WEBVTT - How does Nitroglycerin work?

0:00:00.520 --> 0:00:03.600
<v Speaker 1>Welcome to brain Stuff from house stuff works dot com

0:00:03.600 --> 0:00:14.720
<v Speaker 1>where smart happens. Hi. I'm Marshall Brain with today's question,

0:00:15.000 --> 0:00:21.840
<v Speaker 1>how does nitroglycerin work? In eighteen forty six, scientists discovered nitroglycerin.

0:00:22.280 --> 0:00:25.439
<v Speaker 1>It's pretty simple to make. You start with nitric and

0:00:25.520 --> 0:00:29.320
<v Speaker 1>sulfuric acids in an ice bath and you slowly add

0:00:29.360 --> 0:00:32.120
<v Speaker 1>glycerin to it. You have to make sure to add

0:00:32.159 --> 0:00:35.120
<v Speaker 1>the glycerin at a slow enough rate to avoid a

0:00:35.159 --> 0:00:38.479
<v Speaker 1>temperature rise, because if the temperature rises, you can get

0:00:38.479 --> 0:00:42.680
<v Speaker 1>an explosion. The nitroglycerin that gets formed creates a layer

0:00:42.760 --> 0:00:45.920
<v Speaker 1>on top of the acid. If you extract this layer

0:00:46.080 --> 0:00:49.519
<v Speaker 1>stay with an eye dropper, you have the desired product.

0:00:50.000 --> 0:00:53.680
<v Speaker 1>It's pretty remarkable stuff, but not very stable. If you

0:00:53.720 --> 0:00:55.320
<v Speaker 1>take a drop of it and put it on a

0:00:55.320 --> 0:00:57.400
<v Speaker 1>piece of paper and put that piece of paper on

0:00:57.440 --> 0:01:00.360
<v Speaker 1>a countertop and tap it with a hammer, it will

0:01:00.400 --> 0:01:03.960
<v Speaker 1>explode with a loud pop. Just a few grams of

0:01:04.040 --> 0:01:09.200
<v Speaker 1>nitroglycerin can create an impressive explosion. Why is it explosive?

0:01:09.520 --> 0:01:13.280
<v Speaker 1>Compare a molecule of gasoline to a molecule of nitroglycerin

0:01:13.360 --> 0:01:17.520
<v Speaker 1>and you can see why. Gasoline contains eight carbon atoms.

0:01:17.560 --> 0:01:21.360
<v Speaker 1>And eighteen hydrogen atoms. If you light it, it combines

0:01:21.440 --> 0:01:24.319
<v Speaker 1>with oxygen in the air to burn. A gallon of

0:01:24.360 --> 0:01:27.480
<v Speaker 1>gas might produce a fireball when you burn it, but

0:01:27.600 --> 0:01:30.639
<v Speaker 1>it's not really an explosion because it has to suck

0:01:30.680 --> 0:01:33.880
<v Speaker 1>in oxygen from the air to burn, and that takes time.

0:01:34.680 --> 0:01:39.360
<v Speaker 1>A nitroglycer molecule has three carbon atoms, five hydrogen atoms,

0:01:39.440 --> 0:01:44.319
<v Speaker 1>three nitrogens, and an impressive nine oxygen atoms. In other words,

0:01:44.560 --> 0:01:48.520
<v Speaker 1>each nitroglycer and molecule contains almost all the oxygen needed

0:01:48.520 --> 0:01:54.160
<v Speaker 1>for complete combustion, so it can burn much faster explosively. However,

0:01:54.520 --> 0:01:58.480
<v Speaker 1>the instability of nitroglycerin is a problem. If you drop

0:01:58.560 --> 0:02:02.520
<v Speaker 1>nitroglycerin or bang it or round, it can explode spontaneously.

0:02:03.120 --> 0:02:06.640
<v Speaker 1>Alfred Nobel is the first guy to figure out a

0:02:06.680 --> 0:02:09.240
<v Speaker 1>way to stabilize it. He mixed it with something like

0:02:09.320 --> 0:02:15.480
<v Speaker 1>sawdust to create dynamite, which is much more stable. For

0:02:15.600 --> 0:02:18.000
<v Speaker 1>more on this and thousands of other topics, visit how

0:02:18.080 --> 0:02:20.720
<v Speaker 1>stuff Works dot com. To learn more about the podcast,

0:02:20.919 --> 0:02:23.440
<v Speaker 1>click on the podcast icon in the upper right corner

0:02:23.480 --> 0:02:26.520
<v Speaker 1>of our homepage. The house Stuff Works iPhone app has

0:02:26.560 --> 0:02:29.080
<v Speaker 1>a ride. Download it today on iTunes.