# So - what's the strongest acid? **URL:** \ **Category:** Factual Questions\ **Created:** [September 28, 2002, 5:21am UTC](https://boards.straightdope.com/t/so-whats-the-strongest-acid/129990 "2002-09-28T05:21:44Z")\ **Posts on this page:** 20\ **Page:** 2
**Author:** ![\_etalhea](https://avatars.discourse-cdn.com/v4/letter/_/779978/32.png) [@\_etalhea](https://boards.straightdope.com/u/_etalhea)\ **Post date:** [September 29, 2002, 2:02am UTC](https://boards.straightdope.com/t/so-whats-the-strongest-acid/129990/21 "2002-09-29T02:02:09Z")
> [@](#): > > \*Originally posted by alice\_in\_wonderland \* > \*\*I need to qualify this. I know that hydrogen flouride dissasociates completely and has a really high proton-donating capability and all that; however, HF is stored in _ **PLASTIC!?!?** _ containers. That sounds like a pretty wimp-ass acid to me. > \*\* ummm, commenting on the OP here, plastic is **Inert!**. Concentration of the acid really doesn’t matter. It’s inert. There’s nowhere to donate protons TO. It’s all sewn up. Sheesh, didn’t anyone here go to engineering school? ---
**Author:** ![artemis](https://avatars.discourse-cdn.com/v4/letter/a/91b2a8/32.png) [@artemis](https://boards.straightdope.com/u/artemis)\ **Post date:** [September 29, 2002, 2:06am UTC](https://boards.straightdope.com/t/so-whats-the-strongest-acid/129990/22 "2002-09-29T02:06:14Z")
> [@](#): > > \*Originally posted by SHAKES \* > \*\* > As for the strongest acid? I can’t remember the name of the stuff but all I know is; if it goes past its experation date we have to call the bomb squad in to get rid of the stuff. Its so dangerous that they have to use a robot to go in and get it. then they clear the parking lot or take it to a field then explode it. And oh yeah, all they have to do to explode it is drop the freaking bottle. \*\* You’re thinking of picric acid, which is not a very strong acid at all - just unstable if it dries out. ---
**Author:** ![Lumpy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lumpy/32/446_2.png) [@Lumpy](https://boards.straightdope.com/u/Lumpy)\ **Post date:** [September 29, 2002, 2:48am UTC](https://boards.straightdope.com/t/so-whats-the-strongest-acid/129990/23 "2002-09-29T02:48:19Z")
There are so-called “superacids”, the most well known of which is a solution of antimony hexafloride dissolved in hydrogen fluoride. [Here](http://www.cmm.upenn.edu/research/acid.html) is a link to one site about it. I don’t know exactly what technical definition of strength they use, but apparently this stuff can catylize reactions that even the strongest ordinary acids can’t. I have no idea how it compares in bulk material corrosiveness. ---
**Author:** ![cdhostage](https://avatars.discourse-cdn.com/v4/letter/c/c6cbf5/32.png) [@cdhostage](https://boards.straightdope.com/u/cdhostage)\ **Post date:** [September 29, 2002, 2:52am UTC](https://boards.straightdope.com/t/so-whats-the-strongest-acid/129990/24 "2002-09-29T02:52:32Z")
Heck, if you want to talk about most corrosive stuff, there’s flourine gas. ---
**Author:** ![alice\_in\_wonderland](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/alice_in_wonderland/32/176_2.png) [@alice\_in\_wonderland](https://boards.straightdope.com/u/alice_in_wonderland)\ **Post date:** [September 29, 2002, 5:46am UTC](https://boards.straightdope.com/t/so-whats-the-strongest-acid/129990/25 "2002-09-29T05:46:30Z")
Humm - all very interesting, but I still don’t know how to get the crap my roommate left, out of the bottom of my frying pan… No - really. I suppose I’m mostly interested in which acid is the most distructive - as in - if you spill 3 mls of acid X vs. 3 mls of acid Y, these would be the results, the hole in the table would be this big - your skin would be gone in this many seconds, etc. It sounds like nitric is pretty hardcore stuff, and actually the HF bone eating deal sounds pretty nasty too - I honestly had no idea this was such a complicated question. No wonder my Chem 10 teacher blew me off when I asked. ---
**Author:** ![scm1001](https://avatars.discourse-cdn.com/v4/letter/s/c4cdca/32.png) [@scm1001](https://boards.straightdope.com/u/scm1001)\ **Post date:** [September 29, 2002, 10:13am UTC](https://boards.straightdope.com/t/so-whats-the-strongest-acid/129990/26 "2002-09-29T10:13:24Z")
The problem in measuring acid strength is that in water many acids appear 100% dissociated - e.g. all their hydrogen ions are liberated and are free to react. Thus too a first approximation, all strong acids in water have the same strength. Its only when you get out of water systems into organic solvents that you can measure differences between say hydrochloric acid and sulfuric acid. Another problem is that many acids will react in different ways, e.g perchloric as an oxidizer, hydroiodic acid as a reducer, hydrogen flluoride will attack glass. In each case it is not the acid portion that is reacting, but the counterion (fluoride, perchlorate etc) However, there are some acid systems that will react with almost anything. The superacids as Lumpy states are like that. As for what is the most destructive - it depends on what you are looking. Some acids are failry selective in what they will attack (gold, glass) etc. As far as organic matter goes, fuming sulfuric acid will probably eat through your arm as fast as anything. ---
**Author:** ![Squink](https://avatars.discourse-cdn.com/v4/letter/s/b5e925/32.png) [@Squink](https://boards.straightdope.com/u/Squink)\ **Post date:** [September 29, 2002, 3:23pm UTC](https://boards.straightdope.com/t/so-whats-the-strongest-acid/129990/27 "2002-09-29T15:23:59Z")
> [@](#): > > I suppose I’m mostly interested in which acid is the most distructive - as in - if you spill 3 mls of acid X vs. 3 mls of acid Y, these would be the results Chromic acid, made by mixing potassium dichromate with concentrated sulfuric acid, is what you want. It combines all the dehydrating properties of H[sub]2[/sub]SO[sub]4[/sub] with an oxidizer more powerful than HNO[sub]3[/sub]. Here’s a commercial description: [Chromerge®](http://www.macbicnj.com/glsblwequip/10415.htm) Microscopic droplets of this acid are particularly adept at slipping out of their containers and burning pencil sized holes in blue jeans. As an added bonus, the stuff is highly carcinogenic :eek: ---
**Author:** ![alice\_in\_wonderland](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/alice_in_wonderland/32/176_2.png) [@alice\_in\_wonderland](https://boards.straightdope.com/u/alice_in_wonderland)\ **Post date:** [September 29, 2002, 3:54pm UTC](https://boards.straightdope.com/t/so-whats-the-strongest-acid/129990/28 "2002-09-29T15:54:10Z")
Yowza! Load me up with some of that **Chromerge** would ya - I’m sure all my cleaning problems would be solved with that… Seriously - thanks for all the info guys - this has been really enlightening - I never went past highschool with my Chemistry. ---
**Author:** ![Myrr21](https://avatars.discourse-cdn.com/v4/letter/m/e495f1/32.png) [@Myrr21](https://boards.straightdope.com/u/Myrr21)\ **Post date:** [September 29, 2002, 6:16pm UTC](https://boards.straightdope.com/t/so-whats-the-strongest-acid/129990/29 "2002-09-29T18:16:50Z")
Part of the problem is what you intend to dissolve. For example, the oils in your skin will repel a lot of “strong” acids long enough for a good washing to reduce the damage to an irratating burning sensation for 20 minutes or so. I’ve spilled some incredibly nasty acids on my arm and come away with only an “ow, that fugging hurt” reaction. On the other hand, some really strong organic acids can get through this barrier much more easily, and will therefore burn you a lot worse initially. Of course, if you hold your arm in long enough, it becomes a moot point. A related example: if you wash glacial acetic acid off yourself quickly, you probably won’t even feel it (it’s not a very strong acid), but if you got enough on you, your skin will harden and crack off in a few days. I’ve had this happen (of course, I then spilled 20% trifluoroacetic acid in the cracked spot…damn did that hurt). ---
**Author:** ![dougie\_monty](https://avatars.discourse-cdn.com/v4/letter/d/439d5e/32.png) [@dougie\_monty](https://boards.straightdope.com/u/dougie_monty)\ **Post date:** [September 29, 2002, 8:59pm UTC](https://boards.straightdope.com/t/so-whats-the-strongest-acid/129990/30 "2002-09-29T20:59:27Z")
I have noted that _boric acid,_ H3BO3, is one of the weakest acids; Asimov described it thus: “It is such a weak acid that it may as well be considered no acid at all. It is a very mild antiseptic and is sometimes dissolved in water and used as an eyewash. If the delicate membranes of the eye can stand it, you can see how weak an acid it must be.” _(Building Blocks of the Universe,_ about 1958) ---
**Author:** ![spingears](https://avatars.discourse-cdn.com/v4/letter/s/ebca7d/32.png) [@spingears](https://boards.straightdope.com/u/spingears)\ **Post date:** [August 25, 2003, 8:21pm UTC](https://boards.straightdope.com/t/so-whats-the-strongest-acid/129990/31 "2003-08-25T20:21:10Z")
Concentrated Sulphuric acid is stored and shipped in steel tanks. When diluted it gets nasty and has to be contained in lead lined tanks. I have seen my boss on more that one ocassion reach bare handed into a vat of concentrated sulphuric acid to retrieve a part, but he immediately flush his arm under a copious stream of fast flowing water. ---
**Author:** ![chaoticbear](https://avatars.discourse-cdn.com/v4/letter/c/f07891/32.png) [@chaoticbear](https://boards.straightdope.com/u/chaoticbear)\ **Post date:** [August 25, 2003, 10:26pm UTC](https://boards.straightdope.com/t/so-whats-the-strongest-acid/129990/32 "2003-08-25T22:26:30Z")
magic trick… this thread is back from the dead ---
**Author:** ![antechinus](https://avatars.discourse-cdn.com/v4/letter/a/fbc32d/32.png) [@antechinus](https://boards.straightdope.com/u/antechinus)\ **Post date:** [August 25, 2003, 10:58pm UTC](https://boards.straightdope.com/t/so-whats-the-strongest-acid/129990/33 "2003-08-25T22:58:05Z")
I could have swore **Desmostylus** posted links to [this thread](http://boards.straightdope.com/sdmb/showthread.php?s=&threadid=155457) and [this thread](http://boards.straightdope.com/sdmb/showthread.php?s=&threadid=206675) on the same question. ---
**Author:** ![wychunter](https://avatars.discourse-cdn.com/v4/letter/w/439d5e/32.png) [@wychunter](https://boards.straightdope.com/u/wychunter)\ **Post date:** [March 21, 2012, 3:34am UTC](https://boards.straightdope.com/t/so-whats-the-strongest-acid/129990/34 "2012-03-21T03:34:14Z")
> [@Shade](#): > > It’s been a while since I did chemistry, but isn’t pH defined as a logarithmic measure of the concentration of hydogen ions, ie. protons? Then pure protons would technically be acidic. > > Of course, there’d be more immediate problems, like a large explosion. But it’d be a) low pH and b) dangerous, which seems to be what’s desired. pH is the concentration of Hydronium (H3O) ions that are made as an acid reacts. But yes it is logarithmic. ---
**Author:** ![Joey\_P](https://avatars.discourse-cdn.com/v4/letter/j/919ad9/32.png) [@Joey\_P](https://boards.straightdope.com/u/Joey_P)\ **Post date:** [March 21, 2012, 3:51am UTC](https://boards.straightdope.com/t/so-whats-the-strongest-acid/129990/35 "2012-03-21T03:51:09Z")
The rare and elusive Double Zombie thread. At least Springears stuck around after he reanimated it. ---
**Author:** ![johnpost](https://avatars.discourse-cdn.com/v4/letter/j/f17d59/32.png) [@johnpost](https://boards.straightdope.com/u/johnpost)\ **Post date:** [March 21, 2012, 3:52am UTC](https://boards.straightdope.com/t/so-whats-the-strongest-acid/129990/36 "2012-03-21T03:52:13Z")
magic trick… this thread is back from the dead again. get me some NaOH ---
**Author:** ![si\_blakely](https://avatars.discourse-cdn.com/v4/letter/s/d9b06d/32.png) [@si\_blakely](https://boards.straightdope.com/u/si_blakely)\ **Post date:** [March 21, 2012, 10:32am UTC](https://boards.straightdope.com/t/so-whats-the-strongest-acid/129990/37 "2012-03-21T10:32:24Z")
> [@johnpost](#): > > get me some NaOH The one thing I do remember from my Uni labs is always use copious amounts of a weak base (NaHCO[sub]3[/sub]) to neutralise strong acid - you can safely overshoot and don’t get a violent reaction that will splatter acid/and or base all over the victim/lab/rescuer. Zombie acids, on the other hand, can’t be dealt with without splatter ;). Si ---
**Author:** ![WarmNPrickly](https://avatars.discourse-cdn.com/v4/letter/w/d78d45/32.png) [@WarmNPrickly](https://boards.straightdope.com/u/WarmNPrickly)\ **Post date:** [March 21, 2012, 11:23am UTC](https://boards.straightdope.com/t/so-whats-the-strongest-acid/129990/38 "2012-03-21T11:23:25Z")
> [@wychunter](#): > > pH is the concentration of Hydronium (H3O) ions that are made as an acid reacts. But yes it is logarithmic. It’s defined as the negative log of the concentration of hydrogen ions (or protons). It’s true that free protons don’t exist in solution, but neither do free hydronium ions. If you make it a 5% ethanol solution, are you going to discount the CH3CH2OH2+ ions? The strongest common acid is probably sulfuric acid. Any acid stronger is, by definition, a superacid. Up thread somebody mentioned their boss sticking their hand in it. You might get away with that, because there is some kinetic issue in the standard 97% form. You can bet that when its mixed with water it generates a hell of a lot of energy though. Pure 100% sulfuric probably gets very reactive. I’ve worked with 120% Sulfuric acid (that’s 100% sulfuric with 20% free SO3), and that stuff is crazy. I’ve also worked with chlorosulfonic acid, and that’s even crazier. Triflic acid is another super acid. Then there is fluorosulfonic antimonypentafluoride, aka “Magic Acid”. I’ve never had the pleasure of working with that. Beyond that, you can get exotic acids being synthesized in research labs. All of those acids are superacids. In water though, those acids are all deprotonated. They are no stronger than the same concentration of hydrochloric acid. ---
**Author:** ![Derleth](https://avatars.discourse-cdn.com/v4/letter/d/b9e5f3/32.png) [@Derleth](https://boards.straightdope.com/u/Derleth)\ **Post date:** [March 21, 2012, 1:23pm UTC](https://boards.straightdope.com/t/so-whats-the-strongest-acid/129990/39 "2012-03-21T13:23:42Z")
> [@WarmNPrickly](#): > > If you make it a 5% ethanol solution, are you going to discount the CH3CH2OH2+ ions? Only if I’m buying them wholesale. ---
**Author:** ![SunSandSuffering](https://avatars.discourse-cdn.com/v4/letter/s/ee7513/32.png) [@SunSandSuffering](https://boards.straightdope.com/u/SunSandSuffering)\ **Post date:** [March 21, 2012, 3:49pm UTC](https://boards.straightdope.com/t/so-whats-the-strongest-acid/129990/40 "2012-03-21T15:49:30Z")
Strongest acid = xenomorph blood [Previous page](https://boards.straightdope.com/t/so-whats-the-strongest-acid/129990.md?page=1) [Next page](https://boards.straightdope.com/t/so-whats-the-strongest-acid/129990.md?page=3)