science for tinies: immiscible liquids

[psocoptera]

Project: Will It Mix?
Materials: water, dyed pink; peanut oil, not so much dyed green as speckled with innumerable tiny green droplets because, haha, food coloring is also immiscible with oil; mixing vessel
Explanatory details: pour together, observe
How did it go: Laboratory erupted into chaos when the PI poured the pink water not *into* the mixing vessel but mostly *next to* the mixing vessel; assistant promptly sprang into action with towels, but pursuit of science was delayed. Experiment eventually resumed with assistant doing the work and PI observing and taking credit, as is the natural order of things anyways. Very nice layering for a minute or two then food dye start coming down from the oil into the pink water, turning it murky and confusing the issue (by which time we had conveniently set it aside); if you do this one you probably don't want to try to dye the oil.
Things we talked about: One liquid can float on another liquid if they don't want to mix; oil is lighter than water, so it goes on top.
What Junie got out of it: Naked duck science! (In a tub of water, not the oil mix, if that wasn't clear. She asked for the duck and I figured, wait, why put on new clothes just to play with more water? It's warm... We've also added a new item, a cork, which turns out to float.)

Comments

science for not so tinies

[(Anonymous)]

The sad this is I tried this experiment with a 5, 7 and 9 year old and they were amazed at the result, as well as the following one that showed that another thick substance (syrup) sinks.

Re: science for not so tinies

[psocoptera.livejournal.com]

Wild guess - do you like ranch dressing? I feel like my early exposure to the concept of oil and water was in shaking up the salad dressing, but my parents liked Italian. If you mostly eat dressing you don't need to mix, I'm not sure what the next most likely encounter for oil and water would be - maybe fat floating to the top of soup when left to sit?

Also, you're never too old to be amazed by Science! I'm not sure who you are and thus it's slightly awkward to be lecturing you ::grin::, but I feel like part of the idea of science is that it's just fine to not know things, in fact, it's great to not know things and be surprised by results and have to ask very basic questions about why does it do that.

Re: science for not so tinies

[rivka17.livejournal.com]

ah oops. I don't know why but the default always seems to be for livejournal to post comments as anonymous even when I am logged in. The point was that by 4th grade our science program had certainly done that experiment several times and the reason i did the experiment with the kids is that the oldest was having problems understanding her science books explanation of density or the concept that some things can and will float on other things. I certainly learned about it at a much earlier age but then I was making my own brownies and other cooking in 2nd grade.

[tirerim.livejournal.com]

Hm, there must be oil-soluble dyes. I have no idea what they are, though.

[psocoptera.livejournal.com]

Oil paint??

[rivka17.livejournal.com]

yes but bad idea in this context. btw oil paints mostly sink in water, a small bit of them will float on the surface if you slowly add only a tiny bit. You can use this to create a pretty colored pattern on the water that if you gently swipe a piece of paper across will result in neat marbled paper. A better choice would probably be to use colored oils (extra vergin olive oil = green) (toasted sesame oil = brown)