Dancing naphthalene balls

In an earlier post, I talked about dancing sodium (here is the link). It involved high temperatures and could be called a little risky venture. In this post, we will see how we can make naphthalene balls dance in a glass.

Items needed: A glass or cylinder, oxalic acid, naphthalene balls, sodium bicarbonate (baking soda).

How to do it: In a glass of water(about 300 ml), mix about 30 grams of oxalic acid and stir to dissolve. Keep a little room in the glass. Put few naphthalene balls in the glass.

Now, prepare another solution of baking soda. Add a little of this solution to the glass which has the naphthalene balls.

Immediately you can see the solution bubbling and very soon the naphthalene balls will go up and down in a constant motion till the effervescence(bubbling) lasts.

What happens: Acid + soda produces carbon dioxide, whose bubbles get adhered to the surface of the naphthalene balls, and take them up when buoyant enough.

Extra tip: Same can be performed with soda water, but one has less control, which does take some of the fun away!

Caution: Oxalic acid is very toxic. Try not to handle with bare hands. Wash everything thoroughly when done.