)chemistry.

I would say that if a bottle tells 10% ammonia, then it is 10% NH3 and not 10% NH4OH. The "entity" NH4OH is a misnomer, it hardly exists and ammonia contains only a tiny fraction of NH4(+) and OH(-) ions.

psychokinetic - 28-2-2010 at 11:45

Quote: Originally posted by woelen

The subject of making ammonia or concentrating ammonia is a subject which is quite interesting on its own. Ammonia has many interesting non-drugs applications in (home-)chemistry.

I'd never trust myself to use a product I made for consumption/food related purposes (well, yet), but would there be much of a danger in concentrating NH3 for fertiliser use from household product?

ScienceSquirrel - 2-3-2010 at 16:01

Any technical chemical or reagent can be way off.
Really 10% ammonia could be as low as 5M or as high as 6M depending on how it has been made or how long it has sat on the shelf.
Most preparations use technical reagents and there are large excesses used.

harmlessexperiment - 6-3-2010 at 05:17

So let's talk about it.. HYow would you gas an NH3OH solution and then titrate it to determine the NH3 content? What equipment would one require? A dropping funnel? How long would it take.?

Guys honestly, I'm not a criminal. Atleast I'm not after making a profit etc. I just have a narrow set of interests. I'm not that good at chemistry but if you'd help me then maybe one day I could be? hear me?

User - 6-3-2010 at 06:18

http://en.wikipedia.org/wiki/Titration
Dude first hit on google...

harmlessexperiment - 7-3-2010 at 04:58

Quote: Originally posted by User

http://en.wikipedia.org/wiki/Titration
Dude first hit on google...

Thanks, Ill stop asking for spoon-feeding. Ill find the info. thanks again...

Oh one more thing. if someone could point me in the direction for a good beginners chemistry tutorial or pdf, then that'd be great.

Of course, for a titration tutorial I guess google would be adequate.

psychokinetic - 8-3-2010 at 11:44

What are you two thinking for? Stop it.
-------------------------------------------------

You're quite right, harmlessexperiment. A lot of people are weary of the internet because of its editability, but if you find the same information 5 times, it's *probably* correct. Just make sure you check out a web page's credibility before believing it and ending up blowing yourself up

Don't fear the google

Also, I'm pretty sure there are tutorial documents posted throughout this site. Tried searching?

dann2 - 10-3-2010 at 06:16

Hello,

In a last ditched desperate attempt at warding off the (evil and unbelievebly ugly) Pear of Salamanca I will give thee this link.

http://pubs.acs.org/doi/abs/10.1021/ed018p29

Dann2

not_important - 10-3-2010 at 09:11

If one lived in very southern climes, one could simply place a closed bucket of dilute aqueous ammonia outside near the end of summer, and in the depths of winter filter off a solution of about 30% . This seems about as practical as obtaining a tank of pure NH3 these days in many countries.

Else you could place dilute aqueous ammonia and sufficient salt to saturate that much water into a large flask, attach stopper with exit tube leading to an anti-suckback device (as posted early on) and slowly heat the flask of NH3 (aq) to near 100 C. The added salt helps drive off more of the NH3, and can be recover by simply allowing the remaining solution to evaporate. If you don't do that, the remaining rather dilute ammonia can be poured onto your compost pile.

NH3-H2O-1bar.gif - 7kB

bquirky - 11-3-2010 at 08:42

Perhaps the dude is making a fridge.. theres nothing wrong with ammonia

agorot - 11-3-2010 at 14:49

Know what I've always wondered? I know this is not really a biology forum, but I wonder if there is some nitrogen-fixing bacteria that can produce ammonia that the home chemist could isolate. How cool would that be?

Ammonia is quite toxic...maybe the bacteria would kill themselves off if you didn't keep removing the ammonia from the system.

Alternatively you could harvest ammonium nitrate how it was made the old-fashioned way and then use a strong base. I'd love to do this actually, but I'm not sure I'm willing yet to put up with the stink.

not_important - 11-3-2010 at 17:17

Nitrogen fixing bacteria do produce ammonia, but it is quickly cycled into producing amino acids. Concentrations of ammonia or ammonium ion above a half millimole or so tend to inhibit nitrogen fixation or even cell growth.

The "old fashion way" produced potassium nitrate or calcium nitrate. Bacterial metabolism of proteins releases ammonia from the amino group of amino acids, other bacteria oxidise the NH3 to nitrite and then nitrate. The nitrate is recovered as KNO3 if just organic material is used, if lime(stone) is added then calcium nitrate may be harvested instead. The subject has been discussed at some length in other threads.

Another old method was the treatment of urine with quicklime or slaked lime and them blowing steam through the mix to drive off ammonia. Destructive distillation of coal is yet another source, 2 or 3 kilos of NH3 per tonne of soft coal.

entropy51 - 11-3-2010 at 18:28

Quote: Originally posted by agorot

I wonder if there is some nitrogen-fixing bacteria that can produce ammonia that the home chemist could isolate. How cool would that be?

Not exactly nitrogen fixing, but some common bacteria such as Proteus vulgaris produce urease, which converts urea to ammonia.Unlikely to be a practical source of NH3.

But some plant seeds contain a lot of urease, for example jack bean and watermelon seeds. A mixture of urine and powdered watermelon seeds (!) kept at about 37 C, would likely produce enough NH3 to remove by aeration and trap in acid to make an ammonium salt. But really, (NH4)2SO4 fertilizer is so available and cheap, why bother?

agorot - 11-3-2010 at 19:21

I guess I should just pony up and go to the garden store then. I wish I knew what to get. The problem is that I'm no nice old grandma with a cane. It's not that I look like a druggie or wear a hoodie around with the hood up all the time, but I am a young, strong white male that probably looks like the stereotypical bomb-maker.

I'm also concerned that I wouldn't get something very pure, but if it's mostly ammonium sulfate then I could just add a base and probably wouldn't have problems.

Any way to easily identify an ammonium sulfate fertilizer? Or does it say it on the bag. I'm a little scared to browse the fertilizer section so I'm unfamiliar with the products, but maybe I'm just being unreasonable.

psychokinetic - 11-3-2010 at 22:38

I know that feeling, Harmless. You feel like a cook whether you are one or not.

I was just friendly and to the point. Said what I needed and got necessary help.
Even better if you do a bit more looking around and find out what you need. And yes, it should say on the bag.

not_important - 11-3-2010 at 23:52

Indeed, plain old ammonium sulfate is often sold as a fertiliser, no need to examine labels in detail. Urea is another, although I think it is becoming less common.

Purity isn't too much of an issue if you are using it to make NH3, as the gas phase part of the process does a decent job of cleaning things up. If you want it as a source of ammonium ions then solution, filtration, and crystallisation is needed. Ammonium sulfate's solubility curve isn't great, reuse the mother liquor several times to get better overall yields.

entropy51 - 12-3-2010 at 05:04

Quote: Originally posted by agorot

I'm also concerned that I wouldn't get something very pure, but if it's mostly ammonium sulfate then I could just add a base and probably wouldn't have problems.

Any way to easily identify an ammonium sulfate fertilizer? Or does it say it on the bag. I'm a little scared to browse the fertilizer section so I'm unfamiliar with the products, but maybe I'm just being unreasonable.

The stuff I buy says "Ammonium Sulfate" and is definitely not pure. It has small rocks in it, but if you heat it with base it makes NH3 just fine. I recrystallize it after filtering the dirt out, but it's not necessary at all.

You won't be arrested for buying the fertilizer your mom sent you to buy for her roses, will you?

watson.fawkes - 12-3-2010 at 07:11

Quote: Originally posted by agorot

Any way to easily identify an ammonium sulfate fertilizer? Or does it say it on the bag.

If it's not labeled explicitly (and as others have pointed out, it often is), you can often infer the chemical from the NPK designation. The trick is that there are a relatively small number of common, commercial fertilizer chemicals, and if the bag is not blended, the NPK designation is usually de facto unique. Here's a table with a few common ones. That one's not that extensive. I thought I had a better one bookmarked, but I can't find it. Expect some deviation from the "ideal purity" NPK number because you're dealing with fairly crude product in most cases.

agorot - 12-3-2010 at 14:59

@watson.fawkes

According to your link http://www.fertilizer.org/ifa/Home-Page/STATISTICS/Conversio...

the ammonium sulfate is only 21% of fertilizers....that's got to be wrong or this is talking about just one specific product, right?

dann2 - 12-3-2010 at 15:02

Ammonium Sulphate contains 21% Nitrogen and 24% Sulphur. Look up its formula and do a molar calculation.

agorot - 12-3-2010 at 15:04

Oh

. Misread the table then, I thought it was talking about the amount of ammonium sulfate in a bag. That makes sense.

MagicJigPipe - 13-3-2010 at 12:30

Quote: Originally posted by entropy51

You won't be arrested for buying the fertilizer your mom sent you to buy for her roses, will you?

Why would you even have to make up that story if persecution doesn't exist? Just walk in (wearing a tanktop and cutoff shorts) and say, "HEY! Anybody up in this b**ch know where I can get dat 'monium sulfurate so I can gas out some annie?" (don't forget to spit right afterwards)

Then they will say, "Sure you nice young man, would you also like a few boxes of cold medicine and a few truckloads of ammonium nitrate on us? Have a good day and enjoy!"

On a lighter note, I agree that adding cheap ammonium salt (chloride, sulfate etc...) to cheap base (Ca(OH)2, NaOH etc...) and heating is by far the best way to produce concentrated or liquid ammonia (if you have solid CO2). It is so soluble in water that the smell shouldn't be a huge problem (as long as you pay attention). I have tried this on a small scale once and the smell was virtually non-existent at first.

Good luck.

[Edited on 3-13-2010 by MagicJigPipe]