Thanks so much to everyone who participated in our Zoom call! As an added bonus, your PTO has provided my video show for you to enjoy, too! If you have your kit but missed the show, you will see some of the things we did with those materials in this video. And you guys can see more fun science demos, too. Also, if you’d like to see even more and keep up with my latest experiments, check out the links below!
But first . . . why did our vinegar and baking soda get cold?
We had a great question on our call last night, and I was excited to look for an answer. A student asked why the vinegar and baking soda got cold. This was both a great observation and a really great question. I didn’t know the answer, but I found one for us, and it is pretty neat!
When you mix baking soda and vinegar together, their parts are rearranged to need to rearrange to form carbon dioxide (used to fill our balloons!), water, and dissolved sodium acetate. That’s our chemical reaction. This requires energy, and that energy is heat. As that heat is absorbed, our solution becomes cold.
The vinegar and baking soda reaction absorbs heat, which is called an endothermic reaction. You may have seen our elephant toothpaste reaction steaming. It gives off heat, which is called an exothermic reaction. Those are big words. You may not hear them again until high school chemistry!
Thanks for the great question! I’m always excited to learn something new! A student with curiosity and observations like that has a lot going for him!
Video Index (find your favorite parts!):
21:20 Objects in liquid nitrogen
24:07 Leidenfrost effect with liquid nitrogen
25:18 Leidenfrost effect in kitchen
27:22 Bernoulli’s principle explained
28:19 Bernoulli’s principle examples
29:51 Isopropyl combustion
34:31 Elephant toothpaste reaction
36:55 Potential energy and kinetic energy
38:55 Hadrosaur egg
39:19 Making elephant toothpaste together
Supplies for the Zoom Show:
Our science activities are all safe, but there is potential for them to make a little bit of a mess. This is intended to be a family experience, and the youngest kids in particular will enjoy some supervision. A workspace like a kitchen table, counter, or hard floor is ideal for ease of clean up. Don’t set up for this one on Great Aunt Mildred’s antique dining room table!
Your PTO has provided kits containing all of the materials below EXCEPT for vinegar, baking soda, and an empty water or soda bottle. If you do not have these items, you can still have fun. There will just be one experiment that you won’t be able to do with the group.
for carbon dioxide balloons:
- Vinegar (about 8 ounces; I use white vinegar, but any you have is fine)
- Baking soda (about 2 tablespoons)
- Empty 16 oz water bottle or soda bottle
for film canister rockets:
- Alka Seltzer tablets
- Film canister
for Bernoulli’s principle:
- Bendable straw
- Ping Pong ball
Optional, but recommended:
- Measuring cup and spoon, small funnel (optional, but they may make things easier)
- trash bag or similar to lay out for a workspace
Optional, but fun:
- Hair dryer (plugged in and ready to go!)
The Yuck for Kids science blog is where I share new science videos, projects, and fun facts, recently on at least a weekly basis. There is some really cool stuff in the blog and some even cooler stuff coming up soon, so if you enjoy these types of demonstrations you might want to check it out!