Thursday, February 14, 2013

Valentine's Day Science: Frozen Vinegar Hearts!

What kid doesn't love baking soda and vinegar? Okay, as individual ingredients, maybe not. But as reactive counterparts, heck yeah! These two ingredients - and some hearts, of course - make for the perfect Valentine's Day activity.

We all know about the standard baking soda and vinegar reaction: vinegar is an acid; baking soda is a base; and together you get a chemical reaction that produces water and salt. But have you ever thought about what happens when you freeze the vinegar or baking soda or both...? Well, you better experiment to find out!

Here's what you'll need:
  • Baking Soda
  • Vinegar
  • Water
  • Freezer Trays/Molds (In heart shapes for festive-ness)
  • Red & Blue Food Coloring
Start off by filling your freezer trays or molds half full of water and half full of vinegar. If you use more vinegar, you'll get more bubbles faster later. Once the trays are full, add a drop or two of food coloring and freeze those bad boys. While they're in the freezer, add one teaspoon of baking soda to one cup of water and stir it until it dissolves. Make this mixture blue and put it in a pan or bowl. 

Once your vinegar hearts are frozen, pull them out and start exploring. Start by putting the frozen hearts in the baking soda/water mixture. Ass the ice melts, the baking soda and vinegar will react. What does this look like? (You'll observe bubbles, excitement and the colors mixing.)

Switch things up and add baking soda directly to the frozen vinegar. To illustrate that baking soda and water don't react, try adding baking soda to a normal frozen ice cube and note what happens (nothing).

Remember: this is all about exploration and investigation so make observations as you go along. Even if it means that you notice that the ice heart floats on the water. More ideas for this experiment and more Valentine's Day activities can be found here.