With a tip of the hat to my good friend, Scope, I bring you this week's version of blowing shit up. Except...well...I'm not blowing shit up. But, I am ripping holes in things with cascades of molten metal.
A couple of weeks ago, back when I showed the pumpkin and the thermite reaction, Mr. C asked the question "It said it [thermite] could burn through the hood of a car, the engine block, and concrete. True?"
I could simply tell you the answer. But if Seymour Skinner has taught me anything about the conservation of angular momentum, it's that people learn better when you show them rather than explain to them. So, I humbly offer the video below.
Heh. They destroyed that car because it was French.
And, yeah, I know. There was no concrete under the car, so I didn't technically answer Mr. C's question. However, I can assure you that, with enough thermite, it will destroy the concrete underneath the car's engine block and bonnet. Remember, as they point out in the above clip, thermite burns at around two and a half thousand degrees Celsius. That's quite warm.
But, thermite's not just good for destroying the engine block of a car. And, frankly, I'd be doing you, my friends, a disservice if I didn't show you that thermite can also be used for the entire, wanton destruction of the entire car.
Don't believe me? Well, then you don't watch enough Mythbusters...
Sorry about the shitty quality of the film. It's the best I could find.
Okay, so Jamie said that thermite burns at 4500 degrees. That was in degrees Fahrenheit. Still, it's damned hot, as evidenced by the smoldering lump of bubbly steel left in the wake of Adam and Jamie's little "experiment."
So, if this is an experiment, then what is the reaction? Well, a "thermite" reaction is simply a metal oxide and another metal mixed together and, when heated, the oxide is transferred and a lot of extra heat is released during the course of the single-replacement reaction. For what we've seen twice above, this is the balanced chemical equation:
I say the oxide is "transferred", but that may not be entirely true. The oxygen could, conceivably, come from the atmosphere. I don't know if anyone has done isotopic studies to make sure taht the oxide from the iron is ending up on the aluminum. Also, I don't know if 18O (O-eighteen) is stable at two and a half thousand degrees.
That's just one type of thermite, though. Another common form, used in welding (especially in the rail industry), uses copper instead of iron:
Anyway, the net product is one bitching hot reaction and, as Jamie says in the second video, it's really, really satisfying. Fortunately, the tires blew up during the course of the melting of the car with thermite. Hooray thermite! Hooray explosions!