Well now here’s a tasty way to bring some science into your winter afternoon. Or to add a sweet twist to your science. Whichever way you spin it to your kids, who can possibly protest a science experiment that ends a cup of hot chocolate?
I started out by posing a hypothetical to Travis. If we made him hot cocoa for a snack, which would dissolve fastest: cocoa in a cup of cold water, one of medium (room temperature) water, or one with hot water. He picked hot (great!), so I guessed cold to play devil’s advocate. Now it was time to test our hypotheses.
Set out three heat-proof cups and fill each with 6 ounces of water.
Travis proudly helped fill the first two cups. Use caution when pouring the hot water, a step best left to grownups.
We then added 1 tablespoon of hot cocoa mix to each cup, one at a time, starting with the cold water. We tried to be scientific by timing our results with a handy stopwatch, although I confess our scientific method was spotty.
The chocolate in the cold water didn’t go anywhere, remaining powdery and clumpy even after lots of stirring. Truth be told, we have no idea how long it would have taken to dissolve, but far past our attention span on the stopwatch.
The hot water dissolved the cocoa in 10 seconds flat – a neat comparison that grabbed Travis’s attention.
Results for our medium water were a little fuzzy because it was probably hotter than it should have been. I had hoped to have water exactly at room temperature, but it was warm from sitting in the tea kettle. So that only took about 16 seconds to dissolve.
Either way, Travis got to enjoy a cup of cocoa at the end (from the hot cup, of course), and picked up a little science about how heat breaks apart molecules along the way.