cleaning solution

[akcapr]

I have sme glass ware that scrubbning and soap wont clean off. Theyre stained by stuff such as metal salts and stuff. What chemical mixture/solution will clean them up? Perfereably ones that do the cleaning without scrubbing.

[xeluc]

Conc. HCl will get most salts off glassware...

[P-man]

Just any old strong acid should do the trick.

[akcapr]

Hmm i guess that would work but i dont want to waste plenty of good acid.

[xeluc]

It's not wasting if you get something done with it that nothing else could achieve. Besides. HCl is like 4-5 dollars a gallon at the hardware store. and all you'd need is like, a capful or two.

[akcapr]

Ya thats what i was thinking. What i meant is i only have a few ml left of all my strong acid. So i guess i will just go to the hardware store and get soem. Can someone remind me in what section it would be in?

[raivo]

You may try with vinegar or acetic acid. Sometimes it works. I usally do this with boiling battery acid.

[YT2095]

So i guess i will just go to the hardware store and get soem. Can someone remind me in what section it would be in?

 

Brick and Masonary section, it`s a cleaner.

[Borek]

IMHO battery acid (sulfuric) will be not as good as muriatic (hydrochloric), as there are much more insoluble sulfates than chlorides.

 

Best,

Borek

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[YT2095]

a method I used to use ages ago (before I could afford to throw test-tubes away), was to use sand, simple sand from a builders yard or the beach.

put 2 T spoons of that in the test tube, half fill the rest with water, pop the cork in the end and shake the sucker like hell!

 

Crude but effective

[jdurg]

When I worked in a research lab, we cleaned EVERY piece of glass equipment with a solution of nitric acid. Nitric acid will dissolve just about anything, and I don't know of a single metal nitrate that isn't soluble.

[YT2095]

and I don't know of a single metal nitrate that isn't soluble.

 

`Coz there isn`t one

 

(although there are some metals that won`t form Nitrate compounds)

[woelen]

My best experience is concentrated HCl, cheap and simple. It works well, because of its strong acid content, combined with the good complexing capabilities of chloride ion.

 

Sulphuric acid does not nearly work as well. Concentrated nitric acid also works great in many cases, but why use such a precious chem, while dirt cheap and easily available HCl also does the job.

 

If nothing of these works, then you a mix of HCl, HNO3 and some HClO4 certainly will work, but only as a last resource, it uses up very precious chems.

[budullewraagh]

see, i never understood why people used HF to clean things when nitric would work so much easier. HF is bloody toxic as all hell, while nitric is not nearly as dangerous

[sungmintd8]

Nitric fumes, I'm pretty sure are posionous.

[YT2095]

some HClO4 certainly will work.

 

are you Crazy!? that stuff`s Lethal:eek:

I still wouldn`t be happy using perchloric acid if it were in a steel reinforced concrete bunker and done by remote control!

[woelen]

are you Crazy!? that stuff`s Lethal:eek:

I still wouldn`t be happy using perchloric acid if it were in a steel reinforced concrete bunker and done by remote control!

YT, isn't that a little overreacted ? I have 60% HClO4 and I'm using it fairly comfortably. Nice stuff to play with, but unfortunately it is quite expensive. No, HClO4 is not that bad, in fact even less worse than HNO3 of the same concentration.

 

Have a look at this:

 

http://www.gfschemicals.com/technicallibrary/perchloricacid.pdf

 

This link takes away a lot of the myth around HClO4.

 

I own some 60% HClO4 and in fact it is favorite for me, because it is totally unreactive (other than being a strong acid). It does not form any complexes with metal ions and it does not act as an oxidizer, other than the simple H(+) ions do. This makes the acid very valuable for me, because I do a lot of experiments in coordination chemistry and then sometimes sulphuric acid and certainly hydrochloric acid are a real pain, because of complex formation. Nitric acid also is quite problematic, because of its oxidizing properties at higher concentrations. What remains is HCl04.

 

HClO4 only becomes really dangerous, in combination with other strong oxidizing acids and at very high concentrations (more than 80% or something like that).

[jdurg]

The big problem with perchloric acid that is not exaggerated is the reactions between HClO4 and many organic compounds. Perchloric acid accidents typically happen when the acid is used in a fume hood not designed for perchloric acid. While HClO4 is not volatile at room temperature, virtually all reactions involving a concentrated acid don't remain at room temperature. Remnant organics in these fume hoods may then get a chance to react with the perchloric acid and some unstable organic compounds could form.

 

That's the main thing behind the danger of perchloric acid. The toxicity, as woelen pointed out and that perchloric acid producer/seller's article pointed out, is not really there.

[woelen]

Just to prove that perchloric acid is not very reactive when below 72%, try the following for comparison (YT probably has the chems):

Add a pinch of calcium hypochlorite or 1 ml of hypochlorite bleach to some conc. HCl: You'll see formation of chlorine gas. Note the stench. This reaction is immediate. Do this outside and do this with no larger amounts, than mentioned above.

 

Add a pinch of KClO3 to conc. HCl: The liquid will turn yellow and you get a deep yellow gas. This is a mix of ClO2 and Cl2. Quite dangerous, but in the small amount used here, this reaction in fact is quite fun. It demonstrates that chlorate is less reactive than hypochlorite. ClO2 is not nearly as toxic as Cl2, but it is dangerous. It may spontaneously explode, but if this experiment is performed with a clean test tube and the gas is allowed to simply diffuse into the air, then you do not need to worry about explosion.

 

Finally, add a pinch of KClO4 to conc. HCl. Nothing happens. Bring the solution to a boil. The KClO4 dissolves and still nothing happens! Hardly any Cl2 gas, only the stench of HCl vapor. I even boiled 60% HClO4 with solid KI and even then only a tiny amount of the iodide is oxidized to I2, really remarkable.

 

So, from these three experiments you can see that perchlorate in aqueous solution is as energetic as a dead dog and even NaCl is more interesting in aqueous solution than KClO4. Only at very high concentration of acid (72+% of HClO4 or at highly elevated temperatures, red hot, the perchlorate ion shows its real nature).

 

What jdurg mentions about perchloric acid vapor, soaked into wood and other organics, yes that is a real risk. This, however, will not occur with 60% solutions. The vapor pressure of HClO4 is very low. It forms an azeotrope at 72% which boils at 190 C or something like that.