Sunday, May 2, 2010

Homemade explosives, okay not exactly



I wanted to start this off by showing you all these movie clips of people who’ve claimed to “invent gun powder,” and then the silly uses they put it to in the movies.  Offhand I remembered Robin Hood Prince of Thieves, where they use it to distract the Sherriff.  And, the horrid movie Scorpion King where there’s some crazy inventor who is being held prisoner by the bad guy and he invents it, and they use it to escape somehow.  I know there’s a lot of others.  And it cracks me up/annoys me every time.

 

However, that was not going to happen without my taking a long time to watch through lots of clips labeled Robin Hood 5, or 12, and while I enjoy the movie.  If I want to write more than one post this week I can’t do that.  So, I guess I’ll just tell you about what we did.

 

Important note: I have learned there really is a reason they tell you to wear safety goggles when doing experiments.  I was always somewhat mocking of those warning, especially for simple little experiments, and then I did this:

 

So, that is what not to do.  My boys think that was hilarious and kept trying to get me to do it again.  Yeah, so not happening, it was rather painful.  I got lots of sympathy comments on Facebook, and was even told I got a free chemical peel facial doing that, still……..

 

Here’s when it went right:

 

Now to the science of this.  What you are doing is taking a bottle full of vinegar, and then adding a piece of napkin of toilet paper filled with baking soda and then stuffing a cork into it somewhat tight so the gas produced from the chemical reaction will force the cork to go out.  This is the same reason that when we do baking soda and vinegar volcanoes you get this foam that overflows the cup.

Things I learned in our 5 or 6 failures:

1.  Don’t put the cork on too tight, it needs to be tight, but not too tight.

2.  I think a normal water bottle would have worked better, think the soda bottle cap width.  Beggars can’t be choosers, and a friend was nice enough to give us a water bottle from her recycle bin.

3.  Make sure you have enough supplies to do it several times.  Either because it didn’t work the first few times, or because the kids want to do it “Again, again!”

4.  Wear safety goggles, and don’t lean over when the chemical reaction is still going on.

5.  Be aware of your current weather.  I had another explosion I was going to do, and had bought most of the supplies for, but one I had bought them, it became too windy for me to want to experiment with shooting matches.

 

I think Almost Unschoolers has done this before, or I remember watching a video of vinegar and baking soda overflowing in their backyard.  I know I first learned about this back when it was an object lesson for our Sunday School class.  I don’t remember what we were teaching the kids, but I know the class full of boys loved it and each had to take a turn at it.

 

So, has anyone else injured themselves for a science experiment?  I was just glad it wasn’t too serious, it just stung for a couple of hours.

As always, add up your science related post.  It doesn’t have to be an experiment, it could be a cool new book, a nature walk, whatever you did or found for science this week.

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