Dissolving Fizzy Coal: Christmas Science

Usually we focus on crafting around the holidays, but my kids love science activities too. Especially fizzy, bubbling ones involving vinegar and baking soda. I made some disappearing lumps of "coal" that dissolved to reveal some Christmas surprises.

This is basically our dissolving rocks recipe made with black food coloring, but it's fun for the holidays. I made a dough of baking soda and water. It needs to be wet enough to be stick together but not so wet that it won't hold its shape. I just added a little water at a time. Then I tinted it with black food coloring to make it look like coal.

I had some plastic Christmas rings from Walmart that worked perfectly as surprises to hide inside.

 I formed the dough around them and let them dry overnight.

Maybe I should have called this activity dissolving reindeer poop.

When we were ready, I set out some bowls of vinegar and the coal and let the kids experiment. I forgot to put a cookie sheet under everything which was a mistake, because when they dropped the coal into the vinegar, it bubbled and fizzed like crazy and went everywhere.

I also gave them medicine droppers and spoons and this activity kept them busy for a long time. Longer than it took to dissolve the coal, because they kept pouring and mixing and making potions.

 
If you want more Christmas science fun, be sure to check out the Christmas science challenge hosted by Inspiration Laboratories and Science Sparks.