Saturday, April 1, 2017

Baking Soda Volcano

Materials Needed:
  • Vase
  • Playdough (preferably used because the Playdough will be ruined at the end of this experiment)
  • Baking soda
  • Food coloring (optional)
  • Vinegar
  • If working inside, use a tray or work in the bathtub or sink (because it will be a lot of bubbly mess)
  • If working outside, only a hose is necessary to wash the mess away

  1. Cover the vase with playdough to make it look like a volcano!
  2. Pour baking soda into the covered vase
  3. Add a few drops of food coloring into the vase (optional)
  4. Pour in vinegar
  5. Watch the volcano erupt!!

The Science:
  • Baking soda is sodium bicarbonate, and vinegar is acetic acid. Therefore, when the two are mixed, carbonic acid is formed. Carbonic acid immediately decomposes into water and carbon dioxide, so the bubbly reaction you see is the carbon dioxide escaping.


Engineering Egg Drop Challenge!

Goal/Objective: Design a carrier for a raw egg that will prevent it from breaking when dropped from 10 feet high.


Raw egg
A ladder or second story window

Pick some of the following materials to use to construct the carrier (less materials=more challenging):

Toilet paper
Plastic bags
Masking tape

Activity Instructions:

  1. Only use the materials listed above to construct a carrier.
  2. Time yourself! (Try to make it in 10 minutes on your first try)
  3. If you have a scale, weigh what you’ve built. Eventually, try to make your package lightweight and strong.
  4. Cover the ground with newspaper just in case your first couple drops do not end with the egg in perfect condition.
  5. Goodluck and don’t be afraid to get creative and have some fun!

Some questions to think about:
What forces are acting on the egg as its falling?
If your design did not succeed in keeping the egg from breaking, how would you change it?

Remember to try again if it doesn’t workout the first time! And, if it does work the first time, think about how you can improve your egg carrier now that you have tested your first one.

Bonus: See how lightweight you can make your egg carrier. Also see how high you can drop the egg from without it breaking.

Lava Lamp Polarity demonstration

What you’ll need:
  • one large plastic bottle (like a soda bottle)
  • ¾ cup vegetable oil
  • ¼ cup water
  • food coloring
  • Alka-Seltzer tablet

What to do:
  • Pour the water into the bottom of the bottle
  • Pour the oil in on top, and wait a few minutes for the water and oil to separate
  • Add some drops of food coloring until the water gets darkly colored
  • Break the Alka-Seltzer tablet in to a couple of pieces, and drop one of the pieces into the water
  • Watch what happens to the bubbles as the tablet dissolves
  • Tip: shine a light through the bottom of the bottle to make it look even more like a lava lamp!

How it works:
Water is a polar molecule, which means it has an uneven charge distribution within the molecule. This means it doesn’t mix or interact with vegetable oil, which is a nonpolar molecule. This concept is best summarized as ‘like dissolves like’
Notice that the food coloring only mixes with the water, which tells us that the food coloring molecules must also be polar.
When you add the Alka-Seltzer, it begins to release carbon dioxide bubbles which attach to the water blobs that have formed in the bottle and causes them to float to the top. This is what creates the colored bubble effect in the lava lamp!