Floating bubbles

This has to be one of the coolest experiments we've done. Since Jr. Scientist E loves bubbles, I've been trying to find some more bubbly experiments to do with her (although she never gets tired of watching baking sod and vinegar fizz, I sure do). I ran across a cool one where you create carbon dioxide by mixing baking soda and vinegar and then you use bubble mix and blow some bubbles into the container. Since carbon dioxide is heavier than the air inside the bubble mix bubbles, the bubbles go into the container and then come to a rest in mid-air (resting on top of the invisible carbon dioxide). The bubbles will pop if they hit the edge of the container, so you need to do this in a large container with a lot of baking soda and vinegar (ah Costco, the kitchen scientist's best friend). The effect is absolutely jaw dropping and both Jr. scientists A and E loved it.

Hidden bubbles

We found this effect quite by accident. One of Jr. scientist A's new favorite things to do is to mix various ingredients together to see what happens - I think we have a budding chemist! We were adding things to red cabbage-dyed water (a pH indicator). As expected, when we added baking soda, the mixture turned blue, and adding vinegar to the same mixture caused it to bubble and then turn red. What caught us by surprise was that we next added salt and the mixture bubbled again. I had never heard of salt causing a chemical reaction resulting in bubbles, so we did some more investigating. Adding more salt turned the mixture from red (acidic) to purple, as would happen when you added a base, making us think that salt was a base (it's actually neutral). We tried combining vinegar and salt in another cup and got a rather unexciting cup of salty vinegar with no bubbles. After some google-ing, we found out that the salt wasn't actually creating bubbles, it was releasing the carbon dioxide bubbles trapped in our mixture after the baking soda and vinegar reaction. We decided to try adding salt to soda and got instant bubbles again. We even were able to create a little soda fountain (nowhere near as big as the mentos and diet coke reaction, but still cool). Jr scientists A and E both got quite a kick out of this accidental experiment, and I think it will become a new regular experiment.

Fizzy colors

Looking for a good experiment for Jr. scientist E, at my wife's suggestion I went back to an old fizzy standard - mixing baking soda and vinegar. To make it more interesting, I put down a drop of red food coloring and a drop of blue food coloring, with the baking soda and vinegar in the middle. As the fizzy mess spread, it took up the food coloring. Jr. scientist E just stared intently at the bubbly concoction (I think with interest!), getting transfixed each time I added more baking soda or vinegar to restart the fizzing.

Good clean fun

Today we did an experiment that Jr. scientist A named the messy messy experiment. We made some bubble mix (water + dish detergent)and headed outside to play with bubbles. We used a funnel to make different sized bubbles (depending which end we blew into) and tried out a new bubble maker -two straws connected with string- with mixed results. The experiment ended with playing around in puddles of bubble mix and lots of fun.

Make-shift bubble blower

I promised jr. scientist A that we would make bubbles, but I couldn't find any of our bubble blowers. We decided to try to make some with objects we had around the house. One of the best bubble makers was an empty toilet paper roll. We dipped it in some bubble mix and then blew into the other end. If we blew slowly we got really big bubbles (although they often popped while still attached). It was a lot of fun, and when the toilet paper roll got soggy, we just let it sit for a couple hours and it was ready to be used again.

Unconventional bubble maker

Once again we used pressure created by warming air. We took a frozen empty bottle (my new motto is always keep an empty bottle in the freezer) and dipped the opening in bubble mix to form a soapy film over the opening. We put the bottle down and slowly a bubble started growing out of bottle. Squeezing the bottle, we could make the bubble grow quicker - o.k., it's just from the warmth from my hands, but it looks like I'm squeezing the bubble out of the bottle. Jr. scientist A had great fun popping each bubble as it formed.