Dwayne’s Study Zombies

You know what I want to be after I get my GED? A spy. Yeah. Like James Bond. Seen the new flick? Yeah, with a fast car and all kindsa gadgets…that’s the thing, a spy’s gotta have gadgets, and that’s where science comes in. Science = kewl stuff.

Since I want to be a spy, I figured that I’d better find out about DISAPPEARING INK! That’s right. GED science for kewl spying. Okay, maybe you made it as a kid, but it’s still kewl. And there’s real science… science about acids and bases. I don’t mean acid rock and bass guitar, even though that’s kewl too.

Here’s the scoop on acids and bases: everything’s got a pH. That’s a measure of hydrogen ions (an atom with a positive charge…it’s missing an electron!). What you really gotta know is, the lower the pH, the more acidic something is, like lemon juice. You know, an acid. The higher the pH is, the more it’s a base, like baking soda or Drano. (Yup, bases and acids can both dissolve things… like gunk in your drains.)

What’s all this got to do with disappearing ink? Well, there are chemicals that turn color depending on whether they’re in acids or bases. Like litmus paper, if you ever used that in school. You can use it to see if something’s an acid or a base, because it changes color.

So, you take these chemicals and put them in water that reacts with carbon dioxide in the air. Ready for some chemistry?

CO₂ + H₂O -> H₂CO₃

Each of those letters stands for an atom…C is carbon, O is oxygen, and H is hydrogen. And the numbers show how many atoms. Well, CO₂ is carbon dioxide (that’s in the air). And H₂O is water (duh!). If you add them together… get them to combine, you get H₂CO_3.

What’s that? It’s got all the atoms from the other side of the equation. Do you see? Just like math. There’s 3 O’s on both sides, 1 C, and 2 H’s. So you don’t lose anything, just rearrange it. And you get CARBONIC ACID. That’s right, it’s acid. That means it changes the pH of the ink when it dries in the air. It gets more acid. And the stuff changes color. Poof! Presto! It disappears.

You can see a video of disappearing ink here: http://www.stevespanglerscience.com/content/science-video/disappearing-ink

You think it’s just a kid’s trick? Well, there’s different ways to disappear ink… it all depends on different kinds of science. Science shows you how different things act, what they do, and then clever people think of new ways to make them work…that’s technology! Now, some scientists have got new inks for tattoos that is “disappeared” with lasers, so they’re easy to remove if you don’t want ‘em anymore: http://technology.newscientist.com/article.ns?id=mg19025495.600&feedId=online-news_rss20

If only you could get a tattoo that disappeared and reappeared… hey, if you learn enough science, maybe you can invent it! So, do you get what acids and bases are? How about what chemistry equations mean? Remember that stuff for your GED…

This entry was posted on Monday, February 4th, 2008 at 8:41 am and is filed under Chemistry.
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