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Is there a real life chemical or compound that exhibits the characteristics of stereotypical movie acid?

From what I know of most acid, it is usually clear or just a little cloudy, but I'm looking for a substance suitable for a TV supervillain.

It must:

  1. Be a gross green color
  2. Bubble and or smoke menacingly
  3. Melt stuff

(Bonus points) 4. Glow

I don't want to handwave in some substance made by "science©", so I was wondering if anything either naturally occurring, or made by modern technology in our world works like this.

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    $\begingroup$ I wonder whether you'd allow a mixture of multiple materials, for example a tub of warm water to which we add: nitric acid, Cyamlume(R), a hunk of dry ice in the bottom, and an appropriate blend of food dyes. Nitric acid gives us the "melt stuff", Cyalume gives us "glow" and a bit of color, dry ice provides the "bubble and or smoke menacingly" and the dyes finish off the "gross green color." $\endgroup$ – cobaltduck May 30 '17 at 14:44
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    $\begingroup$ This is for a chemistry stack exchange. Maybe if you would drop point 4 - I've never seen that in fiction, glowing acid. I can think of a couple of answers, so please specify what you mean. 1: "gross" - do you have a specific shade of green in mind? This one is easy. 2: Well, if you boil it or if a chemical reaction is taking place - why else would it boil? Are you ok with it boiling because it was heated? 3: I don't know, if it's boiling, it could melt butter (which is a stuff), do you mean oxidize? Some acids do that. Maybe you mean a strong acid? 4: Chemiluminescence? $\endgroup$ – Raditz_35 May 30 '17 at 14:44
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    $\begingroup$ The best color for the "stereotypical" acid is probably chartreuse. $\endgroup$ – Michael May 30 '17 at 15:30
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    $\begingroup$ You could grow bateria to eat metals and glow green, although that is not a chemical per se. $\endgroup$ – Theraot May 30 '17 at 16:39
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    $\begingroup$ @cobaltduck That's be pretty funny, actually. "What's in there?" "Oh, that? Nitric acid! With a few ingredients mixed in to make it more menacing. Must keep up appearances, being an evil genius and all." $\endgroup$ – jpmc26 Jun 1 '17 at 4:44

10 Answers 10

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Dissolving folks quickly is hard work

Most acids aren't going to eat through you (or your average door) quickly -- while they denature proteins and dissolve metals, they don't have the oxidizing power to dissolve someone movie-style, and won't eat a doorknob faster than a drill bit. Even strong oxidizing acids can be sluggish by themselves under normal conditions.

There are some oxidizing reagents, however, that are capable of reacting that vigorously, and aren't completely out of reach of a supervillain. Mostly, they're used to deal with nasty cleaning/etching jobs IRL, far beyond the reach of anything you can get at the hardware store. Note that green and gooey aren't going to show up here -- gooey doesn't help you much when trying to get a vigorous reaction going, and very few things can produce a green color without getting eaten up by the stuff doing the dissolving. Bubbly, however, certainly will.

Piranha

The term "piranha solution", or just "piranha" for short, has a very specific meaning to chemists -- it's a reagent produced by mixing laboratory sulfuric acid with 30% hydrogen peroxide. The partial in situ sulfuric acid peroxidation that happens combines with the ability of sulfuric acid itself to abstract water away from molecules and the ability of hydrogen peroxide to attack carbon-carbon structures by producing carbonyls, yielding rapid dissolution of whatever organic matter gets thrown its way. It is much less effective against metals though -- only about as effective as sulfuric acid by itself.

Aqua regia

The other famed dissolving acid of history is aqua regia, a mixture of concentrated nitric and hydrochloric acids. While less effective against organic matter (nitric acid will oxidize it, albeit with a bit of sluggishness due to stuff getting nitro groups tacked on first), it is wickedly effective against many metals, even normally corrosion-resistant ones, due to the ability to form stable chloride complexes that drive the oxidation of the metal far to the right. It's also the most colorful of the reagents mentioned here due to the nitrogen dioxide, nitrosyl chloride, and chlorine that forms when it decomposes.

Perchloric acid

Perchloric acid is special, even as far as acids go -- it can attack and dissolve most metals all by its lonesome and is far more acidic than any other commonly produced industrial acid (its acidity puts it in the "superacid" category -- no other large-industrial-scale acid can claim that). Its technical grade is relatively sedate, but when concentrated well beyond that and heated, it is one of the most violent single-component oxidizing acids known, reacting violently or even explosively with organic matter. Atop that, many perchlorate salts are powerful oxidizers and even explosives -- ammonium perchlorate is used industrially in pyrotechnics and solid propellants, and friskier perchlorates such as heavy metal salts and alkyl compounds are well known to blow up at the first cross look they receive.

Chlorine Trifluoride

The one thing in our rogue's gallery that isn't acidic (I left elemental fluorine off as it's a cryogenic liquefied gas for most transport) is actually perhaps the most brutal of them all: chlorine trifluoride. This is one of the few reagents that will completely consume someone, pretty much irrespective of what they're wearing, in a matter of seconds to minutes. It will also do things like burn its way viciously through things that have already had as many oxygens stuffed onto them as they will ever take, such as concrete, as is fitting for a strong fluorinating agent. It is a volatile liquid stored under its own vapor pressure though, but does come the closest to meeting your color criteria.

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    $\begingroup$ Chlorine Trifloride really is what you're after. From Wikipedia: $\endgroup$ – AShireman May 31 '17 at 4:38
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    $\begingroup$ Take 2: Wikipedia it has a greenish-yellow color as a liquid and is extremely reactive. "It is also hypergolic with such things as cloth, wood, and test engineers, not to mention asbestos, sand, and water — with which it reacts explosively." Also, "a spill of 900 kg of chlorine trifluoride burned through 30 cm of concrete and 90 cm of gravel beneath". $\endgroup$ – AShireman May 31 '17 at 4:54
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    $\begingroup$ Sand Won’t Save You This Time - required reading regarding Chlorine Trifluoride. $\endgroup$ – user1975 May 31 '17 at 14:46
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    $\begingroup$ Chlorine triflouride. State of the art in nasty chemicals. $\endgroup$ – rackandboneman May 31 '17 at 15:59
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    $\begingroup$ @Snowman saw this question and instantly thought of his articles. You beat me to it! $\endgroup$ – Baldrickk Jun 1 '17 at 13:25
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Liquid Fluorine

  1. Vomit yellow in color
  2. Cryogenic liquid means it's boiling and smoking at room temperature.
  3. Melts/dissolves/burns almost everything
  4. "Glows" due to the burning of everything.

Only an actual psychopath would use.

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    $\begingroup$ 'Only an actual psychopath would use' - Obligatory XKCD $\endgroup$ – Joe Bloggs May 30 '17 at 15:33
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    $\begingroup$ Only a suicidal psychopath would use. $\endgroup$ – jamesqf May 30 '17 at 16:54
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    $\begingroup$ Isn't it also extremely, mindbogglingly poisonous, even if you breathe in just a microscopic amount of its fumes (which it produces a lot of)? I wouldn't even want to be in the same postal code where someone opens a container full of this stuff, much less in the same building. $\endgroup$ – vsz May 30 '17 at 19:01
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    $\begingroup$ It might be helpful to say what the precariously positioned vat labeled "ACME" would be made of. It sounds like most materials don't work $\endgroup$ – acbabis May 30 '17 at 19:33
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    $\begingroup$ The guy that first isolated it in (in 1886) received the Nobel Prize in Chemistry with this badass citation: "[I]n recognition of the great services rendered by [Henri Moissan] in his investigation and isolation of the element fluorine ... The whole world has admired the great experimental skill with which you have studied that savage beast among the elements." $\endgroup$ – tobek May 31 '17 at 4:16
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On Mythbusters Episode 206 ("Breaking Bad Special") the Mythbusters team experimented with various acids and tested their ability to dissolve meat.

They achieved the best results with a mixture of 70% Sulfuric Acid and 30% of another chemical which they only referred to as "Special Sauce" during the episode to prevent people from recreating their experiments.

Adam Savage revealed in a much later interview that it was Sulfuric Acid and Hydrogen Peroxide. This mixture is known as Piranha Solution and is extremely good at dissolving organic matter.

They then filled a tub with the solution and tried to dissolve a pig carcass with it. They performed that experiment on a controlled outdoor set in the desert.

What you would expect from Movie Acid:

  • It succesfully dissolved the pig carcass within 5 minutes. All that remained of it was some black sludge. Definitely very impressive.

What you would not expect from Movie Acid:

  • The chemical is a clear liquid which looks quite harmless when in a suitable container with nothing to dissolve. No weird colors, no bubbling, no glowing in the dark.
  • The experiment created a huge amount of smoke
  • The tub boiled over and spread acid all around. It was quite a mess.
  • The acid did almost no damage to fiberglass or wood.
  • (not mentioned in the episode) The solution can not be stored for prolonged amounts of time. It must be freshly prepared whenever you want to dispose of a red shirt or mook.
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    $\begingroup$ "Most acids are clear like water" is why someone had the bright idea to backlight it and make it green. Otherwise it's boring to look at. But green, hooboy you better believe that looks radioactive (incidentally green is associated with radioactive because that was the color that radium paint glows, and likely that same color was chosen for movie acid because of that association). $\endgroup$ – Draco18s May 30 '17 at 16:39
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    $\begingroup$ @Draco18s Or pink when Radium was used in cosmetics! $\endgroup$ – TripeHound May 31 '17 at 11:01
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    $\begingroup$ Oh hey someone asked why green is the color of poison today. Neat! $\endgroup$ – Draco18s Jun 2 '17 at 18:23
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    $\begingroup$ How can something so corrosive to flesh and bone do nothing to an organic fiber like wood? Maybe the finish on it? $\endgroup$ – cde Jun 3 '17 at 23:21
  • $\begingroup$ @cde Why different acids have different effects on different materials is an interesting question which you might want to ask on chemistry.stackexchange.com $\endgroup$ – Philipp Jun 5 '17 at 14:07
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  1. Dye acetone green.
  2. Heat it up until it's boiling.
  3. Pour it over expanded polystyrene.

Be very careful about the puddle of flammable vapors you are standing in.

The acid blood special effect in Alien was done in a similar manner.

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Liquid fluorine may have some of the aesthetic you want, but not the realism. Fluorine is a gas at well below room temperature, or even living temperatures. Instead, consider fuming acids. You can create fuming nitric acid and fuming sulfuric acid (oleum) by adding a counterion source to a saturated acid solution. This is a simplification, but the result is the desired acid, superconcentrated -- the observed 'concentration' is above 100%!

Fuming acids:

  1. Have a strange color.
  2. "Smoke" (fume) constantly in air.
  3. React violently with a great many things.

In my estimation, this is the closest you can get to comic-book acid IRL.

PS: From a chemical perspective, glowing would be worth a lot more bonus points than any of these other traits. You might be able to induce it in an acid solution via Cherenkov Radiation, if your acid vats are held over top of a nuclear reactor...

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    $\begingroup$ You can still get a vat of liquid fluorine to hang around for a time. Yes, it will eventually boil off but it will remain a liquid for a period of time. $\endgroup$ – Joe Kissling May 30 '17 at 20:33
  • $\begingroup$ That period of time would be exceedingly short. Fluorine's vapor pressure is enormous at livable temperatures, and even if you had one big enough to sit around, it wouldn't be much good for a vat to fall into; anybody in the vicinity would die from fume contact and inhalation before they got very far. Your skin would catch fire! $\endgroup$ – R. Barrett May 30 '17 at 20:55
  • $\begingroup$ Its vapor pressure is comparable to Nitrogen. I've worked with liquid nitrogen and with the proper container it can stand for a while. Yes, what does vaporize will set your skin on fire but so will anything that does fall into it. $\endgroup$ – Joe Kissling May 30 '17 at 21:29
  • $\begingroup$ If it's aesthetics you want, the pyrotechnics of liquid fluorine, ah, "vehemently interacting" with absolutely everything else on the periodic table that isn't a noble gas will be all you can hope to dream of. $\endgroup$ – Shadur Jun 1 '17 at 12:04
  • $\begingroup$ Red fuming nitric acid is pretty nasty (though I don't think it will liquefy people the way movie acid does) but more importantly people do keep large vats of the stuff sitting around: it's a standard oxidizer in rocket fuels. $\endgroup$ – Anne Jun 2 '17 at 11:52
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Hydrofluoric acid is a really, really nasty stuff (the nastiest ?), but it hasn't a gross green color (or glows for all I know). Still, it is really good at melting stuff (chemists working with it have a reputation of missing fingers...) and should produce bubbles and smoke while doing so.

I think you'll have trouble getting this green color, and the glowing is weird too, but I still have all of my fingers (not being a chemist myself), so I may be wrong.

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    $\begingroup$ Indeed, I didn't mean fingers gone from the acid alone, amputation following the damages is more correct. $\endgroup$ – Keelhaul May 30 '17 at 14:52
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    $\begingroup$ Generally things with fluorine in it are things to stay away from. Although hydrofluoric acid doesn't cause acid burns on contact, it generally penetrates deep without any visible effects for several hours (up to a day) at which point the damage is untreatable. And the only thing I know that'll make a chemist run away faster than the words "dioxygen difluoride" are the words "azidoazide azide." $\endgroup$ – Draco18s May 30 '17 at 14:58
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    $\begingroup$ I prefer to describe dioxygen difluoride using the descriptive chemical formula: FOOF. $\endgroup$ – supercat May 30 '17 at 18:38
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    $\begingroup$ Despite the impression you may get from Breaking Bad, HF is actually a really poor choice to "melt" or dissolve anything. It can cause some pretty nasty bone deformations and burns a relatively long time after exposure, but it's really nothing like other more reactive fluorine compounds or strong acids that can literally strip your flesh to the bone if you're not careful. $\endgroup$ – HopelessN00b May 30 '17 at 21:03
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Well if you want it orange instead of green it's a passable description of a highly concentrated aqua regia. Which, incidentally, is unstable and reacts with itself. It's also one of the few acids that can dissolve gold. The glowing is probably intentional back-lighting so it can be seen in the glass easier.

Wikipedia: https://en.wikipedia.org/wiki/Aqua_regia

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    $\begingroup$ The science behind why aqua regia dissolves gold is actually quite interesting. Aqua regia is a mixture of two different acids (which is why it reacts with itself) neither of which can dissolve gold on their own, but when put together each performs a different task necessary to break apart the gold-gold metalic bonds. $\endgroup$ – Draco18s May 30 '17 at 16:35
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How about if it glowed red? If that's acceptable, use lava. I suppose that's really not what you're looking for. Otherwise, you're out of luck.

Stuff doesn't "glow" unless it's reacting. So, to have a bottle on your shelf that's glowing requires it to be reacting with itself. A chemical reaction will quickly (proportionate to the intensity of the light emitted) deplete itself. Radioactive glow might work, if you don't mind becoming radioactive and/or dying of radiation poisoning...Some chemiluminescent systems are catalyzed by iron, so I can see a situation where such a system was put in acid and as it reacted with steel, a glow appeared. The systems I'm aware of use hydrogen peroxide which is fairly stable in acid, but would make the acid solution pretty nasty for the dye which is where the color comes from. Such a system would, I think, have to be stored as two separate components and mixed right before use.(Note that mixing oxidizers (H2O2) and organic chemicals is dangerous, do not do this at home, especially in highly corrosive (acidic) solution!).

The real problem with the movie acid is two-fold:

  1. The speed is totally unrealistic. Unless they made the door (or whatever) out of magnesium or some really reactive metal (not likely), it would take hours, days, weeks, or months to "eat through" a inch of the material

  2. The amount of acid is way too little. You figure that even if the acid liquid is 100% by weight active acid, then its molecular weight is going to be more than the atomic weight of the metal. This means that for every 1 pound of metal you want to "eat through" you are going to need two or more pounds of acid. A couple of drops doesn't just continue to eat down into the metal, sorry.

One last comment about the bubbling. When metal and acid react in water the water can decompose into hydrogen gas; it is the water, not the metal (nor the acid) that is bubbling. This is noteworthy because bubbling helps move the reaction products away from the surface and move more acid towards the surface but it requires that the acid liquid has enough water to do this bubbling, which dilutes the amount of acid available to react. Catch-22.

Finally, I should mention that "gooey" liquids have high viscosity and will be even slower to mix than water-thin solutions. The reaction is occurring at the metal's surface, and can only happen if the reaction products are moved away and "fresh" acid is moved in. High viscosity slows this even more.

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    $\begingroup$ Welcome to Worldbuilding! Consider adding formatting to your answer in order to avoid leaving readers with a big block of text ;). A poorly formatted answer could be disregarded despite being highly relevant. $\endgroup$ – Keelhaul May 30 '17 at 15:34
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    $\begingroup$ I went ahead and separated it into paragraphs for clarity. $\endgroup$ – maguirenumber6 May 31 '17 at 10:33
  • $\begingroup$ Another reason things can glow: en.wikipedia.org/wiki/Fluorescence $\endgroup$ – gmatht May 31 '17 at 15:27
  • $\begingroup$ Radioactive lighting at tolerable radiation levels exists though it is considered a gratitous risk these days - watch faces, cockpit instrument illumination in aircraft, some british telephones ... $\endgroup$ – rackandboneman May 31 '17 at 16:02
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Please note that F2 is a gas at room temperature. Its density is 1.7 grams per liter so to react with 1 pound of steel you'd need many gallons of it. And of course, if you were around many gallons of a toxic, corrosive gas then you'd be dead. Hydrofluoric acid is an even worse idea. It is a very weak (but very toxic) acid. It's so weak, in fact, that it doesn't attack skin much. It soaks right in (and through) skin. The bad news is that since it is very toxic, it will later kill much of the tissue that's been exposed to it. A guy I knew spilled just a bit on his pants, and they had to remove a chunk of his leg the size of a tennis ball. They use HF to coat some metals to make it less susceptible to corrosion, its not going to work for your purpose. Period.

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    $\begingroup$ While you are correct in your assessment, this doesn't answer the question asked. $\endgroup$ – sphennings May 30 '17 at 15:46
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    $\begingroup$ This does not provide an answer to the question. Once you have sufficient reputation you will be able to comment on any post; instead, provide answers that don't require clarification from the asker. - From Review $\endgroup$ – James May 30 '17 at 16:07
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    $\begingroup$ @James This answer provides an answer - it is not F2 or HF. Not the best kind of answer but definitely valuable input in given situation considering other answers. $\endgroup$ – MolbOrg May 30 '17 at 17:10
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    $\begingroup$ @MolbOrg I agree that it is useful information but it doesn't address the question, just a problem with the question. It makes far more sense as a comment to me. $\endgroup$ – James May 30 '17 at 19:13
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    $\begingroup$ @James essential answer to the OP's question is No. No without any options. The rest of answers is how to mimic that, and this is how not to mimic that. $\endgroup$ – MolbOrg May 30 '17 at 19:47
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Anhydrous acids such as Titanium Tetra Chloride are really nasty and can make short work of organics. They don't really attack metals while in an anhydrous state but once exposed to water or oxygen it condenses into HCl and perchloric acid. It's very smoky, and is twice as dense as air so it rolls across the ground, very creepy to see in person. It's generally off-white in color, but titanium accepts pigment quite well. So for the traditional mad scientist who must have green, a little copper sulfate and you got green :).

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