[zeshkani]

iam working on a experiment, and since i read if you combine hydrochloric acid + nitric acid = aqua regia which can dissolve gold and platinum
where can some get these two acid's? also is there anything stronger then aqua regia, since it cant dissolve iridium??

[Alberto_Kravina]

Why do you need the aqua regia? It is a pretty nasty and dangerous thing... I think that you need some kind of permission to buy conc. nitric and hydrochloric acid
There are some other substances that are stronger, by the way...

[pantone159]

You probably need to find a chemical supplier to get nitric acid, it is not in any consumer products.
You can easily find HCl as 'Muriatic acid' in hardware stores, it is not quite as strong as 'concentrated' but it is close.

[limpet chicken]

There are some aquarium PH down products that contain nitric acid, usually I believe, it is phosphoric acid, but some contain HNO3.

[constant thinker]

I thought muriatic acid was around 25%. Nitric acid purchases of a certain about are monitored by the government. I tried buying from one company on line and they asked me about my qualifications, which are well non-existant. Concentrated nitric acid may be a little hard to get a hold of in large quantities.

See http://en.wikipedia.org/wiki/Aqua_regia for more information if you'd like. I haven't read it, but it probably has a few usefull things in it. You also probably don't want to store the stuff. My guess is that some of it will decompose into Cl₂ which is corrosive.

By the way Mark Kness, I was unable to find sulfuric acid at the hardware store.

[pantone159]

The 'Muriatic acid' I had at one point was labeled 31.45%.  ('Concentrated' is 37%.)  It probably varies a bit.

Too bad about not finding conc. H2SO4.  I could give you the name of a place in Austin TX that has it, but that probably doesn't help you.  I forget what the brand name was.

You don't want to store aqua regia, that is correct.  I think it tends to build up pressure, then the container explodes and splatters concentrated acids all over the place.  Not good.

[Borek]

then the container explodes

You may want to discuss it with mike

[constant thinker]

then the container explodes

You may want to discuss it with mike

Lol. Good comment Borek.

Mark Kness it probably does vary from brand to brand. I found some concentrated Sulfuric Acid online. 500ml, 11$, 90-98% concentrated from Fisher Scientific.

Nitric acid is hard to come by concentrated. It's also really expensive.

[zeshkani]

looks like i wont be able to this this experiment while nitric acid is close to impossible to get ?
but anyhow are there any stronger acids other then the combination of HCl + HNO3 ?

[mike]

You may want to discuss it with mike Wink

  LOL

zeshkani - what exactly is this experiment that requires aqua regia?

I used to use aqua regia to clean some of my sintred filters and sometimes some glass ware.

[ATMyller]

There are stronger acids than aqua regia. Some superacids like fluoroantimonic acid have over 10¹⁹ times higher pK_a value than sulphuric acid. But even those aren't enough for iridium. Iridium can be made into ionic form and then dissolved only with some molten salts like Na₂O₂ and NaCl.

[Alberto_Kravina]

You don't want to store aqua regia

IIRC aqua regia shuldn't be stored at all because it decomposes...

The muriatic acid that you buy at the store here in Italy is about 12-15%...definitely not enough concentrated to make aqua regia....

[jdurg]

Aqua Regia is never stored.  It is only made as needed just like nitration mixtures.  In a pinch, using a combination of concentrated HCl and some nitrate salts can work if the nitrate salts are added slowly to a very chilled HCl solution.