The theme for this week’s Unplugged Project was powder. I’ll admit that this particular choice was somewhat premeditated since I thought a baking soda project would be fun. Baking soda is a powder, right?
Fondly remembering a baking soda boat that came in a cereal box once when I was a child, I suggested we try and make one. My children were enthusiastic but leery, remembering a particularly violent baking soda volcano we made one time!
I am sure they were rolling their eyes and thinking:
“Oh no, here goes Mom with the baking soda again.”
Is that what they’ll remember about me as adults?
“I don’t remember much about Mom, but she did like playing with baking soda and vinegar.”
I found instructions here on the PBS Zoom website for a boat made out of a plastic bottle. Never being able to simply do what instructions say, I had to experiment, so we tried a sippy cup boat too!
We needed baking soda, vinegar, and our bottle and cup.
Using a hammer and nail, we made a hole in the cap of the bottle. The hole is the exhaust pipe through which the carbon dioxide gas escapes propelling the “boat” through the water.
The sippy cup already had holes of course, but I covered up the vent hole with some masking tape so the only vents would be in the spout.
Supplies in hand, we eagerly headed off to the bathroom and put some water in the bathtub.
The Zoom website suggested wrapping the baking soda in toilet paper to slow the reaction. Remembering my volcano, I thought this might be wise advice.
We poured baking soda onto a strip of toilet paper:
And rolled it up:
We tried the sippy cup first and poured in some vinegar.
Next we put in a few marbles to weigh down the spout (where the “exhaust holes” are), so it would be underwater. Coins work too. It is important that the exhaust holes be under the water line so there will be more resistance (of the water) to propel the boat.
The kids cringed when I dropped in the toilet paper package containing the baking soda.
I quickly put the cap on and placed the cup in the tub. The cup whizzed around the tub accompanied by many oohs and aahs.
The toilet paper worked nicely to delay the reaction giving me time to put the top on, but on the second attempt the toilet paper clogged the exhaust hole stopping the “boat.”
We tried the bottle too. Same procedure: vinegar, toilet paper/baking soda and marbles. The bottle sailed around the tub.
Since we were having clogging problems with the toilet paper, we also got brave and dumped the baking soda in, poured in some vinegar and tried to get the top on quickly. Unfortunately we were never able to be quick enough, and those boats didn’t work as well since, as you can see here, a large part of the chemical reaction occurred before the top was on.
In light of my baking soda and vinegar obsession, this could become quite a project: how to control the reaction without clogging, what sized hole produces the best results, what proportions of baking soda and vinegar generate the most power. Nerd heaven! Look out for a blog post one day with my perfected version of this project.
My kids went on to create their own experiment with baking soda and vinegar in a plastic wipe box:
Fortunately we ran out of baking soda before they were able to blow the box open!
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LINKS:
Chemistry and ideas: Baking Soda and Vinegar Science
Real Science: Ask a Scientist-Vinegar and Baking Soda
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Did you join us this week for a powder Unplugged Project? If so, please link to your powder project post (not your blog) below. If you didn’t join in, then please don’t link but read more about how it all works here. We’d love to have you!
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The theme for next week’s Unplugged Project will be:
Magic
Have fun!
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