Monday, March 9, 2015

Baking Soda Stalactites

After our modified Jello experiment, my daughters and I set out to make baking soda stalactites.  In principle the experiment is easy to set up.  It requires two jars of water, both filled with dissolved baking soda.  Next take a string, dropping each end into each jar of water.  Let the string droop between the jars over a plate.  You made need paper clips or weights to keep the string submerged in the water.

Over a few days, the water should travel up the string and drip onto the plate.  The baking soda carried with the water will remain in the string, slowly creating a hanging stalactite.  That's what is supposed to happen.  That did not happen in our experiment.  Stalactites built up, but only at the string just as it emerged from the water.  Water did not soak through the string as expected.

That clump on the string is a baking soda stalactite ball.  One formed coming out of each jar.  So the experiment worked, sort of.  We created stalactites, just not where we thought we would.  So what went wrong?  I'm not sure.  My guess is the string.  We may need a thinner string.  The string was on the thicker side and this may have prevented baking soda water from traveling all the way to the middle.  We gave ourselves the task of getting different types of string and testing out which works better.

The experiment didn't work out as planned, but we have ideas to move forward and that's science in action!

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