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NeutralIon
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Bad Chemistry on TV
Its really amazing what they can do with chemicals on TV!
The episode of CSI:Miami last night had the deceased victim floating in a swimming pool full of NaOH. The concentration was strong enough to eat
through glass.
When the CSI guys realized it was an alkali they knew they needed to neutralize it in order to retrieve the body. So they send one of the team to the
local grocery store for vinegar. They proceed to pour the vinegar from gallon jugs into the pool dropping the pH from almost 13 [just after they
started adding the vinegar] to exactly 7.0 -- all within a few seconds, and without any stirring.
Now, I'm no expert on chemistry but I do know that vinegar is, at best, 5% acetic acid and acetic acid is a weak acid so even with equal molar amounts
of NaOH and CH3COOH you would not get down to 7.0. To get that low you would need a large excess of vinegar -- somewhere around 20 times the volume
of water in the pool!!! Yet they poured this all in from gallon jugs in under a minute and the pool did not overflow.
Somebody in the Miami area please check your local grocery stores and find out what brand of vinegar they are selling.
Knowledge is Good
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Saerynide
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I was thinking more like the body should have turned into soap by the time the cops got there
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BromicAcid
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Remember that pH is a logarithmic scale. A 0.5% solution can have a pH of 13-14. That's only 5 g NaOH/ Kg of water (w/w). Point being that it
doesn’t take much sodium hydroxide to change the pH quite a bit.
Assuming average pool size of 20 x 40 ft and 5.5 ft deep, volume is 33000 gallons, is equivalent to 124918 L so assuming 1.0 Kg/L density that gives
124918 Kg of solution which contains 624 Kg NaOH. Converting to mols, 1561 mols NaOH. Molarity of store bought vinegar ca. 0.8 M so doing the math
and just trying to neutralize the sodium hydroxide and ignoring the buffer effect of the acetate anion...
1951 L of vinegar will do it. Or, 515 of those 1 gallon containers. In the scheme of things, that's only 1.5% the existing volume in the pool. So,
I wouldn't say overflowing but it would take some time to add for sure. And I think they would have to visit quite a few stores to get that much
vinegar. Considering the dilution of it though I wouldn't worry too much about mixing, by the time it was all added from 1 gallon containers with the
circulation pumps in a pool it should all be pretty good. By the way, the bleach we use in the kitchen has a similar pH and I've know lots of people
who will clean whole kitchens using straight bleach with a sponge and no gloves. How badly was the glass eaten?
I've seen plenty of bad chemistry on TV, I would consider this an exaggeration, like in cooking shows when they cut to the finished product but not
anything egregious.
[Edited on 5/13/2009 by BromicAcid]
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NeutralIon
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Bromic --
I think you are right -- I somewhat overestimated the amount of vinegar needed.
But your analysis may be a bit low. Adding 1561 moles of acetic acid in the form of 1951 L of vinegar only drops the pH down to the equivalence point
which for the chemicals involved is about 9.2. On the show they did show the pH going to 7.0 so some additional acid would be needed to get there.
Either way -- a lot more vinegar than they showed.
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kclo4
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Another example is the anti-smoking commercials. They have the symbol for lead as PB, not Pb. They also suggest that it is found in high enough
concentrations in cigarettes to worry about, which seems stupid since I would bet tomatoes would have similiar concentrations.
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indigofuzzy
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Similarly, the anti-cigarette ads talking about Sodium Hydroxide in cigarettes. Hmm, those of us who bother to read labels know it's in eye drops too.
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497
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Hah that reminds me of the anti-meth posters that are trying to tell you that the various reagents and solvents used to manufacture it are actually
in the final product. '"Oh my god there's lye and paint stripper in my meth!" It's hilarious.
Its amazing how people have such a hard time understanding that all the various "ingredients" are simply used to manipulate a specific molecule,
rather than being tossed together and magically making a mixture that happens to get you high..
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Waffles
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On the other hand, for basement-made meth (basically all of it), I would expect you get a slight to not-so-slight amount of impurities. Maybe not
volatile-as-hell paint stripper, but certainly unpleasantness. Not that the unpleasantness could easily be worse than the meth itself, but ya know.
\"…\'tis man\'s perdition to be safe, when for the truth he ought to die.\"
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TheOrbit
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that exceeding the buffering effect 
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everythingischemistry
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The water supplies in the UK still extensively have lead pipes from the community mains to each home. We don't all fall over with lead poisoning. Most
people don't even know their water comes through lead pipes. I've handled lead without gloves, etc many times (in the form of fishing weights) and not
bothered to wash my hands afterwards before eating/drinking. Nothing bad happened. Of course I wouldn't want to EAT the lead or inhale it (in any sort
of visible quantity, some idiots actually smoked cannabis with visible bits of lead in it according to news reports) but it's not AS dangerous as most
people think.
Bleach isn't that dangerous on it's own either. You could have a swig from the bottle (assuming it's just sodium hypochlorite, which most "bleach" in
the UK isn't) and while you will sure as hell wish you didn't (don't try this at home kids) it's unlikely to kill without having a fair bit.
Personally I would wear gloves with this one but I don't bother to wash my hands after holding the bleach bottle or anything if I was just using it to
sanitize something, despite the overblown warnings on the label.
People get so scared of the "chemicals" these days. It's a pity the powers that be are so paranoid of having an enlightened society they fuel this
nonsense. They are doubly stupid as 1) There is a thing called the army which will always have bigger and badder stuff than everyone else so the
government as a "team" has nothing to concern itself over and 2) If someone really, really, really wants to kill the president/prime minister/anyone
else and isn't a complete idiot then they are going to. The IRA have almost killed our PM on a few occasions and the technology they used while not
available in a store near you isn't very advanced either and not something you can stop people doing if they are really dead set on doing it.
Doesn't CSI get a lot of flack for doing things badly? I've read in other pieces of fiction before bemoaning the "CSI effect" where juries and others
have unrealistic expectations of forensics because of CSI but I don't watch it myself and don't know how valid these criticisms are, anyone? Are CSI
proponents of bad science often?
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User
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CSI just sucks and creates false ideas about the whole subject.
I have seen people on TV say that cigarettes contain carbon monoxide.
I mean what the fuck, it seems to be allowed to speak about things that one doesnt know shit about.
False ideas and throwing it on scare politics.
What a fine day for chemistry this is.
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DJF90
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Cigarettes DO contain carbon monoxide! I'm pretty sure if you look at a cigarette packet you'll see some numbers for nicotine and carbon monoxide, per
cigarrette. IIRC carbon monoxide is generally about 10mg, and nicotine about 2mg? But its been a long time since I've seen a cigarette packet as I
dont smoke. I'm pretty sure this information is on most products, I know for sure that Lambert&Butler and also SilkCut divulge this information.
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ammonium isocyanate
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Are you sure that cigarettes actually CONTAIN carbon monoxide, or that it is just produced durning combustion. I can't really see even 10mg of CO
trapped in the cigarrete itself.
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chemrox
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The almost routine filmsci presentation is glassware with colored liquid in weird places like the condenser coils or an anti-foaming device such as in
Air America and there are much worse examples I just can't recall right now..anyway, it embarasses
"When you let the dumbasses vote you end up with populism followed by autocracy and getting back is a bitch." Plato (sort of)
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hissingnoise
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Quote: Originally posted by everythingischemistry  | | Nothing bad happened. Of course I wouldn't want to EAT the lead or inhale it (in any sort of visible quantity, some idiots actually smoked cannabis
with visible bits of lead in it according to news reports) but it's not AS dangerous as most people think. |
If water in lead pipes falls below a certain pH some lead will dissolve and such water will have high toxicity---any underestimation of lead's
toxicity is foolish as lead is an insidious cumulative poison. . .
The NaOH in commercial bleach is much more toxic than NaClO, but solutions of NaClO disproportionate so that these solutions normally contain NaCl +
NaClO + NaClO3.
Chlorates were once used as an anti-bacterial in throat lozenges. . .
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ammonium isocyanate
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| Quote: Originally posted by BromicAcid |
Assuming average pool size of 20 x 40 ft and 5.5 ft deep, volume is 33000 gallons, is equivalent to 124918 L so assuming 1.0 Kg/L density that gives
124918 Kg of solution which contains 624 Kg NaOH. Converting to mols, 1561 mols NaOH.
[Edited on 5/13/2009 by BromicAcid] |
I just noticed this, and maybe I'm totally off here, but the molar mass of NaOH is ~40g, so 624kg would make about 15,610 mols NaOH.
Am I missing something?
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chloric1
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Lead is more soluble in soft water than hard water. IRC England has some impressive limestone deposits so I would think the water pretty "hard" with
calcium and magnesium bicarbonates. Correct me if I am wrong about England's mineralogy
We need to get the message out to the powers that be that this oppresive and restrictive society is actually more insecure and unsafe then when we had
relative freedom in years past.
Fellow molecular manipulator
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MagicJigPipe
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I watched an episode of some CSI show and noticed that they claimed--wait, no, it was House (a doctor TV show)--that some guy had been killed by
mixing ammonia and bleach and breathing in too much chlorine gas.
This seems to be a common mistake. Is there any chlorine gas released by such a mixture? I know it can't be much because I have tried it on
a small scale (and noticed no color and little Cl2 smell; not that I was going out of my way to smell it).
Also less common (but worse) is that ammonia and bleach will produce "mustard gas".
Even worse is that gasoline and "moth balls" produces nitroglycerin.
"There must be no barriers to freedom of inquiry ... There is no place for dogma in science. The scientist is free, and must be free to ask any
question, to doubt any assertion, to seek for any evidence, to correct any errors. ... We know that the only way to avoid error is to detect it and
that the only way to detect it is to be free to inquire. And we know that as long as men are free to ask what they must, free to say what they think,
free to think what they will, freedom can never be lost, and science can never regress." -J. Robert Oppenheimer
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Formatik
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No Cl2 if there is an excess of ammonia which would react with it. I know interactions of aq. -ClO and NH4 salts is somewhat complex, those I know can
release some Cl2.
In one of my old favorite shows called the Pretender, there was an episode where a stalker would take pictures of his stalking victims. Then he took
the pictures and dripped an acid to dissolve some portion of the picture, it just ate right through the picture.
I don't think such a compound exists . Maybe HSbF6.
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chloric1
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| Quote: Originally posted by Formatik | No Cl2 if there is an excess of ammonia which would react with it. I know interactions of aq. -ClO and NH4 salts is somewhat complex, those I know can
release some Cl2.
In one of my old favorite shows called the Pretender, there was an episode where a stalker would take pictures of his stalking victims. Then he took
the pictures and dripped an acid to dissolve some portion of the picture, it just ate right through the picture.
I don't think such a compound exists . Maybe HSbF6. |
I used to take a Q-tip soaked in concentrated HCl and touch photos and poloroids I did not like. It only removed the image and noting more.
I also see too many programs using dry ice in brightly colored liquids to cause room temperature boiling and plumes of mysterious fog.
Fellow molecular manipulator
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Elawr
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I liked the one on "Breaking Bad" where, having recieved orders to dispose of a corpse, some idiot places the decedent in the upstairs bathtub and
adds a large quantity of conc. HF. THe bathtub dissolves and the carcass soon falls through the floor into the downstairs hallway. It was unclear as
to what effect the HF fumes had on the dimwitted perpetrater while splashing the acid all around in the enclosed bathroom space!
[Edited on 25-7-2009 by Elawr]
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kclo4
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Also on breaking bad, I believe he had a large crystal of mercury fulminate.. sounds a bit impossible, they only recently discovered its crystal
structure IIRC.
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497
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Yeah that mercury fulminate feature was entertaining.. Convenient how it happened to look identical to the crystal meth...
I was just waiting for him to try crushing a crystal up with the butt of his knife like he did before... That wouldn't have been pretty..
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JohnWW
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| Quote: Originally posted by MagicJigPipe | I watched an episode of some CSI show and noticed that they claimed--wait, no, it was House (a doctor TV show)--that some guy had been killed by
mixing ammonia and bleach and breathing in too much chlorine gas. This seems to be a common mistake. Is there any chlorine gas
released by such a mixture? I know it can't be much because I have tried it on a small scale (and noticed no color and little Cl2 smell; not that I
was going out of my way to smell it). (cut)
Even worse is that gasoline and "moth balls" produces nitroglycerin. |
Mixing ammonia and hypochlorite bleach would probably result in chloramines, NH2Cl and NHCl2; and, if an excess of bleach is used, nitrogen
trichloride, NCl3, which is a dangerously unstable explosive (too dangerous to use commercially) as the French discoverer, Dulong, found out.
Gasoline is a mixture of low to medium weight hydrocarbons (unless alcohol has been added) with about 5 to 12 C atoms, with the branched-chain
saturated aliphatic species obtained by catalytic cracking with addition of H2 to unsaturated species being most valued; while mothballs are either
naphthalene, C10H8, or dichlorobenzenes (especially the para isomer), which smell similar. The mothballs would simply dissolve in the gasoline.
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ammonium isocyanate
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I saw that House episode and laughed. Normally I like House, but I have found a few errors lately. One of them was the chloramine one. Another I
noticed that in one episode they did the standard tested for amyloidosis but skipped the addition of KMnO4, yet were still able to see that it was
amaloid AA.
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