TRANSCRIÇÃO 🔗
WEBVTT
1
00:00:01.379 --> 00:00:06.179
We're heading back to Breaking Bad. One of the most
2
00:00:06.240 --> 00:00:09.609
memorable scenes in Breaking Bad involved Jesse Pinkman, a bathtub,
3
00:00:09.640 --> 00:00:14.150
and a spectacular misunderstanding of chemistry. Walter Wright has instructed
4
00:00:14.210 --> 00:00:17.089
Jesse to use hydrofluoric acid to dispose of a body.
5
00:00:17.170 --> 00:00:20.329
Jesse ignores the warning about choosing an appropriate container and
6
00:00:20.410 --> 00:00:25.469
uses an upstairs bathroom instead, or bathtub. Later, the ceiling collapses,
7
00:00:25.510 --> 00:00:28.870
sending a grotesque mixture of debris and biological material crashing
8
00:00:28.890 --> 00:00:33.890
into the hallway below. It's horrifying, dark, comedic, and apparently
9
00:00:33.909 --> 00:00:39.340
a demonstration of hydrofluoric acid's incredible power. But how much
10
00:00:39.399 --> 00:00:43.640
of it is actually true or scientifically accurate? First, hydrofluoric
11
00:00:43.740 --> 00:00:47.280
acid is a generally dangerous chemical. However, the danger comes
12
00:00:47.299 --> 00:00:50.380
from some unusual properties that distinguish it from more familiar acids.
13
00:00:50.520 --> 00:00:53.329
Most people associate the acid's strength with how aggressively a
14
00:00:53.350 --> 00:00:57.369
substance damages tissue. But in chemistry, acid strength describes how
15
00:00:57.630 --> 00:01:02.229
readily an acid releases hydrogen ions in solutions. Hydrofluoric acid
16
00:01:02.270 --> 00:01:04.609
is technically classified as a weak acid because it is
17
00:01:04.670 --> 00:01:08.349
not completely disassociated in water. Now, it doesn't make it
18
00:01:08.409 --> 00:01:12.159
safe either. Unlike many other corrosive substances, hydrofluoric acid can
19
00:01:12.189 --> 00:01:16.680
penetrate deeply into tissue. Fluoride ions can interfere with essential
20
00:01:16.719 --> 00:01:21.739
biological processes, including those involving calcium and magnesium. This can
21
00:01:21.780 --> 00:01:26.079
produce several local injuries and serious exposures, potentially fatal disturbances.
22
00:01:27.030 --> 00:01:31.489
A person exposed to hydrofluoric acid may initially experience surprisingly
23
00:01:31.510 --> 00:01:36.000
little pain depending on the concentration and circumstances. What about
24
00:01:36.030 --> 00:01:40.219
dissolving an entire human body? Human tissue is not a
25
00:01:40.319 --> 00:01:45.060
uniform substance. It contains water, proteins, lipids, connective tissue, and
26
00:01:45.099 --> 00:01:49.400
mineralized structures such as bones and teeth. Different chemicals interact
27
00:01:49.420 --> 00:01:53.930
with these components in different ways. Hydrofluoric acid can cause
28
00:01:53.950 --> 00:01:57.950
severe cancer. tissue destruction, but the rapid, nearly complete disappearance
29
00:01:57.989 --> 00:02:01.469
of a body is not a realistic representation of the
30
00:02:01.510 --> 00:02:05.530
chemical behavior. How about the matter of the bathtub? Hydrofluoric
31
00:02:05.609 --> 00:02:09.300
acid is famous for attacking glass and certain silica-containing materials.
32
00:02:09.900 --> 00:02:12.639
This is one reason it requires specialized handling in industrial
33
00:02:12.659 --> 00:02:16.780
and lab environments. However, a household bathtub is not necessarily
34
00:02:16.800 --> 00:02:20.199
made from the same materials as lab glass. Bathtubs may
35
00:02:20.259 --> 00:02:25.539
contain acrylic, fiberglass composites, porcelain, or other materials. The show's
36
00:02:25.580 --> 00:02:29.080
dramatic destruction of the bathtub and supporting floor, therefore, cannot
37
00:02:29.099 --> 00:02:32.500
be explained simply by saying that hydrofluoric acid dissolves everything.
38
00:02:33.379 --> 00:02:36.379
The chemical is highly selective in its reactions, and that's
39
00:02:36.400 --> 00:02:39.659
what makes this scene such an interesting example of Hollywood chemistry.
40
00:02:40.280 --> 00:02:44.569
The writers correctly identified a substance with unusually dangerous toxicological properties,
41
00:02:45.310 --> 00:02:48.349
but exaggerated the ability to rapidly destroy large amounts of
42
00:02:48.409 --> 00:02:54.060
biological and structural material. There are also limitations to evaluating
43
00:02:54.080 --> 00:02:57.939
the scene. The fictional chemical concentration, exposure, and construction materials
44
00:02:57.990 --> 00:03:02.509
are not established precisely enough to reconstruct the event. The
45
00:03:02.550 --> 00:03:06.729
broader scientific conclusion is clear, though. Hydrofluoric acid is very,
46
00:03:06.810 --> 00:03:09.330
very hazardous, but not because it behaves like a universal
47
00:03:09.389 --> 00:03:14.349
solvent capable of dissolving everything. Its most frightening properties involve
48
00:03:14.400 --> 00:03:18.379
its ability to penetrate tissue and disrupt essential biochemical processes.
49
00:03:19.819 --> 00:03:22.120
The real chemistry could be more disturbing than the fictions.