Identify an unmarked bottle of acid

Being a hoarder, I have a large brown bottle of acid that came out of a school lab a good few years ago hidden in a dark place under my bench. It's most likely either Sulphuric or Hydrochloric since they generally didn't deal with anything more lethal on the school curriculum.

The problem is that there's no marking on the bottle, So I don't know which it might be.

Is there any easy way to test it. Maybe some members with a good chemical knowledge could advise please?

And then, when/if I do identify it, what would it be useful for in the workshop?

John

Having had the distinctly unpleasant experience of having being burnt and injured in a botched experiment in our school science lab in 1959 I would advocate extreme caution with said brown bottle.>>

In my late sixties I still have vivid memories of us school kids after the explosion, bloodied and boarding the ambulances in our shredded and smouldering uniforms. (Seriously, not joking).>>

What would I do if I had a brown bottle like yours? -------Vacate the workshop and call the emergency services. At the least neutralize the contents by adding to an annoying relative - although using this method to dissolve a marriage might be unwise.

Rik>>

Hi John, Mix it with lots & lots & lots & lots of H2O to make it safer, then water the Dandelions.

Terry.

Hi John. Firstly, though I really don't want to scaremonger, I should say that personally I would approach any unlabelled bottle from a science lab, even a school one, with great caution. I have spent many years in academic labs, and even in today's hyper-cautious H&S culture one finds bottles of quite scary stuff which have been sitting around in cupboards since more relaxed times.

Having said that, identifying your acid (if you're really sure that's what it is - you don't say what data you have) depends on whether it is concentrated or dilute. Concentrated is easy - dilute needs some chemistry.

So far as I know workshop uses of mineral acids are confined to pickling and in the case of dilute sulphuric, anodising. Others may know more - I know a lot more about chemistry than engineering! Personally I would get rid unless you have a specific need - these things are potentially hazardous and can play havoc with machinery if they get in the wrong place, which happens more easily than you might think. You can buy them in fairly cheaply if and when need arises.

Regards, Bob.

Edited By Robin Graham on 12/01/2014 00:16:45

I agree with Bob. Terry, even diluted, its still an environmental hazard. Yes, the old adage "The solution to pollution is dilution" may be correct but best to dilute and neutralize with some plain fine garden lime. Do this outside, in a hole in the ground preferable with a breeze behind you. Depending on the age of it, it could be very prudent to call the fire brigade to remove it. You wouldn't want the bottle shattering and getting a splash of, worst case, hydrofluoric acid on you. Its the acid that keeps on giving..right through your foot!

Take care

Andrew

Hi John,

if you think it is either Sulphuric or Hydrochloric acid and they are concentrated, the hydrochloric acid gives off nasty fumes when you open the bottle. So does concentrated nitric acid. If there has been any steel objects stored close to your acid bottle and it contains hydrochloric acid the steel should be brown with rust.

If diluted hydrochloric acid it will cause a white precipitation if mixed with a silver nitrate solution.

Neutralizing the acid with lime (or soda) as recommended by Andrew works well.

Andrew, if the bottle is made of glass I don't think it is hydrofluoric acid John has got.

Thor

Edited By Thor on 12/01/2014 06:22:10

Hi Thor

Agreed, if the source has been the high school chem lab, its most likely HCL, H2SO4 or Nitric. Maybe even phosphoric acid. A university lab may have HF on its shelves but its kept in glazed ceramic bottles I recall.

Also, I just recalled, if its concentrated sulphuric, it could be quite hazardous diluting with water as there could be localized boiling and it could splash everywhere!

Andrew

A bit of reading, in laymans terms, about acids and bases in the blog at Prospectors Paradise **LINK**

Hello John,

In the absence of any definitive test you are likely to be able to conduct, the safest course of action is disposal. Dilutuion with water is the first step BUT, please ADD ACID TO WATER. If this is concentrated sulphuric acid and water is added to it , the water will boil and you will have a steam bubble blowing acid everywhere.

Having diluted it, add a large box of washing soda until all reaction stops. You will then have a safe liquid to dispose of onto say a gravel driveway. I recommend gloves and a face mask until it is finally dealt with. Then wash everything down.

Brian

Hi John

As a first step I would ask your local chemist shops if they can take it. Boots took a bottle of conc Sulphuric from me a few years ago and did not charge. If not then try your local council if they know anywhere local to you to take it. I do not think your fire brigade will take it. I used lots of acids at work mostly HF back in the 80/90's and all of the HF was in plastic bottles.

Mike

Are you even sure it's acid?

Big brown bottles could contain all sorts of stuff. Clearing out my Father in Law's flat we found a big brown bottle that had once contained ether - for making CI engine fuel. It was empty but if it had been half full and the label had fallen off...

I have one in my workshop of universal indicator. Mostly alcohol and with toxicity warnings. The label is in good nick and it's in a safe place.

Neil

Hmm

A local antique dealer had a set of old chemists bottles in the window. The ones with glass stoppers and varnished hand written labels, very nice, and complete with pretty contents, in the front window on sale as ornaments!

One was marked corrosive sublimate the old chemical name for Mercury Chloride it was half full of the chemical a white crystalline mass. The antique dealer thought it was interesting. I can only wonder about the other bottles.

He was surprised when I told him how poisonous it was. I am not a chemist but had purchased a few grains from a chemical supplier to make a bluing solution for steel previously. The formulas, there are many, are in the Modern Gunsmith by James Vergil Howe if anyone is interested, you can find it on line. I guess you could not even buy it now due to regulation. even then I had to sign the poisons book and give a declaration.

On the unknown Bottle. Acid?. If it is any tools near it may rust badly if it fumes through the cap.

Regards
John

Don't mess with it - contact your local Council. Pack it very well when transporting it. Don't lift the bottle by its neck because they can crack around there.

One good habit when you are dealing with anything that you are not sure of, is to smell the cork or stopper - don't put your nose over the container. Waft the stopper in front of you and sniff the 'trail' that it leaves.

Hi John,

Concentrated sulfuric acid is almost twice as dense as water so carefully picking up the bottle may tell you what it is. If on opening the bottle it appears to fume then it is probably concentrated hydrochloric or nitric acid. To test between the different acids I would pour a little into a beaker and add a small amount of slaked lime, if this does not dissolve then it's probably sulfuric, if it dose dissolve then try a fresh sample on clean copper, if the copper is attacked giving off a brown gas or a clear gas then the acid is nitric (brown + concentrated, clear = dilute) (these gases are poisonous). If the acid dissolves the lime but dose not attack the copper it is probably hydrochloric as the three acids mentioned were the main ones stored at school.

Play safe, and good luck.

Peter.

Edited By Peter Tucker on 12/01/2014 19:38:02

John

Hydroflouric acid has been mentioned and, as has also been said, this is VERY unlikely if it is in a glass bottle. The acid is used to etch (ie dissolve) glass. I have a friend who is a glassblower - he is generally fearless in life but always EXTREMELY careful with hydroflouric acid. If you look at the Health and safety section HERE you will see why.  Note also the dangers associated with heating PTFE

If you don't know what the acid is seek professional help with its disposal.

Norman

(P.S. I'm not available!)

Edited By NJH on 12/01/2014 20:27:33

You have made me think twice about exploring my brown bottle!

I don't actually know if it is acid, now that the question has been put to me. There is no sign of rusting in the vicinity and I have not opened it in years. Having read the posts I may do so carefully and have a smell but after that ....well, old sayings about curiosity and cats or no-go areas for angels treading spring to mind.

It can be difficult for the terminally curious to leave things alone but Bob, your point about purchasing a small amount of a KNOWN substance if/when needed perfect sense. As I have no immediate use in mind and there were few suggestions of what could be done with it, I agree my workshop might be a safer place if I can neutralise it or otherwise dispose of it.

Thank you all for your good advice. I learned a lot from the replies.

John

Recently there was a good thread on derusting with hydrochloric acid. Most acids will do this.

If you work much with steel, you can save lots of dosh buying black bar instead of bright and pickling it to remove scale, with the bonus of being more stress relieved.

I once had an Edwardian book that was filled with lots of useful chemical recipes for home and small workshop use. One of the more interesting ones was a set of instructions to brew nitroglycerine, though it did tell you to be careful.

Between the wars, my dad bought gunpowder over the counter, buried a bomb in Dartmouth College's parade ground and blew it up as part of graduation celebrations. He and his chums were just told to reinstate it.

I can't help feeling that we've become a nation of wusses to be scared of something that is really quite easy to test in a safe manner using the brains that the good lord gave us.

Disposing it with the powers that be is a bit rude since it costs a great deal of money to do it officially which is a service we all pay for.

I would say, however, that if you keep it, do label it, even just "Unknown Acid", since you never know that the proverbial bus with your name on it isn't on its way.

Falco, I spent many years as a secondary school science teacher who wasn't afraid to take risks but I wouldn't touch it - literally! You only suspect that it's an acid and have no idea of the concentration. Unless the school from which you obtained it was very different from the ones I taught in there would be many acids and alkalis of various strengths and vintages around. On one of our periodic 'clear outs' we found an old bottle of Picric acid (gm for gm several times more powerful than TNT) that had completely crystallized and could have exploded simply by unscrewing the cap. Remember, also, that what was originally in your bottle may have decomposed to something even more nasty by now.

I wouldn't even try to move it until you've spoken to the hazardous waste bods at Environmental Elf. Ray.