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In the "Cat's in the Bag..." episode of Season 1 of "Breaking Bad," characters are shown with 4 gallon-jugs of Hydrofluoric Acid that they use to dissolve 2 adult corpses. Chemistry is a major plot device in the show and it seems like they go to some effort to keep those elements based in reality.

According to this article, hydrofluoric acid is a good choice for your body-melting needs. But if a bath is usually around 200 liters (50 gallons), could you really do it with just a few (5-10 liters, 2-4 gallons) of acid?

It's worth pointing out that for the purposes of this question, "dissolve" is defined as "creating a toilet-flushable slurry."

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    I don't think the claim, as questioned, is notable. They actually used enough acid to, along with the body, fill a 55-gallon barrel. That's a LOT MORE than 2-4 gallons. – Flimzy Jun 23 '13 at 19:14
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    I don't think this question deserves to have a negative score. – Sklivvz Jun 23 '13 at 20:31
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    @LarryOBrien: Remember Walter's instructions to Jesse to buy large plastic tubs? I think it's safe to assume they were planning to use large quantities (> 4 gallons) of acid. I also think the first time a body was dissolved, the quantity of acid used was very ambiguous. I don't think it's possible to conclude they used only 2-4 gallons. – Flimzy Jun 23 '13 at 20:54
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    Not an answer, but please don't play with HF at home or school... HF is unusually dangerous because it soaks through skin, reacts exothermically with bone venting H2, and binds quickly to Ca and Mg in fluids making the body fatally deficient -- research safety policies are an issue at many college campuses. web.utk.edu/~ehss/training/has.pdf – Paul Jun 24 '13 at 4:59
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From chemistry.stackexchange.com:

Hydrofluoric acid is toxic and corrosive, but actually isn't that strong of an acid compared to other hydrohalic acids; the fluorine has a very good orbital overlap with hydrogen and is also not very polarizable, therefore it resists to readily donate its proton. Hydrochloric acid is much stronger, and as it has several uses from pH-balancing pool water to preparing concrete surfaces, it's available by the gallon from any hardware store. However, it isn't very good at dissolving bodies either; while it will eventually work by breaking down the connective tissues, it will make a huge stink and take several days to dissolve certain types of tissues and bones.

The standard body-dissolving chemical is lye aka sodium hydroxide. The main source is drain clog remover, because most drain clogs are formed by hair and other bio-gunk that accumulates naturally when humans shower, exfoliate etc. It works, even though the body's overall chemistry is slightly to the basic side of neutral (about 7.35-7.4), because the hydroxide anion is a strong proton acceptor. That means that it strips hydrogen atoms off of organic molecules to form water (alkaline hydrolysis, aka saponification), and as a result, those organic molecules are turned into simpler molecules with lower melting points (triglycerides are turned into fatty acids, saturated fats are dehydrogenated to form unsaturated fats, alkanes become alcohols, etc). Sodium hydroxide is also a ready source of the sodium ion; sodium salts are always water-soluble (at least I can't think of a single one that isn't). The resulting compounds are thus either liquids or water-soluble alcohols and salts, which flush down the drain. What's left is the brittle, insoluble calcium "shell" of the skeleton; if hydrolyzed by sodium hydroxide, the resulting calcium hydroxide ("slaked lime") won't dissolve completely but is relatively easy to clean up.

  • What about oleum? (Fuming Sulphuric Acid) – Tim Mar 22 '15 at 12:40
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It isn't the amount of HF that is notable it is whether HF will work at all in this context. HF sounds like a good way to dissolve bodies as it has a fearsome and dangerous reputation in chemistry. But that reputation is based on the fact that it is a dangerous biological poison not on its ability to "dissolve" flesh. It is, in fact, a weak acid and not that good as a way to turn flesh into a flushable mush.

From my answer on the chemistry.se site (explaining the script choice):

I think the use of Hydrofluoric Acid was script-driven rather than fact driven: it sounds scary rather than being a good choice. Also it allows for the possibility of the darkly comic bathtub scene where the acid dissolves a ceramic bath because Jessie ignores Walter's instructions (which establishes Walter's expertise and Jessie's lack of it).

Moreover, we don't have to rely on theory here, the experiment has been done. Periodic Videos tested the idea using raw chicken legs and several flesh-dissolving alternatives. This video shows that, while HF has some remarkable effects on flesh, dissolving it into a mush isn't something it does quickly.

Incidentally, chemistry.se tagged this, amusingly, as everyday-chemistry.

  • This would fit with the show's habit of changing details of how certain criminal acts are performed (most notably, cooking meth). – KSmarts Mar 24 '15 at 17:04

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