Little_Ghost_again
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Registered: 16-9-2014
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Why the acid cloud?
I am not even sure anyone is going to believe this but this is exactly the details and I will explain why.
Lately I have started to store my mineral conc acids in an unheated very very cold outbuilding, mostly because I am trying to sort my lab out and dont
have much storage in it at the moment as i took most of it out so I could put some tiles on the wall.
The building I used for storage was what I used for my old lab for nasty stuff and soap making. It has no heating at all and the only kind of bench
space left in there is my old version fume cupboard.
The room was around 2-3C and I am guessing so was the acid as I havnt moved or used the main container.
I also keep 30ltrs of RO water out there in 3 containers, again because I dont have storage room inside until I finish the lab, so the water was also
around 2-3C. I needed to acid was some yeast alginate balls and my stock solution was used up and I needed to make more.
I dont carefully measure this as its really not that critical, so as normal I poured 1.5ltr RO water into a 2ltr beaker I keep in the fume cupboard
(only work surface there now), then I added around 20-30ml of 36.6% Hydrochloric acid to the water, I just kind of pour it in at a slowish pace (2-3
seconds roughly).
Now I have done this loads and loads lately because of yeast experiments (it was for this I needed the acid), sometimes its been a bit warmer in room
but not much (5-6C).
Ok I am used to seeing the little white cloud as i open the acid bottle and pour the acid into a small beaker, I dont bother with the fan on the fume
cupboard because it rarely produces little more than a whif of fumes, then I pour that beaker into the water beaker simples...........
EXCEPT this time and for no apparent reason i can see the acid FUMED like mad the moment it hit the water! There was a huge cloud white vapor came
pouring out the cupboard!! I have never seen anything like it, a thick white cloud!!
Lucky enough its a home built hood and there is a panic button on the edge of the cupboard that puts all 6 fans on full blast instantly (I normally
use pwm speed control as they large DC fans).
So no harm done but it fumed for around 10 seconds or so!! Does anyone have ANY idea what might have happened? If my old bench had still been in the
building I would have used that and not the fume cupboard, pure luck I used the fume cupboard because I didnt have any other surface to use.
Ok so I will always use the hood from now on but I would like some idea why this happened in the first place, I do this alot and so far no problems
until now.
The only thing even slightly different to normal was the fact I used the RO water from the plastic water containers I top my aquariums up with,
normally for lab water I use a 20LTR glass thing with a glass tap on it, I only use this normally because I got it for £3 off ebay and it looks way
cool lol, it is designed for labs though as I got it from a closing lab on ebay along with other glass.
Is it possible that plastic water containers designed for camping etc could leach something that would do this?
It really shook me up as I was not expecting it.
Dont ask me, I only know enough to be dangerous
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HgDinis25
Hazard to Others
Posts: 439
Registered: 14-3-2014
Location: Portugal
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Mood: Who drank my mercury?
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You seem to be describing the reaction between Ammonia solution and Hydrochloric Acid. When you take the two solutions near each other you can already
see gas-phase reaction to produce white fumes of Ammonium Chloride.
When you add both solutions you get an ejection of white fumes immediatly, again Ammonium Chloride fumes.
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Jylliana
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Registered: 3-10-2014
Location: The Netherlands
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Mood: Bubbly ^-^
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I don't see any ammonia described anywhere ...
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Little_Ghost_again
National Hazard
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Mood: Baffled
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Thanks for this! As mentioned I have aquariums so I have test kits for them, one of these is for ammonia. I tested the water containers and the new
one I got a few weeks ago goes bright red on the test. So I know the water itself was not to blame because I use a RO unit thats got a monitor on, so
that leaves the actual container itself.
I got 2 new ones, one for fish use and one chemistry use, the fish one gets used alot but even that shows aq small amount of ammonia. I am guessing
whatever the plastic is its leaching it.
Dont ask me, I only know enough to be dangerous
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HgDinis25
Hazard to Others
Posts: 439
Registered: 14-3-2014
Location: Portugal
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Mood: Who drank my mercury?
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@Jylliana
Sometimes you need to think outside the box. He didn't know what was causing it so contamination that he is not aware of is always a good place to
start.
@Little_Ghost_again
Nice to hear you've discovered the source problem. May I ask what type of plastic is your container made of?
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Little_Ghost_again
National Hazard
Posts: 985
Registered: 16-9-2014
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Mood: Baffled
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Quote: Originally posted by HgDinis25  | @Jylliana
Sometimes you need to think outside the box. He didn't know what was causing it so contamination that he is not aware of is always a good place to
start.
@Little_Ghost_again
Nice to hear you've discovered the source problem. May I ask what type of plastic is your container made of? |
There is no indication of what the plastic is not even a recycle number!
It is meant for food use as its sold as a water carrier for camping, it was cheap off ebay, semi clear plastic similar to all other water carriers I
have except perhaps slightly more opaque.
I sold my marine tank thank god before I got theses containers, I shudder to think about using water from these in an aquarium.
My dad isnt sure its the plastic as such, he thinks its more likely they were second hand (they looked new) and used to store ammonia in. my test kit
only goes to 75ppm and they test off scale, January I get the Gas for the GC so will have a look with that.
What I still dont get is the amount and size of the cloud, I have been trying to think of a way to describe what happened the best I can do is think
of when you see vids of people putting dry ice into boiling water. The volume was kind of like that but the cloud was much much lighter in the sense
that it didnt hang around the bottom of the beaker or go down to the floor, it rose! and rose. and spread out at the same time.
Like I say I cant see any reason why under normal situations I wouldnt have just done this on the bench, that is the bit that worries me. It was pure
luck I was doing it in a room outside the house, even more luck that I only had room in the fume cupboard to stand a beaker.
I am definitely going to arrange the fans on the new fume hood the same way though  , at least I know my extraction method works and a panic button isnt a waste of time after all lol, the only thing I will change is the
lights. The lights are wired to go out if the button is pressed, my thinking was the panic button would likely be used for petrol fume type situations
etc so the switch was there to stop sparks and put on fans. I will use sealed lights and leave them on
Dont ask me, I only know enough to be dangerous
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chemrox
International Hazard
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Six fans for a homebake fume hood? I'm impressed. I want to mention that anything you can do to create a constant temperature environment for storage
will save you $ in the long run. Containers breathe. They inhale and exhale with changes in pressure. Also segregate reagents; acids with acids etc.
As far as what happens when you place CO2 in hot water I don't think the chemistry is interesting. However if you want to describe what happens
mathematically the root equations might be in some of the declassified Los Alamos papers on "base surge.." The pathways taken by individual molecules
can be written down.
"When you let the dumbasses vote you end up with populism followed by autocracy and getting back is a bitch." Plato (sort of)
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woelen
Super Administrator
Posts: 7977
Registered: 20-8-2005
Location: Netherlands
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Mood: interested
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I know the effect, described by Little_Ghost_again. It is impressive and it only occurs at low temperatures near the freezing point of water.
What happens with conc. HCl is that gaseous HCl is expelled from the liquid. This goes easier if the acid is warm. The gaseous HCl itself is
invisible. The gas, however, reacts with water vapor from the air (HCl + H2O [+ nH2O] --> H3O(+)(aq) + Cl(-)(aq)). The funny thing is that the
resulting liquid has a much lower vapor pressure than both HCl and H2O. So, in-air you get a reaction between two gaseous compounds, which forms a
liquid compound. You observe this as little droplets (fumes). When the temperature is near the freezing point of water, then these droplets hardly
evaporate again and then these fumes linger for quite some time. A lot of fumes can build up in such cases.
What adds to the effect is that the conc. acid warms up a little when it comes in contact with water. So, you get extra HCl and this leads to
formation of extra fumes. Just do a little experiment:
Take 2 ml of water.
Add 2 ml of conc. (36%) HCl and swirl.
You'll feel that the mix of liquid is somewhat warm. This increase in temperature adds to the effect you observed.
For the same reason, you get wet bottles around bottles of conc. HCl in winter time when the liquid, formed from gaseous HCl and water vapor does not
evaporate. On hot summer days you will not observe this.
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Little_Ghost_again
National Hazard
Posts: 985
Registered: 16-9-2014
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Mood: Baffled
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| Quote: Originally posted by woelen | I know the effect, described by Little_Ghost_again. It is impressive and it only occurs at low temperatures near the freezing point of water.
What happens with conc. HCl is that gaseous HCl is expelled from the liquid. This goes easier if the acid is warm. The gaseous HCl itself is
invisible. The gas, however, reacts with water vapor from the air (HCl + H2O [+ nH2O] --> H3O(+)(aq) + Cl(-)(aq)). The funny thing is that the
resulting liquid has a much lower vapor pressure than both HCl and H2O. So, in-air you get a reaction between two gaseous compounds, which forms a
liquid compound. You observe this as little droplets (fumes). When the temperature is near the freezing point of water, then these droplets hardly
evaporate again and then these fumes linger for quite some time. A lot of fumes can build up in such cases.
What adds to the effect is that the conc. acid warms up a little when it comes in contact with water. So, you get extra HCl and this leads to
formation of extra fumes. Just do a little experiment:
Take 2 ml of water.
Add 2 ml of conc. (36%) HCl and swirl.
You'll feel that the mix of liquid is somewhat warm. This increase in temperature adds to the effect you observed.
For the same reason, you get wet bottles around bottles of conc. HCl in winter time when the liquid, formed from gaseous HCl and water vapor does not
evaporate. On hot summer days you will not observe this.
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This also makes sense as the water and acid are in a outside unheated room, I got the acids as a special deal and in much larger amounts than I would
normally buy (5ltrs each). The acid was in a cupboard so probably around 1-2C higher than the 10 and 20 ltr water containers standing on the concrete
floor.
it was in my old lab thats being converted so I have a temperature data logger in it and humidity sensor (sensiron sht71), over the previous days the
night temperature dropped just below 0C but average temp has been around 1-2C, the water itself I have measured at 1C and the acid is 3C (at the
moment)..
I tried adding some the acid to straight tap water (4C water) 2C acid, it does indeed fume a large amount!!
I also tried the colder water that has small amounts ammonia in it................I wont do this again! Yet again HUGE clouds from around 20ml acid
and 300ml water.
I have 6 fans because I arrange it so they blast air through a tube to the outside, there is another tube that drops from this into the fume cupboard
and 'sucks ' the air out the fume cupboard as the air rushes over it to the outside, I do this so there is no fumes at all get near the fans, the
downside is I need more fans etc to evacuate the fume cupboard.
I just dont like the idea of air from a fume cupboard coming into contact with any part of a fan unit, I have 3 medium sized fans for the new cupboard
they are the sort used for kids bouncy castles and work like the squirrel cage ones, they have huge air flow but are noisy and use alot of electric.
These are going to be on a variac so they dont drive me mad when its not needed, but again I will add a couple of panic buttons around the lab that
will switch them on full, I have also made a thick RTV seal and adapted my hood screen, its now full lengh sash type the side into the hood is double
glazed glass window pane (from scrap place) but on the other side to this I have added a sheet of tough acrylic.
This might seem utter overkill but is it? I am 14 and learning, already I have had a couple of fires and one serious sodium hydroxide burn, I have had
a minor explosion while not playing with pyro stuff! I figure I WILL make mistakes and things will happen that I dont expect to............I am now
going to tile the insde of the fume cupboard and put a small sink in it, the from panel can be sealed quickly and easily if needed, I have a nitrogen
cylinder on order for the GC so I might even plumb this in so I can fill the fume hood with nitrogen.
Until I know what I am doing and have an idea what to expect if something goes wrong I want to be sure I can isolate myself and whatever it is until I
can get it under control, I dont like the run away option as this seems like a good way for shit to get out of hand.
I keep reading some acids should be kept from each other, can someone finally clear this up for me please, do I keep Nitric,sulphuric,hydrochloric
together or not?
My oxidizers are kept in a separate cupboard from anything else (metal) all other chemicals are at the other end of the room, my large amounts of
Hydroxides are used for soap making mostly and are in another building well away from anything else, I do keep around 500g of each in the lab in
plastic bags inside kilner jars.
I dont have iodine yet but need it and I dont have bromine but will be getting some, because of this my fume cupboard is full bench lengh and has a
small section on the left that isolated from the main cupboard, it has a acrylic door inside the hood itself and this is where the iodine and bromine
will live with a small fan constantly on low.
Most of you will probably be ROFLTAO at all this, but I am enjoying building it and stated before with my track record It dosnt seem overkill to me
Thank WOELEN for verifying the acid thing, unless you see it yourself its hard to describe and if you dont know how it happened its scary as hell to
witness it!
Dont ask me, I only know enough to be dangerous
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woelen
Super Administrator
Posts: 7977
Registered: 20-8-2005
Location: Netherlands
Member Is Offline
Mood: interested
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Little_Ghost_again, you are doing very well. Good to see how you approach the hobby of chemistry and you'd better be prepared for the unexpected than
being caught by the unexpected.
What is most important for you is that you avoid frequent low level exposure to toxic chemicals. These low level exposures are more risky than fumes
of HCl or nasty encounters with small amounts of H2SO4. The reason for that is that they go unnoticed and slowly damage your health. Especially if you
are young and your body is not yet fully developed, it is important to be very careful with long term low level exposure. Such exposure may lead to
damage of your nervous system, may lead to decreased fertility, may lead to decreased intelligence, may increase the risk of cancer at a later moment
in your life. So, using a good fume hood is a very good idea.
Inorganic acids can be stored together (HCl, H2SO4, HNO3, HClO4). Organic acids like CH3COOH, HCOOH should be stored away from HNO3 and HClO4, but can
be stored together with HCl and H2SO4. Ammonia and strong bases (NaOH, KOH, Ca(OH)2, CaO, Ba(OH)2, etc.) should be stored away from concentrated acid,
beit organic or inorganic.
A very nice and impressive experiment, which is not bad for your health is pouring 25 ml or so of household ammonia on a plastic or glass plate (do
this outside). Pour 2 ml of conc. HCl on it (in the centre of the puddle of liquid) and watch the smoke. This is REALLY impressive and at the same
time it is 100% safe. The smoke is non-toxic (it is NH4Cl) and if you inhale some of it, you will hardly notice that you inhale it. It gives a certain
taste in your mouth, which is known as 'salmiac' (in the Netherlands, this is actually eaten: mixed with some sugar and a small amount of liquorice,
it is quite a popular kind of powdered sweet). Assure that you use excess ammonia, otherwise the smoke becomes very acrid due to the excess HCl and
then inhaling some of it is a nasty experience.
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Little_Ghost_again
National Hazard
Posts: 985
Registered: 16-9-2014
Member Is Offline
Mood: Baffled
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| Quote: Originally posted by woelen | Little_Ghost_again, you are doing very well. Good to see how you approach the hobby of chemistry and you'd better be prepared for the unexpected than
being caught by the unexpected.
What is most important for you is that you avoid frequent low level exposure to toxic chemicals. These low level exposures are more risky than fumes
of HCl or nasty encounters with small amounts of H2SO4. The reason for that is that they go unnoticed and slowly damage your health. Especially if you
are young and your body is not yet fully developed, it is important to be very careful with long term low level exposure. Such exposure may lead to
damage of your nervous system, may lead to decreased fertility, may lead to decreased intelligence, may increase the risk of cancer at a later moment
in your life. So, using a good fume hood is a very good idea.
Inorganic acids can be stored together (HCl, H2SO4, HNO3, HClO4). Organic acids like CH3COOH, HCOOH should be stored away from HNO3 and HClO4, but can
be stored together with HCl and H2SO4. Ammonia and strong bases (NaOH, KOH, Ca(OH)2, CaO, Ba(OH)2, etc.) should be stored away from concentrated acid,
beit organic or inorganic.
A very nice and impressive experiment, which is not bad for your health is pouring 25 ml or so of household ammonia on a plastic or glass plate (do
this outside). Pour 2 ml of conc. HCl on it (in the centre of the puddle of liquid) and watch the smoke. This is REALLY impressive and at the same
time it is 100% safe. The smoke is non-toxic (it is NH4Cl) and if you inhale some of it, you will hardly notice that you inhale it. It gives a certain
taste in your mouth, which is known as 'salmiac' (in the Netherlands, this is actually eaten: mixed with some sugar and a small amount of liquorice,
it is quite a popular kind of powdered sweet). Assure that you use excess ammonia, otherwise the smoke becomes very acrid due to the excess HCl and
then inhaling some of it is a nasty experience. |
I know the sweet! they do a version in the uk but its not as good! How do I know? My mum has a friend who is rather famous and lives over there, she
plays the sax  , we have been to Genk loads of times! I also like the mayonnaise on
everything including chips!!
I love Belgium but unlikely we are going this year (or next).
So the huge white cloud wasnt as bad as I thought! Good to know but man I nearly shit myself on the spot!!
I am really enjoying the making of my fume cupboard but its taking ages to complete! Not sure where the sink will be plumbed into as we have a septic
tank, I need to think about this.
Thanks for the acid info, I did search but there is so much conflicting advice on the net! I dont like APCPURE as a company but I have to credit them
with there acid bottles, they use much much better seals and caps! The HCL I have from them in 5 ltrs dosnt leak at all, the other cheaper bottle from
elsewhere looks like the same cap but isnt, that one does fume a bit. The Nitric is 50% and a nightmare!!
The bottle is now in bag after bag with some mag carbonate in and it still gets out even though its kept below 3C. I didnt go for the 69% stuff
because I figured if I ever need that I can use the 50% and just boil it down to concentrate it, but I cant see a need at the moment for any over 50%.
The H2SO4 is a yellowy colour, it claims to be 96.6%, like the Nitric I only have 1ltr of it.
It took a couple of near misses for me to realize that chemistry can go really wrong very very quickly, so now I try and at least make sure I am
protected.
I am reading the K thread..............Trying to decide if I can do that safely enough, I dont have all the materials yet but its tempting, then
again what would I use K for? I dont have much use for it at the moment as most of my chemistry is based around soap and biology stuff like
fermentation etc.
I like making test reagents for plant extracts etc and now I have a contact in Ireland for cheap Aldrich stuff
Dont ask me, I only know enough to be dangerous
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